import { db } from '@sim/db'
import { workflow } from '@sim/db/schema'
import { createLogger } from '@sim/logger'
import {
  assertFolderMutable,
  assertWorkflowMutable,
  authorizeWorkflowByWorkspacePermission,
  FolderLockedError,
  WorkflowLockedError,
} from '@sim/platform-authz/workflow'
import { eq, sql } from 'drizzle-orm'
import { type NextRequest, NextResponse } from 'next/server'
import { updateWorkflowContract } from '@/lib/api/contracts/workflows'
import { parseRequest } from '@/lib/api/server'
import { AuthType, checkHybridAuth, checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
import { generateRequestId } from '@/lib/core/utils/request'
import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
import { captureServerEvent } from '@/lib/posthog/server'
import { performDeleteWorkflow, performUpdateWorkflow } from '@/lib/workflows/orchestration'
import { loadWorkflowFromNormalizedTables } from '@/lib/workflows/persistence/utils'
import { getWorkflowById } from '@/lib/workflows/utils'

const logger = createLogger('WorkflowByIdAPI')

/**
 * GET /api/workflows/[id]
 * Fetch a single workflow by ID
 * Uses hybrid approach: try normalized tables first, fallback to JSON blob
 */
export const GET = withRouteHandler(
  async (request: NextRequest, { params }: { params: Promise<{ id: string }> }) => {
    const requestId = generateRequestId()
    const startTime = Date.now()
    const { id: workflowId } = await params

    try {
      const auth = await checkHybridAuth(request, { requireWorkflowId: false })
      if (!auth.success) {
        logger.warn(`[${requestId}] Unauthorized access attempt for workflow ${workflowId}`)
        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
      }

      const isInternalCall = auth.authType === AuthType.INTERNAL_JWT
      const userId = auth.userId || null

      let workflowData = await getWorkflowById(workflowId)

      if (!workflowData) {
        logger.warn(`[${requestId}] Workflow ${workflowId} not found`)
        return NextResponse.json({ error: 'Workflow not found' }, { status: 404 })
      }

      if (auth.apiKeyType === 'workspace' && auth.workspaceId !== workflowData.workspaceId) {
        return NextResponse.json(
          { error: 'API key is not authorized for this workspace' },
          { status: 403 }
        )
      }

      if (isInternalCall && !userId) {
        // Internal system calls (e.g. workflow-in-workflow executor) may not carry a userId.
        // These are already authenticated via internal JWT; allow read access.
        logger.info(`[${requestId}] Internal API call for workflow ${workflowId}`)
      } else if (!userId) {
        logger.warn(`[${requestId}] Unauthorized access attempt for workflow ${workflowId}`)
        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
      } else {
        const authorization = await authorizeWorkflowByWorkspacePermission({
          workflowId,
          userId,
          action: 'read',
        })
        if (!authorization.workflow) {
          logger.warn(`[${requestId}] Workflow ${workflowId} not found`)
          return NextResponse.json({ error: 'Workflow not found' }, { status: 404 })
        }

        workflowData = authorization.workflow
        if (!authorization.allowed) {
          logger.warn(`[${requestId}] User ${userId} denied access to workflow ${workflowId}`)
          return NextResponse.json(
            { error: authorization.message || 'Access denied' },
            { status: authorization.status }
          )
        }
      }

      const snapshot = await db.transaction(async (tx) => {
        await tx.execute(sql`SET TRANSACTION ISOLATION LEVEL REPEATABLE READ`)
        const [normalizedData, [workflowRecord]] = await Promise.all([
          loadWorkflowFromNormalizedTables(workflowId, tx),
          tx.select().from(workflow).where(eq(workflow.id, workflowId)).limit(1),
        ])
        return { normalizedData, workflowRecord }
      })
      const responseWorkflowData = snapshot.workflowRecord ?? workflowData

