import { z } from 'zod'
import { TRPCError } from '@trpc/server'
import { Prisma } from '@prisma/client'
import { router, protectedProcedure, adminProcedure, awardMasterProcedure } from '../trpc'
import { logAudit } from '@/server/utils/audit'

export const awardRouter = router({
  /**
   * Create a new award track within a pipeline
   */
  createTrack: adminProcedure
    .input(
      z.object({
        pipelineId: z.string(),
        name: z.string().min(1).max(255),
        slug: z.string().min(1).max(100).regex(/^[a-z0-9-]+$/),
        routingMode: z.enum(['PARALLEL', 'EXCLUSIVE', 'POST_MAIN']).optional(),
        decisionMode: z.enum(['JURY_VOTE', 'AWARD_MASTER_DECISION', 'ADMIN_DECISION']).optional(),
        settingsJson: z.record(z.unknown()).optional(),
        awardConfig: z.object({
          name: z.string().min(1).max(255),
          description: z.string().max(5000).optional(),
          criteriaText: z.string().max(5000).optional(),
          scoringMode: z.enum(['PICK_WINNER', 'RANKED', 'SCORED']).default('PICK_WINNER'),
          maxRankedPicks: z.number().int().min(1).max(20).optional(),
          useAiEligibility: z.boolean().default(true),
        }),
      })
    )
    .mutation(async ({ ctx, input }) => {
      // Verify pipeline exists
      const pipeline = await ctx.prisma.pipeline.findUniqueOrThrow({
        where: { id: input.pipelineId },
      })

      // Check slug uniqueness within pipeline
      const existingTrack = await ctx.prisma.track.findFirst({
        where: {
          pipelineId: input.pipelineId,
          slug: input.slug,
        },
      })
      if (existingTrack) {
        throw new TRPCError({
          code: 'CONFLICT',
          message: `A track with slug "${input.slug}" already exists in this pipeline`,
        })
      }

      // Auto-set sortOrder
      const maxOrder = await ctx.prisma.track.aggregate({
        where: { pipelineId: input.pipelineId },
        _max: { sortOrder: true },
      })
      const sortOrder = (maxOrder._max.sortOrder ?? -1) + 1

      const { awardConfig, settingsJson, ...trackData } = input

      const result = await ctx.prisma.$transaction(async (tx) => {
        // Create the track
        const track = await tx.track.create({
          data: {
            pipelineId: input.pipelineId,
            name: trackData.name,
            slug: trackData.slug,
            kind: 'AWARD',
            routingMode: trackData.routingMode ?? null,
            decisionMode: trackData.decisionMode ?? 'JURY_VOTE',
            sortOrder,
            settingsJson: (settingsJson as Prisma.InputJsonValue) ?? undefined,
          },
        })

        // Create the linked SpecialAward
        const award = await tx.specialAward.create({
          data: {
            programId: pipeline.programId,
            name: awardConfig.name,
            description: awardConfig.description ?? null,
            criteriaText: awardConfig.criteriaText ?? null,
            scoringMode: awardConfig.scoringMode,
            maxRankedPicks: awardConfig.maxRankedPicks ?? null,
            useAiEligibility: awardConfig.useAiEligibility,
            trackId: track.id,
            sortOrder,
          },
        })

        await logAudit({
          prisma: tx,
          userId: ctx.user.id,
          action: 'CREATE_AWARD_TRACK',
          entityType: 'Track',
          entityId: track.id,
          detailsJson: {
            pipelineId: input.pipelineId,
            trackName: track.name,
            awardId: award.id,
            awardName: award.name,
          },
          ipAddress: ctx.ip,
          userAgent: ctx.userAgent,
        })

        return { track, award }
      })

