package runner

import (
	"context"
	"errors"
	"log/slog"
	"strconv"
	"strings"
	"time"

	"github.com/easyai/easyai-ai-gateway/apps/api/internal/auth"
	"github.com/easyai/easyai-ai-gateway/apps/api/internal/clients"
	"github.com/easyai/easyai-ai-gateway/apps/api/internal/config"
	"github.com/easyai/easyai-ai-gateway/apps/api/internal/store"
)

type Service struct {
	cfg         config.Config
	store       *store.Store
	logger      *slog.Logger
	clients     map[string]clients.Client
	httpClients *httpClientCache
}

type Result struct {
	Task   store.GatewayTask
	Output map[string]any
}

func New(cfg config.Config, db *store.Store, logger *slog.Logger) *Service {
	httpClients := newHTTPClientCache()
	return &Service{
		cfg:    cfg,
		store:  db,
		logger: logger,
		clients: map[string]clients.Client{
			"openai":     clients.OpenAIClient{HTTPClient: httpClients.none},
			"gemini":     clients.GeminiClient{HTTPClient: httpClients.none},
			"volces":     clients.VolcesClient{HTTPClient: httpClients.none},
			"simulation": clients.SimulationClient{},
		},
		httpClients: httpClients,
	}
}

func (s *Service) Execute(ctx context.Context, task store.GatewayTask, user *auth.User) (Result, error) {
	return s.execute(ctx, task, user, nil)
}

func (s *Service) ExecuteStream(ctx context.Context, task store.GatewayTask, user *auth.User, onDelta clients.StreamDelta) (Result, error) {
	return s.execute(ctx, task, user, onDelta)
}

func (s *Service) execute(ctx context.Context, task store.GatewayTask, user *auth.User, onDelta clients.StreamDelta) (Result, error) {
	executeStartedAt := time.Now()
	body := normalizeRequest(task.Kind, task.Request)
	modelType := modelTypeFromKind(task.Kind, body)
	if err := validateRequest(task.Kind, body); err != nil {
		failed, finishErr := s.failTask(ctx, task.ID, "bad_request", err.Error(), task.RunMode == "simulation", err)
		if finishErr != nil {
			return Result{}, finishErr
		}
		return Result{Task: failed, Output: failed.Result}, err
	}
	candidates, err := s.store.ListModelCandidates(ctx, task.Model, modelType, user)
	if err != nil {
		failed, finishErr := s.failTask(ctx, task.ID, store.ModelCandidateErrorCode(err), err.Error(), task.RunMode == "simulation", err)
		if finishErr != nil {
			return Result{}, finishErr
		}
		return Result{Task: failed, Output: failed.Result}, err
	}
	if len(candidates) > 0 {
		estimatedBillings := s.estimatedBillings(ctx, user, task.Kind, body, candidates[0])
		if err := s.ensureWalletBalance(ctx, user, estimatedBillings); err != nil {
			if errors.Is(err, store.ErrInsufficientWalletBalance) {
				failed, finishErr := s.failTask(ctx, task.ID, "insufficient_balance", err.Error(), task.RunMode == "simulation", err)
				if finishErr != nil {
					return Result{}, finishErr
				}
				return Result{Task: failed, Output: failed.Result}, err
			}
			return Result{}, err
		}
	}
	if err := s.store.MarkTaskRunning(ctx, task.ID, modelType, body); err != nil {
		return Result{}, err
	}
	if err := s.emit(ctx, task.ID, "task.progress", "running", "normalizing", 0.15, "request normalized", map[string]any{"modelType": modelType}, task.RunMode == "simulation"); err != nil {
		return Result{}, err
	}

