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

// ─── Shared zod schemas ──────────────────────────────────────────────────────

const dietaryTags = z.array(
  z.enum(['VEGETARIAN', 'VEGAN', 'GLUTEN_FREE', 'PESCATARIAN']),
)

const allergens = z.array(
  z.enum([
    'GLUTEN', 'CRUSTACEANS', 'EGGS', 'FISH', 'PEANUTS', 'SOYBEANS', 'MILK',
    'TREE_NUTS', 'CELERY', 'MUSTARD', 'SESAME', 'SULPHITES', 'LUPIN', 'MOLLUSCS',
  ]),
)

// ─── Router ──────────────────────────────────────────────────────────────────

export const lunchRouter = router({
  /**
   * Get-or-create the LunchEvent for a program. Lazy creation mirrors
   * the hotel pattern: callers don't have to know whether the row
   * already exists.
   */
  getEvent: adminProcedure
    .input(z.object({ programId: z.string() }))
    .query(async ({ ctx, input }) => {
      const existing = await ctx.prisma.lunchEvent.findUnique({
        where: { programId: input.programId },
      })
      if (existing) return existing
      return ctx.prisma.lunchEvent.create({ data: { programId: input.programId } })
    }),

  // ─── Dish CRUD ────────────────────────────────────────────────────────────

  listDishes: adminProcedure
    .input(z.object({ lunchEventId: z.string() }))
    .query(({ ctx, input }) =>
      ctx.prisma.dish.findMany({
        where: { lunchEventId: input.lunchEventId },
        orderBy: [{ sortOrder: 'asc' }, { createdAt: 'asc' }],
      }),
    ),

  createDish: adminProcedure
    .input(
      z.object({
        lunchEventId: z.string(),
        name: z.string().min(1).max(200),
        dietaryTags,
        sortOrder: z.number().int().optional(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const dish = await ctx.prisma.dish.create({
        data: {
          lunchEventId: input.lunchEventId,
          name: input.name,
          dietaryTags: input.dietaryTags,
          sortOrder: input.sortOrder ?? 0,
        },
      })
      await logAudit({
        prisma: ctx.prisma,
        userId: ctx.user.id,
        action: 'LUNCH_DISH_CREATED',
        entityType: 'Dish',
        entityId: dish.id,
        detailsJson: { name: dish.name, dietaryTags: dish.dietaryTags },
      })
      return dish
    }),

  updateDish: adminProcedure
    .input(
      z.object({
        dishId: z.string(),
        name: z.string().min(1).max(200).optional(),
        dietaryTags: dietaryTags.optional(),
        sortOrder: z.number().int().optional(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const { dishId, ...patch } = input
      const dish = await ctx.prisma.dish.update({ where: { id: dishId }, data: patch })
      await logAudit({
        prisma: ctx.prisma,
        userId: ctx.user.id,
        action: 'LUNCH_DISH_UPDATED',
        entityType: 'Dish',
        entityId: dish.id,
        detailsJson: patch as Record<string, unknown>,
      })
      return dish
    }),

  deleteDish: adminProcedure
    .input(z.object({ dishId: z.string() }))
    .mutation(async ({ ctx, input }) => {
      const dish = await ctx.prisma.dish.delete({ where: { id: input.dishId } })
      await logAudit({
        prisma: ctx.prisma,
        userId: ctx.user.id,
        action: 'LUNCH_DISH_DELETED',
        entityType: 'Dish',
        entityId: dish.id,
        detailsJson: { name: dish.name },
      })
      return { ok: true as const }
    }),

  reorderDishes: adminProcedure
    .input(
      z.object({
        ordered: z.array(
          z.object({ dishId: z.string(), sortOrder: z.number().int() }),
        ),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      await ctx.prisma.$transaction(
        input.ordered.map(({ dishId, sortOrder }) =>
          ctx.prisma.dish.update({ where: { id: dishId }, data: { sortOrder } }),
        ),
      )
      return { ok: true as const }
    }),