      // Stamp `workflowId` from the path param on each variable so the
      // global client-side variables store can filter by workflow without
      // requiring persisted variables to carry a redundant `workflowId`.
      // The persisted blob may or may not include `workflowId` depending on
      // when the variable was last written; the path param is authoritative.
      const persistedVariables =
        (responseWorkflowData.variables as Record<string, Record<string, unknown>>) || {}
      const stampedVariables: Record<string, Record<string, unknown>> = {}
      for (const [variableId, variable] of Object.entries(persistedVariables)) {
        if (variable && typeof variable === 'object') {
          stampedVariables[variableId] = { ...variable, workflowId }
        }
      }
      const workflowStateMetadata = {
        name: responseWorkflowData.name,
        ...(typeof responseWorkflowData.description === 'string'
          ? { description: responseWorkflowData.description }
          : {}),
      }

      if (snapshot.normalizedData) {
        const finalWorkflowData = {
          ...responseWorkflowData,
          state: {
            blocks: snapshot.normalizedData.blocks,
            edges: snapshot.normalizedData.edges,
            loops: snapshot.normalizedData.loops,
            parallels: snapshot.normalizedData.parallels,
            lastSaved: Date.now(),
            isDeployed: responseWorkflowData.isDeployed || false,
            deployedAt: responseWorkflowData.deployedAt,
            metadata: workflowStateMetadata,
          },
          variables: stampedVariables,
        }

        logger.info(`[${requestId}] Loaded workflow ${workflowId} from normalized tables`)
        const elapsed = Date.now() - startTime
        logger.info(`[${requestId}] Successfully fetched workflow ${workflowId} in ${elapsed}ms`)

        return NextResponse.json({ data: finalWorkflowData }, { status: 200 })
      }

      const emptyWorkflowData = {
        ...responseWorkflowData,
        state: {
          blocks: {},
          edges: [],
          loops: {},
          parallels: {},
          lastSaved: Date.now(),
          isDeployed: responseWorkflowData.isDeployed || false,
          deployedAt: responseWorkflowData.deployedAt,
          metadata: workflowStateMetadata,
        },
        variables: stampedVariables,
      }

      return NextResponse.json({ data: emptyWorkflowData }, { status: 200 })
    } catch (error: any) {
      const elapsed = Date.now() - startTime
      logger.error(`[${requestId}] Error fetching workflow ${workflowId} after ${elapsed}ms`, error)
      return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
    }
  }
)

/**
 * DELETE /api/workflows/[id]
 * Delete a workflow by ID
 */
export const DELETE = withRouteHandler(
  async (request: NextRequest, { params }: { params: Promise<{ id: string }> }) => {
    const requestId = generateRequestId()
    const startTime = Date.now()
    const { id: workflowId } = await params

    try {
      const auth = await checkSessionOrInternalAuth(request, { requireWorkflowId: false })
      if (!auth.success || !auth.userId) {
        logger.warn(`[${requestId}] Unauthorized deletion attempt for workflow ${workflowId}`)
        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
      }

      const userId = auth.userId

      const authorization = await authorizeWorkflowByWorkspacePermission({
        workflowId,
        userId,
        action: 'write',
      })
      const workflowData = authorization.workflow || (await getWorkflowById(workflowId))

      if (!workflowData) {
        logger.warn(`[${requestId}] Workflow ${workflowId} not found for deletion`)
        return NextResponse.json({ error: 'Workflow not found' }, { status: 404 })
      }

      const canDelete = authorization.allowed

      if (!canDelete) {
        logger.warn(
          `[${requestId}] User ${userId} denied permission to delete workflow ${workflowId}`
        )
        return NextResponse.json(
          { error: authorization.message || 'Access denied' },
          { status: authorization.status || 403 }
        )
      }

      await assertWorkflowMutable(workflowId)

      const result = await performDeleteWorkflow({
        workflowId,
        userId,
        requestId,
      })

      if (!result.success) {
        const status =
          result.errorCode === 'not_found' ? 404 : result.errorCode === 'validation' ? 400 : 500
        return NextResponse.json({ error: result.error }, { status })
      }

      captureServerEvent(
        userId,
        'workflow_deleted',
        { workflow_id: workflowId, workspace_id: workflowData.workspaceId ?? '' },
        workflowData.workspaceId ? { groups: { workspace: workflowData.workspaceId } } : undefined
      )