	runnerPolicy, err := s.store.GetActiveRunnerPolicy(ctx)
	if err != nil {
		return Result{}, err
	}
	maxPlatforms := maxPlatformsForCandidates(candidates, runnerPolicy)
	maxFailoverDuration := maxFailoverDurationForCandidates(candidates, runnerPolicy)
	attemptNo := 0
	var lastErr error
	for index, candidate := range candidates {
		if index >= maxPlatforms {
			break
		}
		clientAttempts := clientAttemptsForCandidate(candidate)
		var candidateErr error
		for clientAttempt := 1; clientAttempt <= clientAttempts; clientAttempt++ {
			attemptNo++
			response, err := s.runCandidate(ctx, task, user, body, candidate, attemptNo, onDelta)
			if err == nil {
				billings := s.billings(ctx, user, task.Kind, body, candidate, response, isSimulation(task, candidate))
				record := buildSuccessRecord(task, user, body, candidate, response, billings, isSimulation(task, candidate))
				record.Metrics = s.withAttemptHistory(ctx, task.ID, record.Metrics)
				finished, finishErr := s.store.FinishTaskSuccess(ctx, store.FinishTaskSuccessInput{
					TaskID:             task.ID,
					Result:             response.Result,
					Billings:           billings,
					RequestID:          record.RequestID,
					ResolvedModel:      record.ResolvedModel,
					Usage:              record.Usage,
					Metrics:            record.Metrics,
					BillingSummary:     record.BillingSummary,
					FinalChargeAmount:  record.FinalChargeAmount,
					ResponseStartedAt:  record.ResponseStartedAt,
					ResponseFinishedAt: record.ResponseFinishedAt,
					ResponseDurationMS: record.ResponseDurationMS,
				})
				if finishErr != nil {
					return Result{}, finishErr
				}
				if settleErr := s.store.SettleTaskBilling(ctx, finished); settleErr != nil {
					return Result{}, settleErr
				}
				if finished.FinalChargeAmount > 0 {
					if err := s.emit(ctx, task.ID, "task.billing.settled", "succeeded", "billing", 0.98, "task billing settled", map[string]any{
						"amount":   finished.FinalChargeAmount,
						"currency": stringFromAny(record.BillingSummary["currency"]),
					}, isSimulation(task, candidate)); err != nil {
						return Result{}, err
					}
				}
				if err := s.emit(ctx, task.ID, "task.completed", "succeeded", "completed", 1, "task completed", map[string]any{
					"result":         response.Result,
					"billings":       billings,
					"usage":          record.Usage,
					"metrics":        record.Metrics,
					"billingSummary": record.BillingSummary,
					"requestId":      record.RequestID,
				}, isSimulation(task, candidate)); err != nil {
					return Result{}, err
				}
				return Result{Task: finished, Output: response.Result}, nil
			}
			lastErr = err
			candidateErr = err
			retryDecision := retryDecisionForCandidate(candidate, err)
			retryAction := "retry"
			if !retryDecision.Retry {
				retryAction = "stop"
			}
			if clientAttempt >= clientAttempts {
				retryDecision.Retry = false
				retryDecision.Reason = "same_client_max_attempts"
				retryDecision.Match = policyRuleMatch{
					Source: "model_runtime_policy_sets.retry_policy",
					Policy: "retryPolicy",
					Rule:   "maxAttempts",
					Value:  strconv.Itoa(clientAttempts),
				}
				retryDecision.Info = failureInfoFromError(err)
				retryAction = "stop"
			}
			if failoverTimeBudgetExceeded(executeStartedAt, maxFailoverDuration) {
				retryDecision.Retry = false
				retryDecision.Reason = "failover_time_budget_exceeded"
				retryDecision.Match = policyRuleMatch{
					Source: "gateway_runner_policies.failover_policy",
					Policy: "failoverPolicy",
					Rule:   "maxDurationSeconds",
					Value:  strconv.Itoa(int(maxFailoverDuration.Seconds())),
				}
				retryDecision.Info = failureInfoFromError(err)
				retryAction = "stop"
			}
			s.recordAttemptTrace(ctx, task.ID, attemptNo, retryTraceEntry(retryDecision, retryAction, clientAttempt, clientAttempts))
			if !retryDecision.Retry {
				break
			}
			if err := s.emit(ctx, task.ID, "task.retrying", "running", "retry", 0.45, "retrying same client", addPolicyTracePayload(map[string]any{
				"attempt":       attemptNo,
				"clientAttempt": clientAttempt,
				"clientId":      candidate.ClientID,
				"error":         err.Error(),
				"reason":        retryDecision.Reason,
				"scope":         "same_client",
			}, retryDecision.Match, retryDecision.Info), isSimulation(task, candidate)); err != nil {
				return Result{}, err
			}
		}
		if candidateErr == nil || index+1 >= len(candidates) || index+1 >= maxPlatforms {
			if candidateErr != nil {
				s.applyPriorityDemotePolicy(ctx, task.ID, attemptNo, runnerPolicy, candidate, candidateErr, isSimulation(task, candidate))
				decision := failoverDecisionForCandidate(runnerPolicy, candidate, candidateErr)
				if decision.Retry {
					decision.Retry = false
					decision.Action = "stop"
					decision.Reason = "no_next_platform"
					decision.Match = policyRuleMatch{Source: "runner_candidates", Policy: "candidateSelection", Rule: "candidateCount", Value: strconv.Itoa(len(candidates))}
					if index+1 >= maxPlatforms {
						decision.Reason = "max_platforms_reached"
						decision.Match = policyRuleMatch{Source: "gateway_runner_policies.failover_policy", Policy: "failoverPolicy", Rule: "maxPlatforms", Value: strconv.Itoa(maxPlatforms)}
					}
				}
				s.recordAttemptTrace(ctx, task.ID, attemptNo, failoverTraceEntry(decision))
			}
			break
		}
		s.applyPriorityDemotePolicy(ctx, task.ID, attemptNo, runnerPolicy, candidate, candidateErr, isSimulation(task, candidate))
		if failoverTimeBudgetExceeded(executeStartedAt, maxFailoverDuration) {
			elapsedSeconds := int(time.Since(executeStartedAt).Seconds())
			maxDurationSeconds := int(maxFailoverDuration.Seconds())
			s.recordAttemptTrace(ctx, task.ID, attemptNo, failoverTimeBudgetTraceEntry(elapsedSeconds, maxDurationSeconds, failureInfoFromError(candidateErr)))
			if err := s.emit(ctx, task.ID, "task.failover.stopped", "running", "retry", 0.55, "failover time budget exceeded", map[string]any{
				"elapsedSeconds":     elapsedSeconds,
				"maxDurationSeconds": maxDurationSeconds,
				"scope":              "next_platform",
				"statusCode":         clients.ErrorResponseMetadata(candidateErr).StatusCode,
			}, isSimulation(task, candidate)); err != nil {
				return Result{}, err
			}
			break
		}
		decision := failoverDecisionForCandidate(runnerPolicy, candidate, candidateErr)
		s.recordAttemptTrace(ctx, task.ID, attemptNo, failoverTraceEntry(decision))
		if !decision.Retry {
			break
		}
		s.applyFailoverAction(ctx, task.ID, candidate, decision, isSimulation(task, candidate))
		if err := s.emit(ctx, task.ID, "task.retrying", "running", "retry", 0.55, "retrying next client", addPolicyTracePayload(map[string]any{
			"attempt": attemptNo,
			"action":  decision.Action,
			"error":   candidateErr.Error(),
			"reason":  decision.Reason,
			"scope":   "next_platform",
		}, decision.Match, decision.Info), isSimulation(task, candidate)); err != nil {
			return Result{}, err
		}
	}
	code := clients.ErrorCode(lastErr)
	message := "task failed"
	if lastErr != nil {
		message = lastErr.Error()
	}
	failed, err := s.failTask(ctx, task.ID, code, message, task.RunMode == "simulation", lastErr)
	if err != nil {
		return Result{}, err
	}
	return Result{Task: failed, Output: failed.Result}, lastErr
}

