package store

import (
	"context"
	"encoding/json"
	"errors"

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

const identityRevisionColumns = `
id::text,state,schema_version,auth_center_url,COALESCE(issuer,''),COALESCE(tenant_id,''),COALESCE(application_id,''),
COALESCE(audience,''),COALESCE(browser_client_id,''),COALESCE(machine_client_id,''),scopes,capabilities,role_prefix,
local_tenant_key,public_base_url,web_base_url,jit_enabled,legacy_jwt_enabled,token_introspection,session_revocation,
COALESCE(security_event_issuer,''),COALESCE(security_event_configuration_url,''),COALESCE(security_event_audience,''),
COALESCE(machine_credential_ref,''),COALESCE(session_encryption_key_ref,''),session_idle_seconds,session_absolute_seconds,
session_refresh_seconds,version,COALESCE(last_error_category,''),COALESCE(last_trace_id,''),COALESCE(last_audit_id,''),
validated_at,activated_at,superseded_at,created_at,updated_at`

func (s *Store) CreateIdentityConfigurationRevision(ctx context.Context, revision identity.Revision) (identity.Revision, error) {
	scopes, _ := json.Marshal(revision.Scopes)
	capabilities, _ := json.Marshal(revision.Capabilities)
	return scanIdentityRevision(s.pool.QueryRow(ctx, `
INSERT INTO gateway_identity_configuration_revisions (
  id,state,schema_version,auth_center_url,role_prefix,local_tenant_key,public_base_url,web_base_url,
  jit_enabled,legacy_jwt_enabled,scopes,capabilities,session_idle_seconds,session_absolute_seconds,session_refresh_seconds
) VALUES ($1::uuid,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11::jsonb,$12::jsonb,$13,$14,$15)
RETURNING `+identityRevisionColumns,
		revision.ID, revision.State, revision.SchemaVersion, revision.AuthCenterURL, revision.RolePrefix,
		revision.LocalTenantKey, revision.PublicBaseURL, revision.WebBaseURL, revision.JITEnabled, revision.LegacyJWTEnabled,
		string(scopes), string(capabilities), revision.SessionIdleSeconds, revision.SessionAbsoluteSeconds, revision.SessionRefreshSeconds,
	))
}

func (s *Store) IdentityConfigurationRevision(ctx context.Context, id string) (identity.Revision, error) {
	revision, err := scanIdentityRevision(s.pool.QueryRow(ctx, `SELECT `+identityRevisionColumns+`
FROM gateway_identity_configuration_revisions WHERE id=$1::uuid`, id))
	return revision, normalizeIdentityRevisionError(err)
}

func (s *Store) ActiveIdentityConfigurationRevision(ctx context.Context) (identity.Revision, error) {
	revision, err := scanIdentityRevision(s.pool.QueryRow(ctx, `SELECT `+identityRevisionColumns+`
FROM gateway_identity_configuration_revisions WHERE state='active'`))
	return revision, normalizeIdentityRevisionError(err)
}

func (s *Store) ApplyIdentityManifest(ctx context.Context, id string, expectedVersion int64, applied identity.ManifestApplication) (identity.Revision, error) {
	current, err := s.IdentityConfigurationRevision(ctx, id)
	if err != nil {
		return identity.Revision{}, err
	}
	if current.Version != expectedVersion {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	updated, err := identity.ApplyManifest(current, applied)
	if err != nil {
		return identity.Revision{}, err
	}
	scopes, _ := json.Marshal(updated.Scopes)
	capabilities, _ := json.Marshal(updated.Capabilities)
	revision, err := scanIdentityRevision(s.pool.QueryRow(ctx, `
UPDATE gateway_identity_configuration_revisions SET
  issuer=$3,tenant_id=$4,application_id=$5,audience=NULLIF($6,''),browser_client_id=NULLIF($7,''),machine_client_id=NULLIF($8,''),
  scopes=$9::jsonb,capabilities=$10::jsonb,token_introspection=$11,session_revocation=$12,
  security_event_issuer=NULLIF($13,''),security_event_configuration_url=NULLIF($14,''),security_event_audience=NULLIF($15,''),
  machine_credential_ref=NULLIF($16,''),session_encryption_key_ref=NULLIF($17,''),last_trace_id=NULLIF($18,''),
  last_audit_id=NULLIF($19,''),last_error_category=NULL,version=version+1,updated_at=now()
WHERE id=$1::uuid AND version=$2 AND state='draft'
RETURNING `+identityRevisionColumns,
		id, expectedVersion, updated.Issuer, updated.TenantID, updated.ApplicationID, updated.Audience,
		updated.BrowserClientID, updated.MachineClientID, string(scopes), string(capabilities), updated.TokenIntrospection,
		updated.SessionRevocation, updated.SecurityEventIssuer, updated.SecurityEventConfigURL, updated.SecurityEventAudience,
		updated.MachineCredentialRef, updated.SessionEncryptionKeyRef, updated.LastTraceID, updated.LastAuditID,
	))
	if errors.Is(err, pgx.ErrNoRows) {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	return revision, err
}

