import { AuditAction, AuditResourceType, recordAudit } from '@sim/audit'
import { db } from '@sim/db'
import { knowledgeBase, knowledgeBaseTagDefinitions, knowledgeConnector } from '@sim/db/schema'
import { createLogger } from '@sim/logger'
import { generateId } from '@sim/utils/id'
import { and, desc, eq, isNull, sql } from 'drizzle-orm'
import { type NextRequest, NextResponse } from 'next/server'
import { createKnowledgeConnectorContract } from '@/lib/api/contracts/knowledge'
import { parseRequest } from '@/lib/api/server'
import { encryptApiKey } from '@/lib/api-key/crypto'
import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
import { hasLiveSyncAccess } from '@/lib/billing/core/subscription'
import { generateRequestId } from '@/lib/core/utils/request'
import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
import { dispatchSync } from '@/lib/knowledge/connectors/sync-engine'
import { allocateTagSlots } from '@/lib/knowledge/constants'
import { createTagDefinition } from '@/lib/knowledge/tags/service'
import { captureServerEvent } from '@/lib/posthog/server'
import { getCredential } from '@/app/api/auth/oauth/utils'
import { checkKnowledgeBaseAccess, checkKnowledgeBaseWriteAccess } from '@/app/api/knowledge/utils'
import { CONNECTOR_REGISTRY } from '@/connectors/registry.server'

const logger = createLogger('KnowledgeConnectorsAPI')

/**
 * GET /api/knowledge/[id]/connectors - List connectors for a knowledge base
 */
export const GET = withRouteHandler(
  async (request: NextRequest, { params }: { params: Promise<{ id: string }> }) => {
    const requestId = generateRequestId()
    const { id: knowledgeBaseId } = await params

    try {
      const auth = await checkSessionOrInternalAuth(request, { requireWorkflowId: false })
      if (!auth.success || !auth.userId) {
        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
      }

      const accessCheck = await checkKnowledgeBaseAccess(knowledgeBaseId, auth.userId)
      if (!accessCheck.hasAccess) {
        const status = 'notFound' in accessCheck && accessCheck.notFound ? 404 : 401
        return NextResponse.json(
          { error: status === 404 ? 'Not found' : 'Unauthorized' },
          { status }
        )
      }

      const connectors = await db
        .select()
        .from(knowledgeConnector)
        .where(
          and(
            eq(knowledgeConnector.knowledgeBaseId, knowledgeBaseId),
            isNull(knowledgeConnector.archivedAt),
            isNull(knowledgeConnector.deletedAt)
          )
        )
        .orderBy(desc(knowledgeConnector.createdAt))

      return NextResponse.json({
        success: true,
        data: connectors.map(({ encryptedApiKey: _, ...rest }) => rest),
      })
    } catch (error) {
      logger.error(`[${requestId}] Error listing connectors`, error)
      return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
    }
  }
)

/**
 * POST /api/knowledge/[id]/connectors - Create a new connector
 */
export const POST = withRouteHandler(
  async (request: NextRequest, context: { params: Promise<{ id: string }> }) => {
    const requestId = generateRequestId()
    const { id: knowledgeBaseId } = await context.params

    try {
      const auth = await checkSessionOrInternalAuth(request, { requireWorkflowId: false })
      if (!auth.success || !auth.userId) {
        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
      }

      const writeCheck = await checkKnowledgeBaseWriteAccess(knowledgeBaseId, auth.userId)
      if (!writeCheck.hasAccess) {
        const status = 'notFound' in writeCheck && writeCheck.notFound ? 404 : 401
        return NextResponse.json(
          { error: status === 404 ? 'Not found' : 'Unauthorized' },
          { status }
        )
      }

      const parsed = await parseRequest(createKnowledgeConnectorContract, request, context)
      if (!parsed.success) return parsed.response

      const { connectorType, credentialId, apiKey, sourceConfig, syncIntervalMinutes } =
        parsed.data.body

      if (syncIntervalMinutes > 0 && syncIntervalMinutes < 60) {
        const canUseLiveSync = await hasLiveSyncAccess(auth.userId)
        if (!canUseLiveSync) {
          return NextResponse.json(
            { error: 'Live sync requires a Max or Enterprise plan' },
            { status: 403 }
          )
        }
      }

      const connectorConfig = CONNECTOR_REGISTRY[connectorType]
      if (!connectorConfig) {
        return NextResponse.json(
          { error: `Unknown connector type: ${connectorType}` },
          { status: 400 }
        )
      }

      let resolvedCredentialId: string | null = null
      let resolvedEncryptedApiKey: string | null = null
      let accessToken: string

      if (connectorConfig.auth.mode === 'apiKey') {
        if (!apiKey) {
          return NextResponse.json({ error: 'API key is required' }, { status: 400 })
        }
        accessToken = apiKey
      } else {
        if (!credentialId) {
          return NextResponse.json({ error: 'Credential is required' }, { status: 400 })
        }

        const credential = await getCredential(requestId, credentialId, auth.userId)
        if (!credential) {
          return NextResponse.json({ error: 'Credential not found' }, { status: 400 })
        }

        if (!credential.accessToken) {
          return NextResponse.json(
            { error: 'Credential has no access token. Please reconnect your account.' },
            { status: 400 }
          )
        }

        accessToken = credential.accessToken
        resolvedCredentialId = credentialId
      }

      const configValidation = await connectorConfig.validateConfig(accessToken, sourceConfig)
      if (!configValidation.valid) {
        return NextResponse.json(
          { error: configValidation.error || 'Invalid source configuration' },
          { status: 400 }
        )
      }

      let finalSourceConfig: Record<string, unknown> = { ...sourceConfig }

      if (connectorConfig.auth.mode === 'apiKey' && apiKey) {
        const { encrypted } = await encryptApiKey(apiKey)
        resolvedEncryptedApiKey = encrypted
      }

