package store

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"strconv"
	"strings"
	"time"

	"github.com/easyai/easyai-ai-gateway/apps/api/internal/auth"
	"github.com/jackc/pgx/v5"
)

type TaskListFilter struct {
	Query       string
	ModelType   string
	CreatedFrom *time.Time
	CreatedTo   *time.Time
	Page        int
	PageSize    int
}

type TaskListResult struct {
	Items    []GatewayTask
	Total    int
	Page     int
	PageSize int
}

func (s *Store) ListTasks(ctx context.Context, user *auth.User, filter TaskListFilter) (TaskListResult, error) {
	page := filter.Page
	if page <= 0 {
		page = 1
	}
	pageSize := filter.PageSize
	if pageSize <= 0 {
		pageSize = 50
	}
	if pageSize > 100 {
		pageSize = 100
	}
	offset := (page - 1) * pageSize
	gatewayUserID := localGatewayUserID(user)
	apiKeyID := ""
	userID := ""
	if user != nil {
		apiKeyID = strings.TrimSpace(user.APIKeyID)
		userID = strings.TrimSpace(user.ID)
	}
	if gatewayUserID == "" && userID == "" {
		return TaskListResult{}, ErrLocalUserRequired
	}
	queryPattern := ""
	if query := strings.TrimSpace(filter.Query); query != "" {
		queryPattern = "%" + query + "%"
	}
	args := []any{
		gatewayUserID,
		userID,
		apiKeyID,
		queryPattern,
		strings.TrimSpace(filter.ModelType),
		nullableTaskListTime(filter.CreatedFrom),
		nullableTaskListTime(filter.CreatedTo),
	}
	whereSQL := `
WHERE (
    (
      NULLIF($1, '')::uuid IS NOT NULL
      AND gateway_user_id = NULLIF($1, '')::uuid
    )
    OR (
      NULLIF($1, '')::uuid IS NULL
      AND NULLIF($2, '') IS NOT NULL
      AND user_id = $2
    )
  )
  AND (
    NULLIF($3, '') IS NULL
    OR api_key_id = $3
  )
  AND (
    NULLIF($4, '') IS NULL
    OR id::text ILIKE $4
    OR COALESCE(request_id, '') ILIKE $4
    OR kind ILIKE $4
    OR model ILIKE $4
    OR COALESCE(requested_model, '') ILIKE $4
    OR COALESCE(resolved_model, '') ILIKE $4
    OR COALESCE(api_key_id, '') ILIKE $4
    OR COALESCE(api_key_name, '') ILIKE $4
    OR COALESCE(api_key_prefix, '') ILIKE $4
    OR status ILIKE $4
    OR COALESCE(model_type, '') ILIKE $4
  )
  AND (
    NULLIF($5, '') IS NULL
    OR model_type = $5
  )
  AND (
    $6::timestamptz IS NULL
    OR created_at >= $6::timestamptz
  )
  AND (
    $7::timestamptz IS NULL
    OR created_at <= $7::timestamptz
  )`
	var total int
	if err := s.pool.QueryRow(ctx, `SELECT count(*) FROM gateway_tasks `+whereSQL, args...).Scan(&total); err != nil {
		return TaskListResult{}, err
	}
	queryArgs := append(args, pageSize, offset)
	rows, err := s.pool.Query(ctx, `
SELECT `+gatewayTaskColumns+`
FROM gateway_tasks
`+whereSQL+`
ORDER BY created_at DESC
LIMIT $8 OFFSET $9`, queryArgs...)
	if err != nil {
		return TaskListResult{}, err
	}
	defer rows.Close()

	items := make([]GatewayTask, 0)
	for rows.Next() {
		task, err := scanGatewayTask(rows)
		if err != nil {
			return TaskListResult{}, err
		}
		items = append(items, task)
	}
	if err := rows.Err(); err != nil {
		return TaskListResult{}, err
	}
	items, err = s.attachTaskAttempts(ctx, items)
	if err != nil {
		return TaskListResult{}, err
	}
	return TaskListResult{
		Items:    items,
		Total:    total,
		Page:     page,
		PageSize: pageSize,
	}, nil
}

func nullableTaskListTime(value *time.Time) any {
	if value == nil {
		return nil
	}
	return *value
}

func (s *Store) ClaimTaskExecution(ctx context.Context, taskID string, executionToken string, leaseTTL time.Duration) (GatewayTask, error) {
	if leaseTTL <= 0 {
		leaseTTL = 5 * time.Minute
	}
	var task GatewayTask
	manualReview := false
	err := pgx.BeginFunc(ctx, s.pool, func(tx pgx.Tx) error {
		var queuedReady bool
		var runningExpired bool
		var production bool
		var hasGatewayUser bool
		if err := tx.QueryRow(ctx, `
SELECT status = 'queued' AND next_run_at <= now(),
       status = 'running' AND (execution_lease_expires_at IS NULL OR execution_lease_expires_at <= now()),
       run_mode = 'production',
       gateway_user_id IS NOT NULL
FROM gateway_tasks
WHERE id = $1::uuid
FOR UPDATE`, taskID).Scan(&queuedReady, &runningExpired, &production, &hasGatewayUser); err != nil {
			return err
		}
		if !queuedReady && !runningExpired {
			return ErrTaskExecutionLeaseUnavailable
		}
		if runningExpired && production {
			var submissionAmbiguous bool
			if err := tx.QueryRow(ctx, `
SELECT COALESCE((
  SELECT (
    (status = 'running' AND upstream_submission_status IN ('submitting', 'response_received'))
    OR (status = 'failed' AND upstream_submission_status = 'submitting')
  )
  FROM gateway_task_attempts
  WHERE task_id = $1::uuid
  ORDER BY attempt_no DESC, started_at DESC
  LIMIT 1
), false)`, taskID).Scan(&submissionAmbiguous); err != nil {
				return err
			}
			if submissionAmbiguous {
				if _, err := tx.Exec(ctx, `
UPDATE gateway_tasks
SET status = 'failed',
    billing_status = CASE WHEN $2 THEN 'manual_review' ELSE 'not_required' END,
    billing_updated_at = now(),
    error = 'upstream submission result is unknown',
    error_code = 'upstream_submission_unknown',
    error_message = 'upstream submission result is unknown',
    locked_by = NULL,
    locked_at = NULL,
    heartbeat_at = NULL,
    execution_token = NULL,
    execution_lease_expires_at = NULL,
    finished_at = now(),
    updated_at = now()
WHERE id = $1::uuid`, taskID, hasGatewayUser); err != nil {
					return err
				}
				if hasGatewayUser {
					payloadJSON, _ := json.Marshal(map[string]any{
						"taskId": taskID, "classification": "upstream_submission_unknown",
					})
					if _, err := tx.Exec(ctx, `
INSERT INTO settlement_outbox (
  task_id, event_type, action, amount, currency, pricing_snapshot, payload,
  status, next_attempt_at, manual_review_reason
)
SELECT id, 'task.billing.review', 'release', reservation_amount, billing_currency,
       pricing_snapshot, $2::jsonb, 'manual_review', now(), 'upstream_submission_unknown'
FROM gateway_tasks
WHERE id = $1::uuid
ON CONFLICT (task_id, event_type) DO NOTHING`, taskID, string(payloadJSON)); err != nil {
						return err
					}
				}
				manualReview = true
				return nil
			}
		}
		var err error
		task, err = scanGatewayTask(tx.QueryRow(ctx, `
UPDATE gateway_tasks
SET status = 'running',
    execution_token = $2::uuid,
    execution_lease_expires_at = now() + ($3::int * interval '1 second'),
    locked_at = now(),
    heartbeat_at = now(),
    updated_at = now()
WHERE id = $1::uuid
  AND (
    (status = 'queued' AND next_run_at <= now())
    OR (status = 'running' AND (execution_lease_expires_at IS NULL OR execution_lease_expires_at <= now()))
  )
RETURNING `+gatewayTaskColumns, taskID, executionToken, int(leaseTTL/time.Second)))
		return err
	})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return GatewayTask{}, ErrTaskExecutionLeaseUnavailable
		}
		return GatewayTask{}, err
	}
	if manualReview {
		return GatewayTask{}, ErrTaskExecutionManualReview
	}
	return task, nil
}