func (s *Service) runCandidate(ctx context.Context, task store.GatewayTask, user *auth.User, body map[string]any, candidate store.RuntimeModelCandidate, attemptNo int, onDelta clients.StreamDelta) (clients.Response, error) {
	simulated := isSimulation(task, candidate)
	if err := s.emit(ctx, task.ID, "task.attempt.started", "running", "submitting", 0.25, "client attempt started", map[string]any{"attempt": attemptNo, "clientId": candidate.ClientID}, simulated); err != nil {
		return clients.Response{}, err
	}
	attemptID, err := s.store.CreateTaskAttempt(ctx, store.CreateTaskAttemptInput{
		TaskID:          task.ID,
		AttemptNo:       attemptNo,
		PlatformID:      candidate.PlatformID,
		PlatformModelID: candidate.PlatformModelID,
		ClientID:        candidate.ClientID,
		QueueKey:        candidate.QueueKey,
		Status:          "running",
		Simulated:       simulated,
		RequestSnapshot: body,
		Metrics:         attemptMetrics(candidate, attemptNo, simulated),
	})
	if err != nil {
		return clients.Response{}, err
	}
	reservations := s.rateLimitReservations(ctx, user, candidate, body)
	limitResult, err := s.store.ReserveRateLimits(ctx, task.ID, attemptID, reservations)
	if err != nil {
		clientErr := &clients.ClientError{Code: "rate_limit", Message: err.Error(), Retryable: false}
		_ = s.store.FinishTaskAttempt(ctx, store.FinishTaskAttemptInput{
			AttemptID:    attemptID,
			Status:       "failed",
			Retryable:    false,
			Metrics:      mergeMetrics(attemptMetrics(candidate, attemptNo, simulated), map[string]any{"error": err.Error(), "retryable": false, "trace": []any{failureTraceEntry(clientErr, false)}}),
			ErrorCode:    "rate_limit",
			ErrorMessage: err.Error(),
		})
		return clients.Response{}, clientErr
	}
	rateReservationsFinalized := false
	defer func() {
		if !rateReservationsFinalized {
			_ = s.store.ReleaseRateLimitReservations(context.WithoutCancel(ctx), limitResult.Reservations, "attempt_failed")
		}
	}()
	defer s.store.ReleaseConcurrencyLeases(context.WithoutCancel(ctx), limitResult.LeaseIDs)