      const elapsed = Date.now() - startTime
      logger.info(`[${requestId}] Successfully archived workflow ${workflowId} in ${elapsed}ms`)

      return NextResponse.json({ success: true }, { status: 200 })
    } catch (error: any) {
      if (error instanceof WorkflowLockedError) {
        return NextResponse.json({ error: error.message }, { status: error.status })
      }

      const elapsed = Date.now() - startTime
      logger.error(`[${requestId}] Error deleting workflow ${workflowId} after ${elapsed}ms`, error)
      return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
    }
  }
)

/**
 * PUT /api/workflows/[id]
 * Update workflow metadata (name, description, folderId)
 */
export const PUT = withRouteHandler(
  async (request: NextRequest, context: { params: Promise<{ id: string }> }) => {
    const requestId = generateRequestId()
    const startTime = Date.now()
    const { id: workflowId } = await context.params

    try {
      const auth = await checkSessionOrInternalAuth(request, { requireWorkflowId: false })
      if (!auth.success || !auth.userId) {
        logger.warn(`[${requestId}] Unauthorized update attempt for workflow ${workflowId}`)
        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
      }

      const userId = auth.userId

      const parsed = await parseRequest(updateWorkflowContract, request, context)
      if (!parsed.success) return parsed.response
      const updates = parsed.data.body

      // Fetch the workflow to check ownership/access
      const authorization = await authorizeWorkflowByWorkspacePermission({
        workflowId,
        userId,
        action: 'write',
      })
      const workflowData = authorization.workflow || (await getWorkflowById(workflowId))

      if (!workflowData) {
        logger.warn(`[${requestId}] Workflow ${workflowId} not found for update`)
        return NextResponse.json({ error: 'Workflow not found' }, { status: 404 })
      }

      const canUpdate = authorization.allowed

      if (!canUpdate) {
        logger.warn(
          `[${requestId}] User ${userId} denied permission to update workflow ${workflowId}`
        )
        return NextResponse.json(
          { error: authorization.message || 'Access denied' },
          { status: authorization.status || 403 }
        )
      }

      if (updates.locked !== undefined && authorization.workspacePermission !== 'admin') {
        logger.warn(
          `[${requestId}] User ${userId} denied permission to lock workflow ${workflowId}`
        )
        return NextResponse.json(
          { error: 'Admin access required to lock workflows' },
          { status: 403 }
        )
      }

      const hasNonLockUpdate = Object.keys(updates).some((key) => key !== 'locked')
      if (hasNonLockUpdate) {
        await assertWorkflowMutable(workflowId)
      }
      if (updates.folderId !== undefined) {
        await assertFolderMutable(updates.folderId)
      }

      if (!workflowData.workspaceId) {
        logger.error(`[${requestId}] Workflow ${workflowId} has no workspaceId`)
        return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
      }

      const result = await performUpdateWorkflow({
        workflowId,
        userId,
        workspaceId: workflowData.workspaceId,
        currentName: workflowData.name,
        currentFolderId: workflowData.folderId,
        currentLocked: workflowData.locked,
        ...updates,
        requestId,
      })

      if (!result.success || !result.workflow) {
        const status =
          result.errorCode === 'not_found'
            ? 404
            : result.errorCode === 'conflict'
              ? 409
              : result.errorCode === 'validation'
                ? 400
                : 500
        return NextResponse.json({ error: result.error }, { status })
      }

      const elapsed = Date.now() - startTime
      logger.info(`[${requestId}] Successfully updated workflow ${workflowId} in ${elapsed}ms`, {
        updates,
      })

      return NextResponse.json({ workflow: result.workflow }, { status: 200 })
    } catch (error: any) {
      if (error instanceof WorkflowLockedError || error instanceof FolderLockedError) {
        return NextResponse.json({ error: error.message }, { status: error.status })
      }

      const elapsed = Date.now() - startTime
      logger.error(`[${requestId}] Error updating workflow ${workflowId} after ${elapsed}ms`, error)
      return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
    }
  }
)