func (s *Store) RenewTaskExecutionLease(ctx context.Context, taskID string, executionToken string, leaseTTL time.Duration) error {
	if leaseTTL <= 0 {
		leaseTTL = 5 * time.Minute
	}
	tag, err := s.pool.Exec(ctx, `
UPDATE gateway_tasks
SET execution_lease_expires_at = now() + ($3::int * interval '1 second'),
    heartbeat_at = now(),
    updated_at = now()
WHERE id = $1::uuid
  AND status = 'running'
  AND execution_token = $2::uuid`, taskID, executionToken, int(leaseTTL/time.Second))
	if err != nil {
		return err
	}
	if tag.RowsAffected() != 1 {
		var stillRunning bool
		if err := s.pool.QueryRow(ctx, `
SELECT COALESCE((SELECT status = 'running' FROM gateway_tasks WHERE id = $1::uuid), false)`, taskID).Scan(&stillRunning); err != nil {
			return err
		}
		if !stillRunning {
			return ErrTaskExecutionFinished
		}
		return ErrTaskExecutionLeaseLost
	}
	return nil
}

func (s *Store) MarkTaskRunning(ctx context.Context, taskID string, executionToken string, modelType string, normalizedRequest map[string]any) error {
	normalizedJSON, _ := json.Marshal(emptyObjectIfNil(normalizedRequest))
	tag, err := s.pool.Exec(ctx, `
UPDATE gateway_tasks
SET status = 'running',
	    model_type = NULLIF($3::text, ''),
	    normalized_request = $4::jsonb,
	    locked_at = now(),
	    heartbeat_at = now(),
	    updated_at = now()
WHERE id = $1::uuid
  AND status = 'running'
  AND execution_token = $2::uuid`, taskID, executionToken, modelType, string(normalizedJSON))
	if err != nil {
		return err
	}
	if tag.RowsAffected() != 1 {
		return ErrTaskExecutionLeaseLost
	}
	return nil
}

func (s *Store) ClaimAsyncQueuedTask(ctx context.Context, workerID string) (GatewayTask, error) {
	return scanGatewayTask(s.pool.QueryRow(ctx, `
WITH picked AS (
  SELECT id AS task_id
  FROM gateway_tasks
  WHERE async_mode = true
    AND status = 'queued'
    AND next_run_at <= now()
  ORDER BY priority ASC, created_at ASC
  LIMIT 1
  FOR UPDATE SKIP LOCKED
)
UPDATE gateway_tasks t
SET status = 'running',
    locked_by = NULLIF($1::text, ''),
    locked_at = now(),
    heartbeat_at = now(),
    updated_at = now()
FROM picked
WHERE t.id = picked.task_id
RETURNING `+gatewayTaskColumns, workerID))
}

func (s *Store) RequeueTask(ctx context.Context, taskID string, executionToken string, delay time.Duration, queueKey string) (GatewayTask, error) {
	if delay < time.Second {
		delay = time.Second
	}
	if delay > 10*time.Minute {
		delay = 10 * time.Minute
	}
	nextRunAt := time.Now().Add(delay)
	return scanGatewayTask(s.pool.QueryRow(ctx, `
UPDATE gateway_tasks
SET status = 'queued',
    locked_by = NULL,
    locked_at = NULL,
    heartbeat_at = NULL,
    execution_token = NULL,
    execution_lease_expires_at = NULL,
    next_run_at = $3::timestamptz,
    queue_key = COALESCE(NULLIF($4::text, ''), queue_key),
    error = NULL,
    error_code = NULL,
    error_message = NULL,
    updated_at = now()
WHERE id = $1::uuid
  AND status = 'running'
  AND execution_token = $2::uuid
RETURNING `+gatewayTaskColumns, taskID, executionToken, nextRunAt, strings.TrimSpace(queueKey)))
}

func (s *Store) SetTaskRiverJobID(ctx context.Context, taskID string, riverJobID int64) error {
	if riverJobID <= 0 {
		return nil
	}
	_, err := s.pool.Exec(ctx, `
UPDATE gateway_tasks
SET river_job_id = $2,
    updated_at = now()
WHERE id = $1::uuid`, taskID, riverJobID)
	return err
}

func (s *Store) SetTaskRemoteTask(ctx context.Context, taskID string, executionToken string, attemptID string, remoteTaskID string, payload map[string]any) error {
	payloadJSON, _ := json.Marshal(emptyObjectIfNil(payload))
	return pgx.BeginFunc(ctx, s.pool, func(tx pgx.Tx) error {
		tag, err := tx.Exec(ctx, `
UPDATE gateway_tasks
SET remote_task_id = NULLIF($3::text, ''),
    remote_task_payload = $4::jsonb,
    updated_at = now()
WHERE id = $1::uuid
  AND status = 'running'
  AND execution_token = $2::uuid`,
			taskID,
			executionToken,
			remoteTaskID,
			string(payloadJSON),
		)
		if err != nil {
			return err
		}
		if tag.RowsAffected() != 1 {
			return ErrTaskExecutionLeaseLost
		}
		if strings.TrimSpace(attemptID) == "" {
			return nil
		}
		_, err = tx.Exec(ctx, `
UPDATE gateway_task_attempts
SET remote_task_id = NULLIF($2::text, ''),
    response_snapshot = COALESCE(response_snapshot, '{}'::jsonb) || jsonb_build_object('remote_task_payload', $3::jsonb)
WHERE id = $1::uuid`,
			attemptID,
			remoteTaskID,
			string(payloadJSON),
		)
		return err
	})
}