      const tagSlotMapping: Record<string, string> = {}
      let newTagSlots: Record<string, string> = {}

      if (connectorConfig.tagDefinitions?.length) {
        const disabledIds = new Set((sourceConfig.disabledTagIds as string[] | undefined) ?? [])
        const enabledDefs = connectorConfig.tagDefinitions.filter((td) => !disabledIds.has(td.id))

        const existingDefs = await db
          .select({
            tagSlot: knowledgeBaseTagDefinitions.tagSlot,
            displayName: knowledgeBaseTagDefinitions.displayName,
            fieldType: knowledgeBaseTagDefinitions.fieldType,
          })
          .from(knowledgeBaseTagDefinitions)
          .where(eq(knowledgeBaseTagDefinitions.knowledgeBaseId, knowledgeBaseId))

        const usedSlots = new Set<string>(existingDefs.map((d) => d.tagSlot))
        const existingByName = new Map(
          existingDefs.map((d) => [d.displayName, { tagSlot: d.tagSlot, fieldType: d.fieldType }])
        )

        const defsNeedingSlots: typeof enabledDefs = []
        for (const td of enabledDefs) {
          const existing = existingByName.get(td.displayName)
          if (existing && existing.fieldType === td.fieldType) {
            tagSlotMapping[td.id] = existing.tagSlot
          } else {
            defsNeedingSlots.push(td)
          }
        }

        const { mapping, skipped: skippedTags } = allocateTagSlots(defsNeedingSlots, usedSlots)
        Object.assign(tagSlotMapping, mapping)
        newTagSlots = mapping

        for (const name of skippedTags) {
          logger.warn(`[${requestId}] No available slots for "${name}"`)
        }

        if (skippedTags.length > 0 && Object.keys(tagSlotMapping).length === 0) {
          return NextResponse.json(
            { error: `No available tag slots. Could not assign: ${skippedTags.join(', ')}` },
            { status: 422 }
          )
        }

        finalSourceConfig = { ...finalSourceConfig, tagSlotMapping }
      }

      const now = new Date()
      const connectorId = generateId()
      const nextSyncAt =
        syncIntervalMinutes > 0 ? new Date(now.getTime() + syncIntervalMinutes * 60 * 1000) : null

      await db.transaction(async (tx) => {
        await tx.execute(sql`SELECT 1 FROM knowledge_base WHERE id = ${knowledgeBaseId} FOR UPDATE`)

        const activeKb = await tx
          .select({ id: knowledgeBase.id })
          .from(knowledgeBase)
          .where(and(eq(knowledgeBase.id, knowledgeBaseId), isNull(knowledgeBase.deletedAt)))
          .limit(1)

        if (activeKb.length === 0) {
          throw new Error('Knowledge base not found')
        }

        for (const [semanticId, slot] of Object.entries(newTagSlots)) {
          const td = connectorConfig.tagDefinitions!.find((d) => d.id === semanticId)!
          await createTagDefinition(
            {
              knowledgeBaseId,
              tagSlot: slot,
              displayName: td.displayName,
              fieldType: td.fieldType,
            },
            requestId,
            tx
          )
        }

        await tx.insert(knowledgeConnector).values({
          id: connectorId,
          knowledgeBaseId,
          connectorType,
          credentialId: resolvedCredentialId,
          encryptedApiKey: resolvedEncryptedApiKey,
          sourceConfig: finalSourceConfig,
          syncIntervalMinutes,
          status: 'active',
          nextSyncAt,
          createdAt: now,
          updatedAt: now,
        })
      })

      logger.info(`[${requestId}] Created connector ${connectorId} for KB ${knowledgeBaseId}`)

      const kbWorkspaceId = writeCheck.knowledgeBase.workspaceId ?? ''
      captureServerEvent(
        auth.userId,
        'knowledge_base_connector_added',
        {
          knowledge_base_id: knowledgeBaseId,
          workspace_id: kbWorkspaceId,
          connector_type: connectorType,
          sync_interval_minutes: syncIntervalMinutes,
        },
        {
          groups: kbWorkspaceId ? { workspace: kbWorkspaceId } : undefined,
          setOnce: { first_connector_added_at: new Date().toISOString() },
        }
      )

      recordAudit({
        workspaceId: writeCheck.knowledgeBase.workspaceId,
        actorId: auth.userId,
        actorName: auth.userName,
        actorEmail: auth.userEmail,
        action: AuditAction.CONNECTOR_CREATED,
        resourceType: AuditResourceType.CONNECTOR,
        resourceId: connectorId,
        resourceName: connectorType,
        description: `Created ${connectorType} connector for knowledge base "${writeCheck.knowledgeBase.name}"`,
        metadata: {
          knowledgeBaseId,
          knowledgeBaseName: writeCheck.knowledgeBase.name,
          connectorType,
          syncIntervalMinutes,
          authMode: connectorConfig.auth.mode,
        },
        request,
      })

      dispatchSync(connectorId, { requestId }).catch((error) => {
        logger.error(
          `[${requestId}] Failed to dispatch initial sync for connector ${connectorId}`,
          error
        )
      })

      const created = await db
        .select()
        .from(knowledgeConnector)
        .where(eq(knowledgeConnector.id, connectorId))
        .limit(1)

      const { encryptedApiKey: _, ...createdData } = created[0]
      return NextResponse.json({ success: true, data: createdData }, { status: 201 })
    } catch (error) {
      if (error instanceof Error && error.message === 'Knowledge base not found') {
        return NextResponse.json({ error: 'Not found' }, { status: 404 })
      }
      logger.error(`[${requestId}] Error creating connector`, error)
      return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
    }
  }
)