func (s *Store) MarkIdentityRevisionValidated(ctx context.Context, id string, expectedVersion int64, traceID, auditID string) (identity.Revision, error) {
	revision, err := scanIdentityRevision(s.pool.QueryRow(ctx, `
UPDATE gateway_identity_configuration_revisions SET state='validated',validated_at=now(),last_error_category=NULL,
  last_trace_id=NULLIF($3,''),last_audit_id=NULLIF($4,''),version=version+1,updated_at=now()
WHERE id=$1::uuid AND version=$2 AND state IN ('draft','superseded')
RETURNING `+identityRevisionColumns, id, expectedVersion, traceID, auditID))
	if errors.Is(err, pgx.ErrNoRows) {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	return revision, err
}

func (s *Store) MarkIdentityRevisionFailed(ctx context.Context, id string, expectedVersion int64, category, traceID, auditID string) (identity.Revision, error) {
	revision, err := scanIdentityRevision(s.pool.QueryRow(ctx, `
UPDATE gateway_identity_configuration_revisions SET state='failed',last_error_category=NULLIF($3,''),
  last_trace_id=NULLIF($4,''),last_audit_id=NULLIF($5,''),version=version+1,updated_at=now()
WHERE id=$1::uuid AND version=$2 AND state IN ('draft','validated')
RETURNING `+identityRevisionColumns, id, expectedVersion, category, traceID, auditID))
	if errors.Is(err, pgx.ErrNoRows) {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	return revision, err
}

func (s *Store) ActivateIdentityRevision(ctx context.Context, id string, expectedVersion int64) (identity.Revision, bool, error) {
	tx, err := s.pool.BeginTx(ctx, pgx.TxOptions{IsoLevel: pgx.Serializable})
	if err != nil {
		return identity.Revision{}, false, err
	}
	defer tx.Rollback(ctx)
	if ok, err := hasBreakGlassManager(ctx, tx); err != nil {
		return identity.Revision{}, false, err
	} else if !ok {
		return identity.Revision{}, false, identity.ErrBreakGlassRequired
	}
	var tenantExists bool
	if err := tx.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM gateway_tenants WHERE tenant_key=(
SELECT local_tenant_key FROM gateway_identity_configuration_revisions WHERE id=$1::uuid) AND status='active')`, id).Scan(&tenantExists); err != nil {
		return identity.Revision{}, false, err
	}
	if !tenantExists {
		return identity.Revision{}, false, identity.ErrLocalTenantInvalid
	}
	var previousID, previousIssuer, previousTenant, previousAudience, previousClient, previousSessionRef string
	_ = tx.QueryRow(ctx, `SELECT id::text,COALESCE(issuer,''),COALESCE(tenant_id,''),COALESCE(audience,''),
COALESCE(browser_client_id,''),COALESCE(session_encryption_key_ref,'') FROM gateway_identity_configuration_revisions
WHERE state='active' FOR UPDATE`).Scan(&previousID, &previousIssuer, &previousTenant, &previousAudience, &previousClient, &previousSessionRef)
	var nextIssuer, nextTenant, nextAudience, nextClient, nextSessionRef string
	if err := tx.QueryRow(ctx, `SELECT COALESCE(issuer,''),COALESCE(tenant_id,''),COALESCE(audience,''),
COALESCE(browser_client_id,''),COALESCE(session_encryption_key_ref,'') FROM gateway_identity_configuration_revisions
WHERE id=$1::uuid AND version=$2 AND state='validated' FOR UPDATE`, id, expectedVersion).Scan(
		&nextIssuer, &nextTenant, &nextAudience, &nextClient, &nextSessionRef,
	); errors.Is(err, pgx.ErrNoRows) {
		return identity.Revision{}, false, identity.ErrRevisionConflict
	} else if err != nil {
		return identity.Revision{}, false, err
	}
	if previousID != "" {
		if _, err := tx.Exec(ctx, `UPDATE gateway_identity_configuration_revisions SET state='superseded',superseded_at=now(),
version=version+1,updated_at=now() WHERE id=$1::uuid AND state='active'`, previousID); err != nil {
			return identity.Revision{}, false, err
		}
	}
	revision, err := scanIdentityRevision(tx.QueryRow(ctx, `UPDATE gateway_identity_configuration_revisions SET state='active',
activated_at=now(),superseded_at=NULL,version=version+1,updated_at=now() WHERE id=$1::uuid AND version=$2 AND state='validated'
RETURNING `+identityRevisionColumns, id, expectedVersion))
	if err != nil {
		return identity.Revision{}, false, err
	}
	identityChanged := previousID != "" && (previousIssuer != nextIssuer || previousTenant != nextTenant || previousAudience != nextAudience || previousClient != nextClient || previousSessionRef != nextSessionRef)
	if identityChanged {
		if _, err := tx.Exec(ctx, `DELETE FROM gateway_oidc_sessions`); err != nil {
			return identity.Revision{}, false, err
		}
	}
	if err := tx.Commit(ctx); err != nil {
		return identity.Revision{}, false, err
	}
	return revision, identityChanged, nil
}