func (s *Store) SetAttemptUpstreamSubmissionStatus(ctx context.Context, attemptID string, status string) error {
	switch status {
	case "not_submitted", "submitting", "response_received":
	default:
		return fmt.Errorf("invalid upstream submission status %q", status)
	}
	_, err := s.pool.Exec(ctx, `
UPDATE gateway_task_attempts
SET upstream_submission_status = $2,
    upstream_submission_updated_at = now()
WHERE id = $1::uuid`, attemptID, status)
	return err
}

func (s *Store) CancelQueuedTask(ctx context.Context, taskID string, message string) (GatewayTask, bool, error) {
	message = strings.TrimSpace(message)
	if message == "" {
		message = "任务已取消"
	}
	tag, err := s.pool.Exec(ctx, `
UPDATE gateway_tasks
SET status = 'cancelled',
    error = NULLIF($2::text, ''),
    error_code = 'task_cancelled',
    error_message = NULLIF($2::text, ''),
    locked_by = NULL,
    locked_at = NULL,
    heartbeat_at = NULL,
    finished_at = now(),
    updated_at = now()
WHERE id = $1::uuid
  AND status = 'queued'
  AND COALESCE(remote_task_id, '') = ''`, taskID, message)
	if err != nil {
		return GatewayTask{}, false, err
	}
	if tag.RowsAffected() == 0 {
		return GatewayTask{}, false, nil
	}
	task, err := s.GetTask(ctx, taskID)
	if err != nil {
		return GatewayTask{}, true, err
	}
	return task, true, nil
}

func (s *Store) ListRecoverableAsyncTasks(ctx context.Context, limit int) ([]AsyncTaskQueueItem, error) {
	if limit <= 0 {
		limit = 500
	}
	rows, err := s.pool.Query(ctx, `
SELECT id::text, priority, next_run_at
FROM gateway_tasks
WHERE async_mode = true
  AND (
    status = 'queued'
    OR (status = 'running' AND (execution_lease_expires_at IS NULL OR execution_lease_expires_at <= now()))
  )
ORDER BY priority ASC, created_at ASC
LIMIT $1`, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	items := make([]AsyncTaskQueueItem, 0)
	for rows.Next() {
		var item AsyncTaskQueueItem
		if err := rows.Scan(&item.ID, &item.Priority, &item.NextRunAt); err != nil {
			return nil, err
		}
		items = append(items, item)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}
	return items, nil
}

func (s *Store) CreateTaskAttempt(ctx context.Context, input CreateTaskAttemptInput) (string, error) {
	requestJSON, _ := json.Marshal(emptyObjectIfNil(input.RequestSnapshot))
	metricsJSON, _ := json.Marshal(emptyObjectIfNil(input.Metrics))
	pricingJSON, _ := json.Marshal(emptyObjectIfNil(input.PricingSnapshot))
	tx, err := s.pool.Begin(ctx)
	if err != nil {
		return "", err
	}
	defer tx.Rollback(ctx)

	var attemptID string
	err = tx.QueryRow(ctx, `
INSERT INTO gateway_task_attempts (
  task_id, attempt_no, platform_id, platform_model_id, client_id, queue_key,
  status, simulated, request_snapshot, metrics, pricing_snapshot, request_fingerprint,
  upstream_submission_status, upstream_submission_updated_at
)
VALUES (
  $1::uuid, $2::int, NULLIF($3::text, '')::uuid, NULLIF($4::text, '')::uuid, NULLIF($5::text, ''), $6,
  $7, $8, $9::jsonb, $10::jsonb, $11::jsonb, NULLIF($12, ''),
  'not_submitted', now()
)
RETURNING id::text`,
		input.TaskID,
		input.AttemptNo,
		input.PlatformID,
		input.PlatformModelID,
		input.ClientID,
		input.QueueKey,
		firstNonEmpty(input.Status, "running"),
		input.Simulated,
		string(requestJSON),
		string(metricsJSON),
		string(pricingJSON),
		input.RequestFingerprint,
	).Scan(&attemptID)
	if err != nil {
		return "", err
	}
	if _, err := tx.Exec(ctx, `
UPDATE gateway_tasks
SET attempt_count = GREATEST(attempt_count, $2::int), updated_at = now()
WHERE id = $1::uuid`, input.TaskID, input.AttemptNo); err != nil {
		return "", err
	}
	return attemptID, tx.Commit(ctx)
}

func (s *Store) CreateTaskParamPreprocessingLog(ctx context.Context, input CreateTaskParamPreprocessingLogInput) (string, error) {
	actualInputJSON, _ := json.Marshal(emptyObjectIfNil(input.ActualInput))
	convertedOutputJSON, _ := json.Marshal(emptyObjectIfNil(input.ConvertedOutput))
	changesJSON, _ := json.Marshal(input.Changes)
	if input.Changes == nil {
		changesJSON = []byte("[]")
	}
	modelSnapshotJSON, _ := json.Marshal(emptyObjectIfNil(input.ModelSnapshot))
	var attemptNo any
	if input.AttemptNo > 0 {
		attemptNo = input.AttemptNo
	}
	var id string
	err := s.pool.QueryRow(ctx, `
INSERT INTO gateway_task_param_preprocessing_logs (
  task_id, attempt_id, attempt_no, model_type, platform_id, platform_model_id, client_id,
  changed, change_count, actual_input, converted_output, changes, model_snapshot
)
VALUES (
  $1::uuid, NULLIF($2::text, '')::uuid, $3::int, NULLIF($4::text, ''),
  NULLIF($5::text, '')::uuid, NULLIF($6::text, '')::uuid, NULLIF($7::text, ''),
  $8, $9::int, $10::jsonb, $11::jsonb, $12::jsonb, $13::jsonb
)
RETURNING id::text`,
		input.TaskID,
		input.AttemptID,
		attemptNo,
		input.ModelType,
		input.PlatformID,
		input.PlatformModelID,
		input.ClientID,
		input.Changed,
		input.ChangeCount,
		string(actualInputJSON),
		string(convertedOutputJSON),
		string(changesJSON),
		string(modelSnapshotJSON),
	).Scan(&id)
	return id, err
}