  // ─── External attendees CRUD ─────────────────────────────────────────────

  listExternals: adminProcedure
    .input(z.object({ lunchEventId: z.string() }))
    .query(({ ctx, input }) =>
      ctx.prisma.externalAttendee.findMany({
        where: { lunchEventId: input.lunchEventId },
        orderBy: { createdAt: 'asc' },
        include: { project: { select: { id: true, title: true } } },
      }),
    ),

  createExternal: adminProcedure
    .input(
      z.object({
        lunchEventId: z.string(),
        name: z.string().min(1).max(200),
        email: z.string().email().optional(),
        projectId: z.string().nullable().optional(),
        roleNote: z.string().max(500).optional(),
        dishId: z.string().nullable().optional(),
        allergens: allergens.optional(),
        allergenOther: z.string().max(500).optional(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const ext = await ctx.prisma.externalAttendee.create({
        data: {
          lunchEventId: input.lunchEventId,
          name: input.name,
          email: input.email,
          projectId: input.projectId ?? null,
          roleNote: input.roleNote,
          dishId: input.dishId ?? null,
          allergens: input.allergens ?? [],
          allergenOther: input.allergenOther,
        },
      })
      await logAudit({
        prisma: ctx.prisma,
        userId: ctx.user.id,
        action: 'LUNCH_EXTERNAL_CREATED',
        entityType: 'ExternalAttendee',
        entityId: ext.id,
        detailsJson: { name: ext.name, projectId: ext.projectId },
      })
      return ext
    }),

  updateExternal: adminProcedure
    .input(
      z.object({
        externalId: z.string(),
        name: z.string().min(1).max(200).optional(),
        email: z.string().email().nullable().optional(),
        projectId: z.string().nullable().optional(),
        roleNote: z.string().max(500).nullable().optional(),
        dishId: z.string().nullable().optional(),
        allergens: allergens.optional(),
        allergenOther: z.string().max(500).nullable().optional(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const { externalId, ...patch } = input
      const ext = await ctx.prisma.externalAttendee.update({
        where: { id: externalId },
        data: patch,
      })
      await logAudit({
        prisma: ctx.prisma,
        userId: ctx.user.id,
        action: 'LUNCH_EXTERNAL_UPDATED',
        entityType: 'ExternalAttendee',
        entityId: ext.id,
        detailsJson: patch as Record<string, unknown>,
      })
      return ext
    }),

  deleteExternal: adminProcedure
    .input(z.object({ externalId: z.string() }))
    .mutation(async ({ ctx, input }) => {
      const ext = await ctx.prisma.externalAttendee.delete({
        where: { id: input.externalId },
      })
      await logAudit({
        prisma: ctx.prisma,
        userId: ctx.user.id,
        action: 'LUNCH_EXTERNAL_DELETED',
        entityType: 'ExternalAttendee',
        entityId: ext.id,
        detailsJson: { name: ext.name },
      })
      return { ok: true as const }
    }),

  // ─── Mixed-permission picker ─────────────────────────────────────────────

  /**
   * Upsert a MemberLunchPick. Permission:
   *  - admin (SUPER_ADMIN / PROGRAM_ADMIN): always allowed, no deadline cap
   *  - team lead of the parent project: allowed before deadline
   *  - the AttendingMember.userId themselves: allowed before deadline
   *  - everyone else: FORBIDDEN
   * Audit-logged with the actor role (SELF / TEAM_LEAD / ADMIN).
   */
  upsertPick: protectedProcedure
    .input(
      z.object({
        attendingMemberId: z.string(),
        dishId: z.string().nullable(),
        allergens,
        allergenOther: z.string().max(500).nullable(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const am = await ctx.prisma.attendingMember.findUnique({
        where: { id: input.attendingMemberId },
        include: {
          confirmation: {
            select: {
              project: {
                select: {
                  id: true,
                  programId: true,
                  teamMembers: { select: { userId: true, role: true } },
                },
              },
            },
          },
          lunchPick: true,
        },
      })
      if (!am) {
        throw new TRPCError({
          code: 'NOT_FOUND',
          message: 'Attending member not found',
        })
      }