      return result
    }),

  /**
   * Configure governance settings for an award track
   */
  configureGovernance: adminProcedure
    .input(
      z.object({
        trackId: z.string(),
        decisionMode: z.enum(['JURY_VOTE', 'AWARD_MASTER_DECISION', 'ADMIN_DECISION']).optional(),
        jurorIds: z.array(z.string()).optional(),
        votingStartAt: z.date().optional().nullable(),
        votingEndAt: z.date().optional().nullable(),
        scoringMode: z.enum(['PICK_WINNER', 'RANKED', 'SCORED']).optional(),
        maxRankedPicks: z.number().int().min(1).max(20).optional(),
      })
    )
    .mutation(async ({ ctx, input }) => {
      const track = await ctx.prisma.track.findUniqueOrThrow({
        where: { id: input.trackId },
        include: { specialAward: true },
      })

      if (track.kind !== 'AWARD') {
        throw new TRPCError({
          code: 'BAD_REQUEST',
          message: 'This track is not an AWARD track',
        })
      }

      if (!track.specialAward) {
        throw new TRPCError({
          code: 'NOT_FOUND',
          message: 'No award linked to this track',
        })
      }

      // Validate voting dates
      if (input.votingStartAt && input.votingEndAt) {
        if (input.votingEndAt <= input.votingStartAt) {
          throw new TRPCError({
            code: 'BAD_REQUEST',
            message: 'Voting end date must be after start date',
          })
        }
      }

      const result = await ctx.prisma.$transaction(async (tx) => {
        // Update track decision mode
        if (input.decisionMode) {
          await tx.track.update({
            where: { id: input.trackId },
            data: { decisionMode: input.decisionMode },
          })
        }

        // Update award config
        const awardUpdate: Record<string, unknown> = {}
        if (input.votingStartAt !== undefined) awardUpdate.votingStartAt = input.votingStartAt
        if (input.votingEndAt !== undefined) awardUpdate.votingEndAt = input.votingEndAt
        if (input.scoringMode) awardUpdate.scoringMode = input.scoringMode
        if (input.maxRankedPicks !== undefined) awardUpdate.maxRankedPicks = input.maxRankedPicks

        let updatedAward = track.specialAward
        if (Object.keys(awardUpdate).length > 0) {
          updatedAward = await tx.specialAward.update({
            where: { id: track.specialAward!.id },
            data: awardUpdate,
          })
        }

        // Manage jurors if provided
        if (input.jurorIds) {
          // Remove all existing jurors
          await tx.awardJuror.deleteMany({
            where: { awardId: track.specialAward!.id },
          })

          // Add new jurors
          if (input.jurorIds.length > 0) {
            await tx.awardJuror.createMany({
              data: input.jurorIds.map((userId) => ({
                awardId: track.specialAward!.id,
                userId,
              })),
              skipDuplicates: true,
            })
          }
        }

        await logAudit({
          prisma: tx,
          userId: ctx.user.id,
          action: 'CONFIGURE_AWARD_GOVERNANCE',
          entityType: 'Track',
          entityId: input.trackId,
          detailsJson: {
            awardId: track.specialAward!.id,
            decisionMode: input.decisionMode,
            jurorCount: input.jurorIds?.length,
            scoringMode: input.scoringMode,
          },
          ipAddress: ctx.ip,
          userAgent: ctx.userAgent,
        })

        return {
          track: { id: track.id, decisionMode: input.decisionMode ?? track.decisionMode },
          award: updatedAward,
          jurorsSet: input.jurorIds?.length ?? null,
        }
      })

      return result
    }),

  /**
   * Route projects to an award track (set eligibility)
   */
  routeProjects: adminProcedure
    .input(
      z.object({
        trackId: z.string(),
        projectIds: z.array(z.string()).min(1).max(500),
        eligible: z.boolean().default(true),
      })
    )
    .mutation(async ({ ctx, input }) => {
      const track = await ctx.prisma.track.findUniqueOrThrow({
        where: { id: input.trackId },
        include: { specialAward: true },
      })

      if (!track.specialAward) {
        throw new TRPCError({
          code: 'NOT_FOUND',
          message: 'No award linked to this track',
        })
      }

      const awardId = track.specialAward.id

      // Upsert eligibility records
      let createdCount = 0
      let updatedCount = 0