func (s *Store) attachTaskAttempts(ctx context.Context, items []GatewayTask) ([]GatewayTask, error) {
	if len(items) == 0 {
		return items, nil
	}
	taskIDs := make([]string, 0, len(items))
	for _, item := range items {
		taskIDs = append(taskIDs, item.ID)
	}
	attemptsByTaskID, err := s.listTaskAttemptsByTaskIDs(ctx, taskIDs)
	if err != nil {
		return nil, err
	}
	for index := range items {
		items[index].Attempts = attemptsByTaskID[items[index].ID]
	}
	return items, nil
}

func (s *Store) ListTaskAttempts(ctx context.Context, taskID string) ([]TaskAttempt, error) {
	attemptsByTaskID, err := s.listTaskAttemptsByTaskIDs(ctx, []string{taskID})
	if err != nil {
		return nil, err
	}
	return attemptsByTaskID[taskID], nil
}

func (s *Store) ListTaskParamPreprocessingLogs(ctx context.Context, taskID string) ([]TaskParamPreprocessingLog, error) {
	rows, err := s.pool.Query(ctx, `
SELECT id::text, task_id::text, COALESCE(attempt_id::text, ''), COALESCE(attempt_no, 0),
       COALESCE(model_type, ''), COALESCE(platform_id::text, ''), COALESCE(platform_model_id::text, ''),
       COALESCE(client_id, ''), changed, change_count,
       COALESCE(actual_input, '{}'::jsonb), COALESCE(converted_output, '{}'::jsonb),
       COALESCE(changes, '[]'::jsonb), COALESCE(model_snapshot, '{}'::jsonb), created_at
FROM gateway_task_param_preprocessing_logs
WHERE task_id = $1::uuid
ORDER BY COALESCE(attempt_no, 0), created_at`, taskID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	items := make([]TaskParamPreprocessingLog, 0)
	for rows.Next() {
		item, err := scanTaskParamPreprocessingLog(rows)
		if err != nil {
			return nil, err
		}
		items = append(items, item)
	}
	return items, rows.Err()
}

func (s *Store) AppendTaskAttemptTrace(ctx context.Context, taskID string, attemptNo int, entry map[string]any) error {
	entryJSON, _ := json.Marshal(emptyObjectIfNil(entry))
	_, err := s.pool.Exec(ctx, `
UPDATE gateway_task_attempts
SET metrics = jsonb_set(
      COALESCE(metrics, '{}'::jsonb),
      '{trace}',
      (
        CASE
          WHEN jsonb_typeof(COALESCE(metrics->'trace', '[]'::jsonb)) = 'array'
          THEN COALESCE(metrics->'trace', '[]'::jsonb)
          ELSE '[]'::jsonb
        END
      ) || jsonb_build_array($3::jsonb),
      true
    )
WHERE task_id = $1::uuid
  AND attempt_no = $2::int`, taskID, attemptNo, string(entryJSON))
	return err
}

func (s *Store) listTaskAttemptsByTaskIDs(ctx context.Context, taskIDs []string) (map[string][]TaskAttempt, error) {
	itemsByTaskID := map[string][]TaskAttempt{}
	if len(taskIDs) == 0 {
		return itemsByTaskID, nil
	}
	rows, err := s.pool.Query(ctx, `
SELECT a.id::text, a.task_id::text, a.attempt_no,
       COALESCE(a.platform_id::text, ''), COALESCE(p.name, ''), COALESCE(p.provider, ''),
       COALESCE(a.platform_model_id::text, ''), COALESCE(pm.model_name, ''),
       COALESCE(NULLIF(pm.provider_model_name, ''), pm.model_name, ''),
       COALESCE(pm.model_alias, ''),
       COALESCE(a.client_id, ''), a.queue_key, a.status, a.retryable, a.simulated,
       COALESCE(a.request_id, ''), COALESCE(a.usage, '{}'::jsonb), COALESCE(a.metrics, '{}'::jsonb),
       a.request_snapshot, COALESCE(a.response_snapshot, '{}'::jsonb),
       COALESCE(a.response_started_at::text, ''), COALESCE(a.response_finished_at::text, ''),
       COALESCE(a.response_duration_ms, 0), COALESCE(a.error_code, ''), COALESCE(a.error_message, ''),
       COALESCE(a.pricing_snapshot, '{}'::jsonb), COALESCE(a.request_fingerprint, ''),
       a.upstream_submission_status, COALESCE(a.upstream_submission_updated_at::text, ''),
       a.started_at, COALESCE(a.finished_at::text, '')
FROM gateway_task_attempts a
LEFT JOIN integration_platforms p ON p.id = a.platform_id
LEFT JOIN platform_models pm ON pm.id = a.platform_model_id
WHERE a.task_id::text = ANY($1)
ORDER BY a.task_id, a.attempt_no`, taskIDs)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	for rows.Next() {
		item, err := scanTaskAttempt(rows)
		if err != nil {
			return nil, err
		}
		itemsByTaskID[item.TaskID] = append(itemsByTaskID[item.TaskID], item)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}
	return itemsByTaskID, nil
}

func scanTaskAttempt(scanner taskScanner) (TaskAttempt, error) {
	var item TaskAttempt
	var usageBytes []byte
	var metricsBytes []byte
	var requestBytes []byte
	var responseBytes []byte
	var pricingSnapshotBytes []byte
	if err := scanner.Scan(
		&item.ID,
		&item.TaskID,
		&item.AttemptNo,
		&item.PlatformID,
		&item.PlatformName,
		&item.Provider,
		&item.PlatformModelID,
		&item.ModelName,
		&item.ProviderModelName,
		&item.ModelAlias,
		&item.ClientID,
		&item.QueueKey,
		&item.Status,
		&item.Retryable,
		&item.Simulated,
		&item.RequestID,
		&usageBytes,
		&metricsBytes,
		&requestBytes,
		&responseBytes,
		&item.ResponseStartedAt,
		&item.ResponseFinishedAt,
		&item.ResponseDurationMS,
		&item.ErrorCode,
		&item.ErrorMessage,
		&pricingSnapshotBytes,
		&item.RequestFingerprint,
		&item.UpstreamSubmissionStatus,
		&item.UpstreamSubmissionUpdatedAt,
		&item.StartedAt,
		&item.FinishedAt,
	); err != nil {
		return TaskAttempt{}, err
	}
	item.Usage = decodeObject(usageBytes)
	item.Metrics = decodeObject(metricsBytes)
	item.RequestSnapshot = decodeObject(requestBytes)
	item.ResponseSnapshot = decodeObject(responseBytes)
	item.PricingSnapshot = decodeObject(pricingSnapshotBytes)
	enrichTaskAttemptFromMetrics(&item)
	return item, nil
}