func (s *Store) DisableActiveIdentityRevision(ctx context.Context, expectedVersion int64) (identity.Revision, error) {
	tx, err := s.pool.BeginTx(ctx, pgx.TxOptions{IsoLevel: pgx.Serializable})
	if err != nil {
		return identity.Revision{}, err
	}
	defer tx.Rollback(ctx)
	if ok, err := hasBreakGlassManager(ctx, tx); err != nil {
		return identity.Revision{}, err
	} else if !ok {
		return identity.Revision{}, identity.ErrBreakGlassRequired
	}
	revision, err := scanIdentityRevision(tx.QueryRow(ctx, `UPDATE gateway_identity_configuration_revisions SET state='superseded',
superseded_at=now(),version=version+1,updated_at=now() WHERE state='active' AND version=$1 RETURNING `+identityRevisionColumns, expectedVersion))
	if errors.Is(err, pgx.ErrNoRows) {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	if err != nil {
		return identity.Revision{}, err
	}
	if _, err := tx.Exec(ctx, `DELETE FROM gateway_oidc_sessions`); err != nil {
		return identity.Revision{}, err
	}
	if err := tx.Commit(ctx); err != nil {
		return identity.Revision{}, err
	}
	return revision, nil
}

func (s *Store) HasBreakGlassManager(ctx context.Context) (bool, error) {
	return hasBreakGlassManager(ctx, s.pool)
}

func (s *Store) HasActiveTenantKey(ctx context.Context, tenantKey string) (bool, error) {
	var exists bool
	err := s.pool.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM gateway_tenants WHERE tenant_key=$1 AND status='active')`, tenantKey).Scan(&exists)
	return exists, err
}

func hasBreakGlassManager(ctx context.Context, query interface {
	QueryRow(context.Context, string, ...any) pgx.Row
}) (bool, error) {
	var exists bool
	err := query.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM gateway_users WHERE source='gateway' AND status='active'
AND deleted_at IS NULL AND password_hash IS NOT NULL AND password_hash <> '' AND (roles ? 'manager' OR roles ? 'admin'))`).Scan(&exists)
	return exists, err
}

func scanIdentityRevision(row scanner) (identity.Revision, error) {
	var revision identity.Revision
	var state string
	var scopes, capabilities []byte
	if err := row.Scan(
		&revision.ID, &state, &revision.SchemaVersion, &revision.AuthCenterURL, &revision.Issuer, &revision.TenantID,
		&revision.ApplicationID, &revision.Audience, &revision.BrowserClientID, &revision.MachineClientID, &scopes,
		&capabilities, &revision.RolePrefix, &revision.LocalTenantKey, &revision.PublicBaseURL, &revision.WebBaseURL,
		&revision.JITEnabled, &revision.LegacyJWTEnabled, &revision.TokenIntrospection, &revision.SessionRevocation,
		&revision.SecurityEventIssuer, &revision.SecurityEventConfigURL, &revision.SecurityEventAudience,
		&revision.MachineCredentialRef, &revision.SessionEncryptionKeyRef, &revision.SessionIdleSeconds,
		&revision.SessionAbsoluteSeconds, &revision.SessionRefreshSeconds, &revision.Version, &revision.LastErrorCategory,
		&revision.LastTraceID, &revision.LastAuditID, &revision.ValidatedAt, &revision.ActivatedAt, &revision.SupersededAt,
		&revision.CreatedAt, &revision.UpdatedAt,
	); err != nil {
		return identity.Revision{}, err
	}
	revision.State = identity.RevisionState(state)
	_ = json.Unmarshal(scopes, &revision.Scopes)
	_ = json.Unmarshal(capabilities, &revision.Capabilities)
	if revision.Scopes == nil {
		revision.Scopes = []string{}
	}
	if revision.Capabilities == nil {
		revision.Capabilities = []string{}
	}
	return revision, nil
}

func normalizeIdentityRevisionError(err error) error {
	if errors.Is(err, pgx.ErrNoRows) {
		return identity.ErrRevisionNotFound
	}
	return err
}