	if err := s.store.RecordClientAssignment(ctx, candidate); err != nil {
		return clients.Response{}, err
	}
	defer s.store.RecordClientRelease(context.WithoutCancel(ctx), candidate.ClientID, "")

	requestHTTPClient, err := s.httpClientForCandidate(candidate, simulated)
	if err != nil {
		_ = s.store.FinishTaskAttempt(ctx, store.FinishTaskAttemptInput{
			AttemptID:    attemptID,
			Status:       "failed",
			Retryable:    false,
			Metrics:      mergeMetrics(attemptMetrics(candidate, attemptNo, simulated), map[string]any{"error": err.Error(), "retryable": false, "trace": []any{failureTraceEntry(err, false)}}),
			ErrorCode:    clients.ErrorCode(err),
			ErrorMessage: err.Error(),
		})
		return clients.Response{}, err
	}
	client := s.clientFor(candidate, simulated)
	callStartedAt := time.Now()
	response, err := client.Run(ctx, clients.Request{
		Kind:        task.Kind,
		ModelType:   candidate.ModelType,
		Model:       task.Model,
		Body:        body,
		Candidate:   candidate,
		HTTPClient:  requestHTTPClient,
		Stream:      boolFromMap(body, "stream"),
		StreamDelta: onDelta,
	})
	callFinishedAt := time.Now()
	if response.ResponseStartedAt.IsZero() {
		response.ResponseStartedAt = callStartedAt
	}
	if response.ResponseFinishedAt.IsZero() {
		response.ResponseFinishedAt = callFinishedAt
	}
	if response.ResponseDurationMS == 0 {
		response.ResponseDurationMS = response.ResponseFinishedAt.Sub(response.ResponseStartedAt).Milliseconds()
		if response.ResponseDurationMS < 0 {
			response.ResponseDurationMS = 0
		}
	}
	if err != nil {
		retryable := clients.IsRetryable(err)
		requestID, metrics, responseStartedAt, responseFinishedAt, responseDurationMS := failureMetrics(err, simulated)
		if responseStartedAt.IsZero() {
			responseStartedAt = callStartedAt
		}
		if responseFinishedAt.IsZero() {
			responseFinishedAt = callFinishedAt
		}
		if responseDurationMS == 0 {
			responseDurationMS = responseFinishedAt.Sub(responseStartedAt).Milliseconds()
			if responseDurationMS < 0 {
				responseDurationMS = 0
			}
		}
		metrics = mergeMetrics(attemptMetrics(candidate, attemptNo, simulated), metrics)
		_ = s.store.FinishTaskAttempt(ctx, store.FinishTaskAttemptInput{
			AttemptID:          attemptID,
			Status:             "failed",
			Retryable:          retryable,
			RequestID:          requestID,
			Metrics:            metrics,
			ResponseStartedAt:  responseStartedAt,
			ResponseFinishedAt: responseFinishedAt,
			ResponseDurationMS: responseDurationMS,
			ErrorCode:          clients.ErrorCode(err),
			ErrorMessage:       err.Error(),
		})
		_ = s.emit(ctx, task.ID, "task.attempt.failed", "running", "attempt_failed", 0.45, err.Error(), map[string]any{"attempt": attemptNo, "retryable": retryable, "requestId": requestID, "statusCode": clients.ErrorResponseMetadata(err).StatusCode, "metrics": metrics}, simulated)
		s.applyCandidateFailurePolicies(ctx, task.ID, candidate, err, simulated)
		return clients.Response{}, err
	}
	uploadedResult, err := s.uploadGeneratedAssets(ctx, response.Result)
	if err != nil {
		metrics := mergeMetrics(taskMetrics(task, user, body, candidate, response, simulated), map[string]any{
			"error":     err.Error(),
			"retryable": clients.IsRetryable(err),
			"trace":     []any{failureTraceEntry(err, clients.IsRetryable(err))},
		})
		_ = s.store.FinishTaskAttempt(ctx, store.FinishTaskAttemptInput{
			AttemptID:          attemptID,
			Status:             "failed",
			Retryable:          clients.IsRetryable(err),
			RequestID:          response.RequestID,
			Usage:              usageToMap(response.Usage),
			Metrics:            metrics,
			ResponseSnapshot:   response.Result,
			ResponseStartedAt:  response.ResponseStartedAt,
			ResponseFinishedAt: response.ResponseFinishedAt,
			ResponseDurationMS: response.ResponseDurationMS,
			ErrorCode:          clients.ErrorCode(err),
			ErrorMessage:       err.Error(),
		})
		return clients.Response{}, err
	}
	response.Result = uploadedResult
	for _, progress := range response.Progress {
		if err := s.emit(ctx, task.ID, "task.progress", "running", progress.Phase, progress.Progress, progress.Message, progress.Payload, simulated); err != nil {
			return clients.Response{}, err
		}
	}
	if err := s.store.CommitRateLimitReservations(ctx, limitResult.Reservations, tokenUsageAmounts(response.Usage)); err != nil {
		return clients.Response{}, err
	}
	rateReservationsFinalized = true
	if err := s.store.FinishTaskAttempt(ctx, store.FinishTaskAttemptInput{
		AttemptID:          attemptID,
		Status:             "succeeded",
		RequestID:          response.RequestID,
		Usage:              usageToMap(response.Usage),
		Metrics:            taskMetrics(task, user, body, candidate, response, simulated),
		ResponseSnapshot:   response.Result,
		ResponseStartedAt:  response.ResponseStartedAt,
		ResponseFinishedAt: response.ResponseFinishedAt,
		ResponseDurationMS: response.ResponseDurationMS,
	}); err != nil {
		return clients.Response{}, err
	}
	return response, nil
}