func scanTaskParamPreprocessingLog(scanner taskScanner) (TaskParamPreprocessingLog, error) {
	var item TaskParamPreprocessingLog
	var actualInputBytes []byte
	var convertedOutputBytes []byte
	var changesBytes []byte
	var modelSnapshotBytes []byte
	if err := scanner.Scan(
		&item.ID,
		&item.TaskID,
		&item.AttemptID,
		&item.AttemptNo,
		&item.ModelType,
		&item.PlatformID,
		&item.PlatformModelID,
		&item.ClientID,
		&item.Changed,
		&item.ChangeCount,
		&actualInputBytes,
		&convertedOutputBytes,
		&changesBytes,
		&modelSnapshotBytes,
		&item.CreatedAt,
	); err != nil {
		return TaskParamPreprocessingLog{}, err
	}
	item.ActualInput = decodeObject(actualInputBytes)
	item.ConvertedOutput = decodeObject(convertedOutputBytes)
	item.Changes = decodeArray(changesBytes)
	item.ModelSnapshot = decodeObject(modelSnapshotBytes)
	return item, nil
}

func enrichTaskAttemptFromMetrics(item *TaskAttempt) {
	if item == nil || len(item.Metrics) == 0 {
		return
	}
	item.PlatformID = firstNonEmpty(item.PlatformID, taskAttemptMetricString(item.Metrics, "platformId"))
	item.PlatformName = firstNonEmpty(item.PlatformName, taskAttemptMetricString(item.Metrics, "platformName"))
	item.Provider = firstNonEmpty(item.Provider, taskAttemptMetricString(item.Metrics, "provider"))
	item.PlatformModelID = firstNonEmpty(item.PlatformModelID, taskAttemptMetricString(item.Metrics, "platformModelId"))
	item.ModelName = firstNonEmpty(item.ModelName, taskAttemptMetricString(item.Metrics, "resolvedModel"), taskAttemptMetricString(item.Metrics, "modelName"))
	item.ProviderModelName = firstNonEmpty(item.ProviderModelName, taskAttemptMetricString(item.Metrics, "providerModel"))
	item.ModelAlias = firstNonEmpty(item.ModelAlias, taskAttemptMetricString(item.Metrics, "modelAlias"))
	item.ModelType = firstNonEmpty(item.ModelType, taskAttemptMetricString(item.Metrics, "modelType"))
	item.ClientID = firstNonEmpty(item.ClientID, taskAttemptMetricString(item.Metrics, "clientId"))
	item.StatusCode = taskAttemptMetricInt(item.Metrics, "statusCode")
}

func taskAttemptMetricString(metrics map[string]any, key string) string {
	value, _ := metrics[key].(string)
	return strings.TrimSpace(value)
}

func taskAttemptMetricInt(metrics map[string]any, key string) int {
	switch value := metrics[key].(type) {
	case int:
		return value
	case int64:
		return int(value)
	case float64:
		return int(value)
	case json.Number:
		next, _ := value.Int64()
		return int(next)
	case string:
		next, _ := strconv.Atoi(strings.TrimSpace(value))
		return next
	default:
		return 0
	}
}

func (s *Store) FinishTaskAttempt(ctx context.Context, input FinishTaskAttemptInput) error {
	responseJSON, _ := json.Marshal(emptyObjectIfNil(input.ResponseSnapshot))
	usageJSON, _ := json.Marshal(emptyObjectIfNil(input.Usage))
	metricsJSON, _ := json.Marshal(emptyObjectIfNil(input.Metrics))
	_, err := s.pool.Exec(ctx, `
UPDATE gateway_task_attempts
SET status = $2::text,
    retryable = $3,
    request_id = NULLIF($4::text, ''),
    usage = $5::jsonb,
    metrics = $6::jsonb,
    response_snapshot = $7::jsonb,
    response_started_at = $8::timestamptz,
    response_finished_at = $9::timestamptz,
    response_duration_ms = $10,
    error_code = NULLIF($11::text, ''),
    error_message = NULLIF($12::text, ''),
    finished_at = now()
WHERE id = $1::uuid`,
		input.AttemptID,
		input.Status,
		input.Retryable,
		input.RequestID,
		string(usageJSON),
		string(metricsJSON),
		string(responseJSON),
		nullableTime(input.ResponseStartedAt),
		nullableTime(input.ResponseFinishedAt),
		input.ResponseDurationMS,
		input.ErrorCode,
		input.ErrorMessage,
	)
	return err
}

