import { CreateOrgUnitSchema, UpdateOrgUnitSchema } from "@capakraken/shared";
import { TRPCError } from "@trpc/server";
import { z } from "zod";
import { findUniqueOrThrow } from "../db/helpers.js";
import { createAuditEntry } from "../lib/audit.js";
import {
  adminProcedure,
  createTRPCRouter,
  protectedProcedure,
  resourceOverviewProcedure,
} from "../trpc.js";

import type { OrgUnitTree } from "@capakraken/shared";

interface FlatOrgUnit {
  id: string;
  name: string;
  shortName: string | null;
  level: number;
  parentId: string | null;
  sortOrder: number;
  isActive: boolean;
  createdAt: Date;
  updatedAt: Date;
}

function buildTree(flatItems: FlatOrgUnit[], parentId: string | null = null): OrgUnitTree[] {
  return flatItems
    .filter((item) => item.parentId === parentId)
    .sort((a, b) => a.sortOrder - b.sortOrder || a.name.localeCompare(b.name))
    .map((item) => ({
      ...item,
      children: buildTree(flatItems, item.id),
    }));
}

export const orgUnitRouter = createTRPCRouter({
  list: resourceOverviewProcedure
    .input(
      z.object({
        level: z.number().int().min(5).max(7).optional(),
        parentId: z.string().optional(),
        isActive: z.boolean().optional(),
      }).optional(),
    )
    .query(async ({ ctx, input }) => {
      return ctx.db.orgUnit.findMany({
        where: {
          ...(input?.level !== undefined ? { level: input.level } : {}),
          ...(input?.parentId !== undefined ? { parentId: input.parentId } : {}),
          ...(input?.isActive !== undefined ? { isActive: input.isActive } : {}),
        },
        orderBy: [{ level: "asc" }, { sortOrder: "asc" }, { name: "asc" }],
      });
    }),

  getTree: resourceOverviewProcedure
    .input(z.object({ isActive: z.boolean().optional() }).optional())
    .query(async ({ ctx, input }) => {
      const all = await ctx.db.orgUnit.findMany({
        where: {
          ...(input?.isActive !== undefined ? { isActive: input.isActive } : {}),
        },
        orderBy: [{ sortOrder: "asc" }, { name: "asc" }],
      });
      return buildTree(all);
    }),

  getById: resourceOverviewProcedure
    .input(z.object({ id: z.string() }))
    .query(async ({ ctx, input }) => {
      const unit = await findUniqueOrThrow(
        ctx.db.orgUnit.findUnique({
          where: { id: input.id },
          include: {
            parent: true,
            children: { orderBy: { sortOrder: "asc" } },
            _count: { select: { resources: true } },
          },
        }),
        "Org unit",
      );
      return unit;
    }),

  resolveByIdentifier: protectedProcedure
    .input(z.object({ identifier: z.string().trim().min(1) }))
    .query(async ({ ctx, input }) => {
      const identifier = input.identifier.trim();
      const select = {
        id: true,
        name: true,
        shortName: true,
        level: true,
        isActive: true,
      } as const;

      let unit = await ctx.db.orgUnit.findUnique({
        where: { id: identifier },
        select,
      });

      if (!unit) {
        unit = await ctx.db.orgUnit.findFirst({
          where: { name: { equals: identifier, mode: "insensitive" } },
          select,
        });
      }

      if (!unit) {
        unit = await ctx.db.orgUnit.findFirst({
          where: { shortName: { equals: identifier, mode: "insensitive" } },
          select,
        });
      }

      if (!unit) {
        unit = await ctx.db.orgUnit.findFirst({
          where: {
            OR: [
              { name: { contains: identifier, mode: "insensitive" } },
              { shortName: { contains: identifier, mode: "insensitive" } },
            ],
          },
          select,
        });
      }

      if (!unit) {
        throw new TRPCError({ code: "NOT_FOUND", message: `Org unit not found: ${identifier}` });
      }