func (s *Service) clientFor(candidate store.RuntimeModelCandidate, simulated bool) clients.Client {
	if simulated {
		return s.clients["simulation"]
	}
	key := strings.ToLower(strings.TrimSpace(candidate.SpecType))
	if key == "" {
		key = strings.ToLower(strings.TrimSpace(candidate.Provider))
	}
	if client, ok := s.clients[key]; ok {
		return client
	}
	return s.clients["openai"]
}

func (s *Service) failTask(ctx context.Context, taskID string, code string, message string, simulated bool, cause error) (store.GatewayTask, error) {
	requestID, metrics, responseStartedAt, responseFinishedAt, responseDurationMS := failureMetrics(cause, simulated)
	metrics = s.withAttemptHistory(ctx, taskID, metrics)
	failed, err := s.store.FinishTaskFailure(ctx, store.FinishTaskFailureInput{
		TaskID:             taskID,
		Code:               code,
		Message:            message,
		RequestID:          requestID,
		Metrics:            metrics,
		ResponseStartedAt:  responseStartedAt,
		ResponseFinishedAt: responseFinishedAt,
		ResponseDurationMS: responseDurationMS,
	})
	if err != nil {
		return store.GatewayTask{}, err
	}
	if eventErr := s.emit(ctx, taskID, "task.failed", "failed", "failed", 1, message, map[string]any{"code": code, "requestId": requestID, "metrics": metrics}, simulated); eventErr != nil {
		return store.GatewayTask{}, eventErr
	}
	return failed, nil
}

func (s *Service) withAttemptHistory(ctx context.Context, taskID string, metrics map[string]any) map[string]any {
	attempts, err := s.store.ListTaskAttempts(ctx, taskID)
	if err != nil {
		s.logger.Warn("list task attempts for metrics failed", "taskID", taskID, "error", err)
		return metrics
	}
	if len(attempts) == 0 {
		return metrics
	}
	metrics = mergeMetrics(metrics)
	metrics["attemptCount"] = len(attempts)
	metrics["attempts"] = summarizeAttempts(attempts)
	return metrics
}

func (s *Service) emit(ctx context.Context, taskID string, eventType string, status string, phase string, progress float64, message string, payload map[string]any, simulated bool) error {
	event, err := s.store.AddTaskEvent(ctx, taskID, eventType, status, phase, progress, message, payload, simulated)
	if err != nil {
		return err
	}
	if s.cfg.TaskProgressCallbackEnabled {
		return s.store.QueueTaskCallback(ctx, event, s.cfg.TaskProgressCallbackURL)
	}
	return nil
}