func (s *Store) FinishTaskSuccess(ctx context.Context, input FinishTaskSuccessInput) (GatewayTask, error) {
	resultJSON, _ := json.Marshal(emptyObjectIfNil(input.Result))
	billingsJSON, _ := json.Marshal(input.Billings)
	usageJSON, _ := json.Marshal(emptyObjectIfNil(input.Usage))
	metricsJSON, _ := json.Marshal(emptyObjectIfNil(input.Metrics))
	billingSummaryJSON, _ := json.Marshal(emptyObjectIfNil(input.BillingSummary))
	pricingSnapshotJSON, _ := json.Marshal(emptyObjectIfNil(input.PricingSnapshot))
	finalChargeAmount := strings.TrimSpace(input.FinalChargeAmountText)
	if finalChargeAmount == "" {
		finalChargeAmount = strconv.FormatFloat(input.FinalChargeAmount, 'f', 9, 64)
	}
	currency := normalizeWalletCurrency(input.BillingCurrency)
	err := pgx.BeginFunc(ctx, s.pool, func(tx pgx.Tx) error {
		if strings.TrimSpace(input.AttemptID) != "" {
			if _, err := tx.Exec(ctx, `
UPDATE gateway_task_attempts
SET status = 'succeeded',
    retryable = false,
    request_id = NULLIF($2, ''),
    usage = $3::jsonb,
    metrics = $4::jsonb,
    response_snapshot = $5::jsonb,
    pricing_snapshot = $6::jsonb,
    request_fingerprint = NULLIF($7, ''),
    upstream_submission_status = 'response_received',
    upstream_submission_updated_at = now(),
    response_started_at = $8::timestamptz,
    response_finished_at = $9::timestamptz,
    response_duration_ms = $10,
    error_code = NULL,
    error_message = NULL,
    finished_at = now()
WHERE id = $1::uuid`,
				input.AttemptID, input.RequestID, string(usageJSON), string(metricsJSON),
				string(resultJSON), string(pricingSnapshotJSON), input.RequestFingerprint,
				nullableTime(input.ResponseStartedAt), nullableTime(input.ResponseFinishedAt), input.ResponseDurationMS,
			); err != nil {
				return err
			}
		}
		tag, err := tx.Exec(ctx, `
UPDATE gateway_tasks
SET status = 'succeeded',
    result = $2::jsonb,
    billings = $3::jsonb,
    request_id = NULLIF($4, ''),
    resolved_model = NULLIF($5, ''),
    usage = $6::jsonb,
    metrics = $7::jsonb,
    billing_summary = $8::jsonb,
    final_charge_amount = $9::numeric,
    billing_version = 'effective-pricing-v2',
    billing_status = CASE
      WHEN run_mode = 'production' AND gateway_user_id IS NOT NULL THEN 'pending'
      ELSE 'not_required'
    END,
    billing_currency = $10,
    pricing_snapshot = $11::jsonb,
    request_fingerprint = NULLIF($12, ''),
    billing_updated_at = now(),
    response_started_at = $13::timestamptz,
    response_finished_at = $14::timestamptz,
    response_duration_ms = $15,
    error = NULL,
    error_code = NULL,
    error_message = NULL,
    locked_by = NULL,
    locked_at = NULL,
    heartbeat_at = NULL,
    execution_token = NULL,
    execution_lease_expires_at = NULL,
    finished_at = now(),
    updated_at = now()
WHERE id = $1::uuid
  AND status = 'running'
  AND execution_token = $16::uuid`,
			input.TaskID,
			string(resultJSON),
			string(billingsJSON),
			input.RequestID,
			input.ResolvedModel,
			string(usageJSON),
			string(metricsJSON),
			string(billingSummaryJSON),
			finalChargeAmount,
			currency,
			string(pricingSnapshotJSON),
			input.RequestFingerprint,
			nullableTime(input.ResponseStartedAt),
			nullableTime(input.ResponseFinishedAt),
			input.ResponseDurationMS,
			input.ExecutionToken,
		)
		if err != nil {
			return err
		}
		if tag.RowsAffected() != 1 {
			return ErrTaskExecutionLeaseLost
		}
		payloadJSON, _ := json.Marshal(map[string]any{"taskId": input.TaskID, "pricingVersion": "effective-pricing-v2"})
		_, err = tx.Exec(ctx, `
INSERT INTO settlement_outbox (
  task_id, event_type, action, amount, currency, pricing_snapshot, payload, status, next_attempt_at
)
SELECT id, 'task.billing.settle', 'settle', $2::numeric, $3, $4::jsonb, $5::jsonb, 'pending', now()
FROM gateway_tasks
WHERE id = $1::uuid
  AND run_mode = 'production'
  AND gateway_user_id IS NOT NULL
ON CONFLICT (task_id, event_type) DO NOTHING`,
			input.TaskID, finalChargeAmount, currency, string(pricingSnapshotJSON), string(payloadJSON))
		return err
	})
	if err != nil {
		return GatewayTask{}, err
	}
	return s.GetTask(ctx, input.TaskID)
}

func (s *Store) FinishTaskManualReview(ctx context.Context, input FinishTaskManualReviewInput) (GatewayTask, error) {
	status := strings.TrimSpace(input.TaskStatus)
	if status != "succeeded" && status != "failed" {
		return GatewayTask{}, fmt.Errorf("manual review task status must be succeeded or failed")
	}
	resultJSON, _ := json.Marshal(emptyObjectIfNil(input.Result))
	pricingSnapshotJSON, _ := json.Marshal(emptyObjectIfNil(input.PricingSnapshot))
	err := pgx.BeginFunc(ctx, s.pool, func(tx pgx.Tx) error {
		if strings.TrimSpace(input.AttemptID) != "" {
			attemptStatus := "failed"
			if status == "succeeded" {
				attemptStatus = "succeeded"
			}
			if _, err := tx.Exec(ctx, `
UPDATE gateway_task_attempts
SET status = $2,
    request_id = NULLIF($3, ''),
    error_code = CASE WHEN $2 = 'failed' THEN NULLIF($4, '') ELSE NULL END,
    error_message = CASE WHEN $2 = 'failed' THEN NULLIF($5, '') ELSE NULL END,
    upstream_submission_status = CASE WHEN $2 = 'succeeded' THEN 'response_received' ELSE upstream_submission_status END,
    upstream_submission_updated_at = now(),
    response_started_at = $6::timestamptz,
    response_finished_at = $7::timestamptz,
    response_duration_ms = $8,
    finished_at = now()
WHERE id = $1::uuid`, input.AttemptID, attemptStatus, input.RequestID, input.Code, input.Message,
				nullableTime(input.ResponseStartedAt), nullableTime(input.ResponseFinishedAt), input.ResponseDurationMS); err != nil {
				return err
			}
		}
		tag, err := tx.Exec(ctx, `
UPDATE gateway_tasks
SET status = $2,
    result = $3::jsonb,
    request_id = NULLIF($4, ''),
    error = CASE WHEN $2 = 'failed' THEN NULLIF($6, '') ELSE NULL END,
    error_code = NULLIF($5, ''),
    error_message = NULLIF($6, ''),
    billing_status = 'manual_review',
    pricing_snapshot = CASE WHEN $7::jsonb = '{}'::jsonb THEN pricing_snapshot ELSE $7::jsonb END,
    request_fingerprint = COALESCE(NULLIF($8, ''), request_fingerprint),
    billing_updated_at = now(),
    response_started_at = $9::timestamptz,
    response_finished_at = $10::timestamptz,
    response_duration_ms = $11,
    locked_by = NULL,
    locked_at = NULL,
    heartbeat_at = NULL,
    execution_token = NULL,
    execution_lease_expires_at = NULL,
    finished_at = now(),
    updated_at = now()
WHERE id = $1::uuid
  AND status = 'running'
  AND execution_token = $12::uuid`, input.TaskID, status, string(resultJSON), input.RequestID, input.Code, input.Message,
			string(pricingSnapshotJSON), input.RequestFingerprint, nullableTime(input.ResponseStartedAt),
			nullableTime(input.ResponseFinishedAt), input.ResponseDurationMS, input.ExecutionToken)
		if err != nil {
			return err
		}
		if tag.RowsAffected() != 1 {
			return ErrTaskExecutionLeaseLost
		}
		payloadJSON, _ := json.Marshal(map[string]any{
			"taskId": input.TaskID, "classification": input.Code,
		})
		_, err = tx.Exec(ctx, `
INSERT INTO settlement_outbox (
  task_id, event_type, action, amount, currency, pricing_snapshot, payload,
  status, next_attempt_at, manual_review_reason
)
SELECT id, 'task.billing.review', 'release', reservation_amount, billing_currency,
       pricing_snapshot, $2::jsonb, 'manual_review', now(), $3
FROM gateway_tasks
WHERE id = $1::uuid
  AND run_mode = 'production'
  AND gateway_user_id IS NOT NULL
ON CONFLICT (task_id, event_type) DO NOTHING`, input.TaskID, string(payloadJSON), input.Code)
		return err
	})
	if err != nil {
		return GatewayTask{}, err
	}
	return s.GetTask(ctx, input.TaskID)
}