      return unit;
    }),

  getByIdentifier: resourceOverviewProcedure
    .input(z.object({ identifier: z.string().trim().min(1) }))
    .query(async ({ ctx, input }) => {
      const identifier = input.identifier.trim();
      let unit = await ctx.db.orgUnit.findUnique({
        where: { id: identifier },
        include: { _count: { select: { resources: true } } },
      });

      if (!unit) {
        unit = await ctx.db.orgUnit.findFirst({
          where: { name: { equals: identifier, mode: "insensitive" } },
          include: { _count: { select: { resources: true } } },
        });
      }

      if (!unit) {
        unit = await ctx.db.orgUnit.findFirst({
          where: { shortName: { equals: identifier, mode: "insensitive" } },
          include: { _count: { select: { resources: true } } },
        });
      }

      if (!unit) {
        unit = await ctx.db.orgUnit.findFirst({
          where: {
            OR: [
              { name: { contains: identifier, mode: "insensitive" } },
              { shortName: { contains: identifier, mode: "insensitive" } },
            ],
          },
          include: { _count: { select: { resources: true } } },
        });
      }

      if (!unit) {
        throw new TRPCError({ code: "NOT_FOUND", message: `Org unit not found: ${identifier}` });
      }

      return unit;
    }),

  create: adminProcedure
    .input(CreateOrgUnitSchema)
    .mutation(async ({ ctx, input }) => {
      if (input.parentId) {
        const parent = await findUniqueOrThrow(
          ctx.db.orgUnit.findUnique({ where: { id: input.parentId } }),
          "Parent org unit",
        );
        if (parent.level >= input.level) {
          throw new TRPCError({
            code: "BAD_REQUEST",
            message: `Child level (${input.level}) must be greater than parent level (${parent.level})`,
          });
        }
      }

      const created = await ctx.db.orgUnit.create({
        data: {
          name: input.name,
          ...(input.shortName !== undefined ? { shortName: input.shortName } : {}),
          level: input.level,
          ...(input.parentId ? { parentId: input.parentId } : {}),
          sortOrder: input.sortOrder,
        },
      });

      void createAuditEntry({
        db: ctx.db,
        entityType: "OrgUnit",
        entityId: created.id,
        entityName: created.name,
        action: "CREATE",
        userId: ctx.dbUser?.id,
        after: created as unknown as Record<string, unknown>,
        source: "ui",
      });

      return created;
    }),

  update: adminProcedure
    .input(z.object({ id: z.string(), data: UpdateOrgUnitSchema }))
    .mutation(async ({ ctx, input }) => {
      const existing = await findUniqueOrThrow(
        ctx.db.orgUnit.findUnique({ where: { id: input.id } }),
        "Org unit",
      );

      const before = existing as unknown as Record<string, unknown>;

      const updated = await ctx.db.orgUnit.update({
        where: { id: input.id },
        data: {
          ...(input.data.name !== undefined ? { name: input.data.name } : {}),
          ...(input.data.shortName !== undefined ? { shortName: input.data.shortName } : {}),
          ...(input.data.sortOrder !== undefined ? { sortOrder: input.data.sortOrder } : {}),
          ...(input.data.isActive !== undefined ? { isActive: input.data.isActive } : {}),
          ...(input.data.parentId !== undefined ? { parentId: input.data.parentId } : {}),
        },
      });

      void createAuditEntry({
        db: ctx.db,
        entityType: "OrgUnit",
        entityId: updated.id,
        entityName: updated.name,
        action: "UPDATE",
        userId: ctx.dbUser?.id,
        before,
        after: updated as unknown as Record<string, unknown>,
        source: "ui",
      });

      return updated;
    }),

  deactivate: adminProcedure
    .input(z.object({ id: z.string() }))
    .mutation(async ({ ctx, input }) => {
      const updated = await ctx.db.orgUnit.update({
        where: { id: input.id },
        data: { isActive: false },
      });

      void createAuditEntry({
        db: ctx.db,
        entityType: "OrgUnit",
        entityId: updated.id,
        entityName: updated.name,
        action: "UPDATE",
        userId: ctx.dbUser?.id,
        before: { isActive: true },
        after: { isActive: false },
        source: "ui",
        summary: "Deactivated OrgUnit",
      });

      return updated;
    }),
});