func modelTypeFromKind(kind string, body map[string]any) string {
	switch kind {
	case "chat.completions", "responses":
		return "text_generate"
	case "images.generations", "images.edits":
		if kind == "images.edits" {
			return "image_edit"
		}
		return "image_generate"
	case "videos.generations":
		if videoRequestHasReferenceImage(body) {
			return "image_to_video"
		}
		return "video_generate"
	default:
		return "task"
	}
}

func videoRequestHasReferenceImage(body map[string]any) bool {
	if body == nil {
		return false
	}
	for _, key := range []string{
		"image", "images", "image_url", "imageUrl", "image_urls", "imageUrls",
		"reference_image", "referenceImage", "first_frame", "firstFrame", "last_frame", "lastFrame",
	} {
		if hasAnyString(body, key) {
			return true
		}
	}
	return false
}

func isTextGenerationKind(kind string) bool {
	return kind == "chat.completions" || kind == "responses"
}

func isSimulation(task store.GatewayTask, candidate store.RuntimeModelCandidate) bool {
	if task.RunMode == "simulation" {
		return true
	}
	return stringFromMap(candidate.Credentials, "mode") == "simulation" || boolFromMap(candidate.PlatformConfig, "testMode")
}

func retryEnabled(candidate store.RuntimeModelCandidate) bool {
	policy := effectiveRetryPolicy(candidate)
	if enabled, ok := policy["enabled"].(bool); ok {
		return enabled
	}
	return true
}

func clientAttemptsForCandidate(candidate store.RuntimeModelCandidate) int {
	if !retryEnabled(candidate) {
		return 1
	}
	if value := intFromPolicy(effectiveRetryPolicy(candidate), "maxAttempts"); value > 0 {
		return value
	}
	return 1
}

func maxPlatformsForCandidates(candidates []store.RuntimeModelCandidate, runnerPolicy store.RunnerPolicy) int {
	if len(candidates) == 0 {
		return 0
	}
	maxPlatforms := len(candidates)
	if value := intFromPolicy(runnerPolicy.FailoverPolicy, "maxPlatforms"); value > 0 {
		if value < maxPlatforms {
			maxPlatforms = value
		}
	} else if maxPlatforms > 99 {
		maxPlatforms = 99
	}
	for _, candidate := range candidates {
		if value := intFromPolicy(effectiveFailoverPolicy(runnerPolicy.FailoverPolicy, candidate.RuntimePolicyOverride), "maxPlatforms"); value > 0 && value < maxPlatforms {
			maxPlatforms = value
		}
	}
	if maxPlatforms <= 0 {
		return 1
	}
	return maxPlatforms
}

func maxFailoverDurationForCandidates(candidates []store.RuntimeModelCandidate, runnerPolicy store.RunnerPolicy) time.Duration {
	seconds := intFromPolicy(runnerPolicy.FailoverPolicy, "maxDurationSeconds")
	if seconds <= 0 {
		seconds = 600
	}
	for _, candidate := range candidates {
		if value := intFromPolicy(effectiveFailoverPolicy(runnerPolicy.FailoverPolicy, candidate.RuntimePolicyOverride), "maxDurationSeconds"); value > 0 && value < seconds {
			seconds = value
		}
	}
	return time.Duration(seconds) * time.Second
}

func failoverTimeBudgetExceeded(start time.Time, maxDuration time.Duration) bool {
	return maxDuration > 0 && time.Since(start) >= maxDuration
}

func normalizeRequest(kind string, body map[string]any) map[string]any {
	out := map[string]any{}
	for key, value := range body {
		out[key] = value
	}
	if kind == "responses" && out["messages"] == nil && out["input"] != nil {
		out["messages"] = []any{map[string]any{"role": "user", "content": out["input"]}}
	}
	return out
}

func validateRequest(kind string, body map[string]any) error {
	switch kind {
	case "chat.completions":
		if body["messages"] == nil {
			return errors.New("messages is required")
		}
	case "responses":
		if body["input"] == nil && body["messages"] == nil {
			return errors.New("input or messages is required")
		}
	case "images.generations", "images.edits":
		if strings.TrimSpace(stringFromMap(body, "prompt")) == "" {
			return errors.New("prompt is required")
		}
	}
	return nil
}