func (s *Store) SettleTaskBilling(ctx context.Context, task GatewayTask) error {
	if task.FinalChargeAmount <= 0 || strings.TrimSpace(task.GatewayUserID) == "" {
		return nil
	}
	currency := strings.TrimSpace(taskBillingString(task.BillingSummary["currency"]))
	if currency == "" || currency == "mixed" {
		currency = "resource"
	}
	modelIdentity := taskBillingModelIdentity(task)
	metadataMap := map[string]any{
		"taskId":         task.ID,
		"kind":           task.Kind,
		"model":          modelIdentity.Model,
		"requestedModel": modelIdentity.RequestedModel,
		"resolvedModel":  modelIdentity.ResolvedModel,
		"modelName":      modelIdentity.ModelName,
		"modelAlias":     modelIdentity.ModelAlias,
		"providerModel":  modelIdentity.ProviderModelName,
		"billings":       task.Billings,
		"billingSummary": task.BillingSummary,
	}
	metadata, _ := json.Marshal(metadataMap)
	return pgx.BeginFunc(ctx, s.pool, func(tx pgx.Tx) error {
		if _, err := tx.Exec(ctx, `
INSERT INTO gateway_wallet_accounts (
  gateway_tenant_id, gateway_user_id, tenant_id, tenant_key, user_id, currency
)
VALUES (NULLIF($1, '')::uuid, $2::uuid, NULLIF($3, ''), NULLIF($4, ''), NULLIF($5, ''), $6)
ON CONFLICT (gateway_user_id, currency) DO NOTHING`,
			task.GatewayTenantID, task.GatewayUserID, task.TenantID, task.TenantKey, task.UserID, currency); err != nil {
			return err
		}
		if err := ensureWalletAccountAuditGuard(ctx, tx, task.GatewayUserID, currency); err != nil {
			return err
		}
		var exists bool
		var accountID string
		var balanceBefore float64
		var frozenBefore float64
		var gatewayTenantID string
		if err := tx.QueryRow(ctx, `
SELECT id::text, balance::float8, frozen_balance::float8, COALESCE(gateway_tenant_id::text, '')
FROM gateway_wallet_accounts
WHERE gateway_user_id = $1::uuid
  AND currency = $2
FOR UPDATE`, task.GatewayUserID, currency).Scan(&accountID, &balanceBefore, &frozenBefore, &gatewayTenantID); err != nil {
			return err
		}
		if err := tx.QueryRow(ctx, `
SELECT EXISTS (
  SELECT 1
  FROM gateway_wallet_transactions
  WHERE account_id = $1::uuid
    AND idempotency_key = $2
)`, accountID, billingIdempotencyKey(task.ID)).Scan(&exists); err != nil {
			return err
		}
		if exists {
			return nil
		}

		amount := roundMoney(task.FinalChargeAmount)
		reservationKey, reservedAmount, err := activeWalletReservation(ctx, tx, accountID, task.ID)
		if err != nil {
			return err
		}
		reservedAmount = roundMoney(reservedAmount)
		spendableForTask := roundMoney(balanceBefore - frozenBefore + reservedAmount)
		if spendableForTask+0.000001 < amount {
			return fmt.Errorf("%w: required %.6f %s, available %.6f", ErrInsufficientWalletBalance, amount, currency, spendableForTask)
		}

		balanceAfter := roundMoney(balanceBefore - amount)
		frozenAfter := roundMoney(frozenBefore - reservedAmount)
		if frozenAfter < 0 {
			frozenAfter = 0
		}
		if _, err := tx.Exec(ctx, `
UPDATE gateway_wallet_accounts
SET balance = $2,
    total_spent = total_spent + $3,
    frozen_balance = $4,
    updated_at = now()
WHERE id = $1::uuid`, accountID, balanceAfter, amount, frozenAfter); err != nil {
			return err
		}
		if reservedAmount > 0 {
			releaseMetadata, _ := json.Marshal(map[string]any{
				"taskId":       task.ID,
				"reason":       "task_billing_settled",
				"reserved":     reservedAmount,
				"frozenBefore": roundMoney(frozenBefore),
				"frozenAfter":  frozenAfter,
			})
			if _, err := tx.Exec(ctx, `
INSERT INTO gateway_wallet_transactions (
  account_id, gateway_tenant_id, gateway_user_id, direction, transaction_type,
  amount, balance_before, balance_after, idempotency_key, reference_type, reference_id, metadata
)
VALUES (
  $1::uuid, NULLIF($2, '')::uuid, $3::uuid, 'credit', 'release',
  $4, $5, $6, $7, 'gateway_task', $8, $9::jsonb
)
ON CONFLICT (account_id, idempotency_key) WHERE idempotency_key IS NOT NULL DO NOTHING`,
				accountID, firstNonEmpty(gatewayTenantID, task.GatewayTenantID), task.GatewayUserID, reservedAmount, roundMoney(balanceBefore), roundMoney(balanceBefore), billingReservationReleaseIdempotencyKey(reservationKey), task.ID, string(releaseMetadata)); err != nil {
				return err
			}
		}
		billingMetadata := mergeObjects(metadataMap, map[string]any{
			"reservedAmount": reservedAmount,
			"frozenBefore":   roundMoney(frozenBefore),
			"frozenAfter":    frozenAfter,
		})
		metadata, _ = json.Marshal(billingMetadata)
		if _, err := tx.Exec(ctx, `
INSERT INTO gateway_wallet_transactions (
  account_id, gateway_tenant_id, gateway_user_id, direction, transaction_type,
  amount, balance_before, balance_after, idempotency_key, reference_type, reference_id, metadata
)
VALUES (
  $1::uuid, NULLIF($2, '')::uuid, $3::uuid, 'debit', 'task_billing',
  $4, $5, $6, $7, 'gateway_task', $8, $9::jsonb
)`,
			accountID, firstNonEmpty(gatewayTenantID, task.GatewayTenantID), task.GatewayUserID, amount, roundMoney(balanceBefore), balanceAfter, billingIdempotencyKey(task.ID), task.ID, string(metadata)); err != nil {
			return err
		}
		return nil
	})
}

func billingIdempotencyKey(taskID string) string {
	return "task:" + taskID + ":billing"
}

func roundMoney(value float64) float64 {
	if value < 0 {
		return -roundMoney(-value)
	}
	return float64(int64(value*1000000+0.5)) / 1000000
}