      const userId = ctx.user.id
      const userRole = ctx.user.role
      const isAdmin =
        userRole === 'SUPER_ADMIN' || userRole === 'PROGRAM_ADMIN'
      const isSelf = am.userId === userId
      const isLead = am.confirmation.project.teamMembers.some(
        (tm) => tm.userId === userId && tm.role === 'LEAD',
      )
      if (!isAdmin && !isSelf && !isLead) {
        throw new TRPCError({
          code: 'FORBIDDEN',
          message: 'Not allowed to edit this pick',
        })
      }

      // Cutoff check (admins skip)
      if (!isAdmin) {
        const event = await ctx.prisma.lunchEvent.findUnique({
          where: { programId: am.confirmation.project.programId },
          select: { eventAt: true, changeCutoffHours: true },
        })
        if (event?.eventAt) {
          const deadline = new Date(
            event.eventAt.getTime() - event.changeCutoffHours * 3_600_000,
          )
          if (new Date() > deadline) {
            throw new TRPCError({
              code: 'PRECONDITION_FAILED',
              message: 'Past lunch change deadline. Contact an admin.',
            })
          }
        }
      }

      const actorRole: 'SELF' | 'TEAM_LEAD' | 'ADMIN' = isAdmin
        ? 'ADMIN'
        : isLead && !isSelf
          ? 'TEAM_LEAD'
          : 'SELF'

      const pick = await ctx.prisma.memberLunchPick.upsert({
        where: { attendingMemberId: input.attendingMemberId },
        create: {
          attendingMemberId: input.attendingMemberId,
          dishId: input.dishId,
          allergens: input.allergens,
          allergenOther: input.allergenOther,
          pickedAt: input.dishId ? new Date() : null,
        },
        update: {
          dishId: input.dishId,
          allergens: input.allergens,
          allergenOther: input.allergenOther,
          pickedAt: input.dishId ? new Date() : null,
        },
      })

      await logAudit({
        prisma: ctx.prisma,
        userId,
        action: 'LUNCH_PICK_UPDATED',
        entityType: 'MemberLunchPick',
        entityId: pick.id,
        detailsJson: {
          actorRole,
          dishId: input.dishId,
          allergenCount: input.allergens.length,
        },
      })
      return pick
    }),

  /** Patch any subset of LunchEvent config fields. Audit-logged. */
  updateEvent: adminProcedure
    .input(
      z.object({
        programId: z.string(),
        enabled: z.boolean().optional(),
        eventAt: z.date().nullable().optional(),
        endAt: z.date().nullable().optional(),
        venue: z.string().nullable().optional(),
        notes: z.string().nullable().optional(),
        changeCutoffHours: z.number().int().min(0).max(720).optional(),
        reminderHoursBeforeDeadline: z
          .number()
          .int()
          .min(0)
          .max(720)
          .nullable()
          .optional(),
        cronEnabled: z.boolean().optional(),
        extraRecipients: z.array(z.string().email()).optional(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const { programId, ...patch } = input
      // Lazy-create before patching so updateEvent doubles as "create + update"
      await ctx.prisma.lunchEvent.upsert({
        where: { programId },
        create: { programId },
        update: {},
      })
      const updated = await ctx.prisma.lunchEvent.update({
        where: { programId },
        data: patch,
      })
      await logAudit({
        prisma: ctx.prisma,
        userId: ctx.user.id,
        action: 'LUNCH_EVENT_UPDATED',
        entityType: 'LunchEvent',
        entityId: updated.id,
        detailsJson: patch as Record<string, unknown>,
      })
      return updated
    }),
})