      await ctx.prisma.$transaction(async (tx) => {
        for (const projectId of input.projectIds) {
          const existing = await tx.awardEligibility.findUnique({
            where: { awardId_projectId: { awardId, projectId } },
          })

          if (existing) {
            await tx.awardEligibility.update({
              where: { id: existing.id },
              data: {
                eligible: input.eligible,
                method: 'MANUAL',
                overriddenBy: ctx.user.id,
                overriddenAt: new Date(),
              },
            })
            updatedCount++
          } else {
            await tx.awardEligibility.create({
              data: {
                awardId,
                projectId,
                eligible: input.eligible,
                method: 'MANUAL',
                overriddenBy: ctx.user.id,
                overriddenAt: new Date(),
              },
            })
            createdCount++
          }
        }

        // Also create ProjectStageState entries for routing through pipeline
        const firstStage = await tx.stage.findFirst({
          where: { trackId: input.trackId },
          orderBy: { sortOrder: 'asc' },
        })

        if (firstStage) {
          for (const projectId of input.projectIds) {
            await tx.projectStageState.upsert({
              where: {
                projectId_trackId_stageId: {
                  projectId,
                  trackId: input.trackId,
                  stageId: firstStage.id,
                },
              },
              create: {
                projectId,
                trackId: input.trackId,
                stageId: firstStage.id,
                state: input.eligible ? 'PENDING' : 'REJECTED',
              },
              update: {
                state: input.eligible ? 'PENDING' : 'REJECTED',
              },
            })
          }
        }

        await logAudit({
          prisma: tx,
          userId: ctx.user.id,
          action: 'ROUTE_PROJECTS_TO_AWARD',
          entityType: 'Track',
          entityId: input.trackId,
          detailsJson: {
            awardId,
            projectCount: input.projectIds.length,
            eligible: input.eligible,
            created: createdCount,
            updated: updatedCount,
          },
          ipAddress: ctx.ip,
          userAgent: ctx.userAgent,
        })
      })

      return { created: createdCount, updated: updatedCount, total: input.projectIds.length }
    }),

  /**
   * Finalize winners for an award (Award Master only)
   */
  finalizeWinners: awardMasterProcedure
    .input(
      z.object({
        trackId: z.string(),
        winnerProjectId: z.string(),
        override: z.boolean().default(false),
        reasonText: z.string().max(2000).optional(),
      })
    )
    .mutation(async ({ ctx, input }) => {
      const track = await ctx.prisma.track.findUniqueOrThrow({
        where: { id: input.trackId },
        include: { specialAward: true },
      })

      if (!track.specialAward) {
        throw new TRPCError({
          code: 'NOT_FOUND',
          message: 'No award linked to this track',
        })
      }

      const award = track.specialAward

      // Verify the winning project is eligible
      const eligibility = await ctx.prisma.awardEligibility.findUnique({
        where: {
          awardId_projectId: {
            awardId: award.id,
            projectId: input.winnerProjectId,
          },
        },
      })

      if (!eligibility || !eligibility.eligible) {
        throw new TRPCError({
          code: 'PRECONDITION_FAILED',
          message: 'Selected project is not eligible for this award',
        })
      }

      // Check if award already has a winner
      if (award.winnerProjectId && !input.override) {
        throw new TRPCError({
          code: 'CONFLICT',
          message: `Award already has a winner. Set override=true to change it.`,
        })
      }

      // Validate award is in VOTING_OPEN or CLOSED status (appropriate for finalization)
      if (!['VOTING_OPEN', 'CLOSED'].includes(award.status)) {
        throw new TRPCError({
          code: 'PRECONDITION_FAILED',
          message: `Award must be in VOTING_OPEN or CLOSED status to finalize. Current: ${award.status}`,
        })
      }

      const previousWinnerId = award.winnerProjectId

      const result = await ctx.prisma.$transaction(async (tx) => {
        const updated = await tx.specialAward.update({
          where: { id: award.id },
          data: {
            winnerProjectId: input.winnerProjectId,
            winnerOverridden: input.override,
            winnerOverriddenBy: input.override ? ctx.user.id : null,
            status: 'CLOSED',
          },
        })