func taskBillingString(value any) string {
	if text, ok := value.(string); ok {
		return strings.TrimSpace(text)
	}
	return ""
}

func (s *Store) FinishTaskFailure(ctx context.Context, input FinishTaskFailureInput) (GatewayTask, error) {
	metricsJSON, _ := json.Marshal(emptyObjectIfNil(input.Metrics))
	resultJSON, _ := json.Marshal(emptyObjectIfNil(input.Result))
	err := pgx.BeginFunc(ctx, s.pool, func(tx pgx.Tx) error {
		tag, err := tx.Exec(ctx, `
	UPDATE gateway_tasks
	SET status = 'failed',
	    error = NULLIF($2::text, ''),
	    error_code = NULLIF($3::text, ''),
	    error_message = NULLIF($2::text, ''),
	    request_id = NULLIF($4::text, ''),
	    metrics = $5::jsonb,
	    response_started_at = $6::timestamptz,
	    response_finished_at = $7::timestamptz,
	    response_duration_ms = $8,
	    result = $9::jsonb,
	    billing_status = CASE
	      WHEN run_mode <> 'production' OR gateway_user_id IS NULL THEN 'not_required'
	      WHEN reservation_amount > 0 THEN 'pending'
	      ELSE 'released'
	    END,
	    billing_updated_at = now(),
	    locked_by = NULL,
	    locked_at = NULL,
	    heartbeat_at = NULL,
	    execution_token = NULL,
	    execution_lease_expires_at = NULL,
	    finished_at = now(),
	    updated_at = now()
WHERE id = $1::uuid
  AND status = 'running'
  AND execution_token = $10::uuid`,
			input.TaskID,
			input.Message,
			input.Code,
			input.RequestID,
			string(metricsJSON),
			nullableTime(input.ResponseStartedAt),
			nullableTime(input.ResponseFinishedAt),
			input.ResponseDurationMS,
			string(resultJSON),
			input.ExecutionToken,
		)
		if err != nil {
			return err
		}
		if tag.RowsAffected() != 1 {
			return ErrTaskExecutionLeaseLost
		}
		payloadJSON, _ := json.Marshal(map[string]any{"taskId": input.TaskID, "reason": input.Code})
		_, err = tx.Exec(ctx, `
INSERT INTO settlement_outbox (
  task_id, event_type, action, amount, currency, pricing_snapshot, payload, status, next_attempt_at
)
SELECT id, 'task.billing.release', 'release', reservation_amount, billing_currency,
       pricing_snapshot, $2::jsonb, 'pending', now()
FROM gateway_tasks
WHERE id = $1::uuid
  AND run_mode = 'production'
  AND gateway_user_id IS NOT NULL
  AND reservation_amount > 0
ON CONFLICT (task_id, event_type) DO NOTHING`, input.TaskID, string(payloadJSON))
		return err
	})
	if err != nil {
		return GatewayTask{}, err
	}
	return s.GetTask(ctx, input.TaskID)
}

func nullableTime(value time.Time) any {
	if value.IsZero() {
		return nil
	}
	return value
}

func (s *Store) AddTaskEvent(ctx context.Context, taskID string, eventType string, status string, phase string, progress float64, message string, payload map[string]any, simulated bool) (TaskEvent, error) {
	payloadJSON, _ := json.Marshal(emptyObjectIfNil(payload))
	var event TaskEvent
	var payloadBytes []byte
	err := s.pool.QueryRow(ctx, `
WITH next_seq AS (
  SELECT COALESCE(MAX(seq), 0) + 1 AS seq
  FROM gateway_task_events
  WHERE task_id = $1::uuid
)
INSERT INTO gateway_task_events (task_id, seq, event_type, status, phase, progress, message, payload, simulated)
SELECT $1::uuid, next_seq.seq, $2::text, NULLIF($3::text, ''), NULLIF($4::text, ''), $5, NULLIF($6::text, ''), $7::jsonb, $8
FROM next_seq
RETURNING id::text, task_id::text, seq, event_type, COALESCE(status, ''), COALESCE(phase, ''),
          COALESCE(progress, 0)::float8, COALESCE(message, ''), payload, simulated, created_at`,
		taskID,
		eventType,
		status,
		phase,
		progress,
		message,
		string(payloadJSON),
		simulated,
	).Scan(
		&event.ID,
		&event.TaskID,
		&event.Seq,
		&event.EventType,
		&event.Status,
		&event.Phase,
		&event.Progress,
		&event.Message,
		&payloadBytes,
		&event.Simulated,
		&event.CreatedAt,
	)
	if err != nil {
		return TaskEvent{}, err
	}
	event.Payload = decodeObject(payloadBytes)
	return event, nil
}

func (s *Store) QueueTaskCallback(ctx context.Context, event TaskEvent, callbackURL string) error {
	if callbackURL == "" {
		return nil
	}
	payloadJSON, _ := json.Marshal(map[string]any{
		"taskId":    event.TaskID,
		"seq":       event.Seq,
		"eventType": event.EventType,
		"status":    event.Status,
		"phase":     event.Phase,
		"progress":  event.Progress,
		"message":   event.Message,
		"payload":   event.Payload,
		"simulated": event.Simulated,
		"createdAt": event.CreatedAt,
	})
	_, err := s.pool.Exec(ctx, `
INSERT INTO gateway_task_callback_outbox (task_id, event_id, seq, callback_url, payload)
VALUES ($1::uuid, $2::uuid, $3, $4, $5::jsonb)
ON CONFLICT (task_id, seq, callback_url) DO NOTHING`,
		event.TaskID,
		event.ID,
		event.Seq,
		callbackURL,
		string(payloadJSON),
	)
	return err
}

func (s *Store) RecordClientAssignment(ctx context.Context, candidate RuntimeModelCandidate) error {
	_, err := s.pool.Exec(ctx, `
INSERT INTO runtime_client_states (
  client_id, platform_id, provider, method_name, queue_key, running_count, last_assigned_at
)
VALUES ($1, $2::uuid, $3, $4, $5, 1, now())
ON CONFLICT (client_id) DO UPDATE
SET running_count = runtime_client_states.running_count + 1,
    last_assigned_at = now(),
    updated_at = now()`,
		candidate.ClientID,
		candidate.PlatformID,
		candidate.Provider,
		candidate.ModelType,
		candidate.QueueKey,
	)
	return err
}

func (s *Store) RecordClientRelease(ctx context.Context, clientID string, lastError string) error {
	_, err := s.pool.Exec(ctx, `
UPDATE runtime_client_states
SET running_count = GREATEST(running_count - 1, 0),
    last_error = NULLIF($2::text, ''),
    updated_at = now()
WHERE client_id = $1`, clientID, lastError)
	return err
}