        // Mark winner project as COMPLETED in the award track
        const firstStage = await tx.stage.findFirst({
          where: { trackId: input.trackId },
          orderBy: { sortOrder: 'asc' },
        })

        if (firstStage) {
          await tx.projectStageState.updateMany({
            where: {
              trackId: input.trackId,
              stageId: firstStage.id,
              projectId: input.winnerProjectId,
            },
            data: { state: 'COMPLETED' },
          })
        }

        // Record in decision audit
        await tx.decisionAuditLog.create({
          data: {
            eventType: 'award.winner_finalized',
            entityType: 'SpecialAward',
            entityId: award.id,
            actorId: ctx.user.id,
            detailsJson: {
              winnerProjectId: input.winnerProjectId,
              previousWinnerId,
              override: input.override,
              reasonText: input.reasonText,
            } as Prisma.InputJsonValue,
            snapshotJson: {
              awardName: award.name,
              previousStatus: award.status,
              previousWinner: previousWinnerId,
            } as Prisma.InputJsonValue,
          },
        })

        if (input.override && previousWinnerId) {
          await tx.overrideAction.create({
            data: {
              entityType: 'SpecialAward',
              entityId: award.id,
              previousValue: { winnerProjectId: previousWinnerId } as Prisma.InputJsonValue,
              newValueJson: { winnerProjectId: input.winnerProjectId } as Prisma.InputJsonValue,
              reasonCode: 'ADMIN_DISCRETION',
              reasonText: input.reasonText ?? null,
              actorId: ctx.user.id,
            },
          })
        }

        await logAudit({
          prisma: tx,
          userId: ctx.user.id,
          action: 'AWARD_WINNER_FINALIZED',
          entityType: 'SpecialAward',
          entityId: award.id,
          detailsJson: {
            awardName: award.name,
            winnerProjectId: input.winnerProjectId,
            override: input.override,
            previousWinnerId,
          },
          ipAddress: ctx.ip,
          userAgent: ctx.userAgent,
        })

        return updated
      })

      return result
    }),

  /**
   * Get projects routed to an award track with eligibility and votes
   */
  getTrackProjects: protectedProcedure
    .input(
      z.object({
        trackId: z.string(),
        eligibleOnly: z.boolean().default(false),
      })
    )
    .query(async ({ ctx, input }) => {
      const track = await ctx.prisma.track.findUniqueOrThrow({
        where: { id: input.trackId },
        include: { specialAward: true },
      })

      if (!track.specialAward) {
        throw new TRPCError({
          code: 'NOT_FOUND',
          message: 'No award linked to this track',
        })
      }

      const awardId = track.specialAward.id

      const eligibilityWhere: Prisma.AwardEligibilityWhereInput = {
        awardId,
      }
      if (input.eligibleOnly) {
        eligibilityWhere.eligible = true
      }

      const eligibilities = await ctx.prisma.awardEligibility.findMany({
        where: eligibilityWhere,
        include: {
          project: {
            select: {
              id: true,
              title: true,
              teamName: true,
              tags: true,
              description: true,
              status: true,
            },
          },
        },
        orderBy: { createdAt: 'asc' },
      })

      // Get vote counts per project
      const projectIds = eligibilities.map((e) => e.projectId)
      const voteSummary =
        projectIds.length > 0
          ? await ctx.prisma.awardVote.groupBy({
              by: ['projectId'],
              where: { awardId, projectId: { in: projectIds } },
              _count: true,
            })
          : []

      const voteMap = new Map(
        voteSummary.map((v) => [v.projectId, v._count])
      )

      return {
        trackId: input.trackId,
        awardId,
        awardName: track.specialAward.name,
        winnerProjectId: track.specialAward.winnerProjectId,
        status: track.specialAward.status,
        projects: eligibilities.map((e) => ({
          ...e,
          voteCount: voteMap.get(e.projectId) ?? 0,
          isWinner: e.projectId === track.specialAward!.winnerProjectId,
        })),
      }
    }),
})