import { CreateClientSchema, UpdateClientSchema } from "@capakraken/shared";
import { z } from "zod";
import { findUniqueOrThrow } from "../db/helpers.js";
import { createAuditEntry } from "../lib/audit.js";
import type { TRPCContext } from "../trpc.js";
import {
  assertClientCodeAvailable,
  assertClientDeletable,
  buildClientCreateData,
  buildClientListWhere,
  buildClientTree,
  buildClientUpdateData,
  findClientByIdentifier,
} from "./client-support.js";

type ClientProcedureContext = Pick<TRPCContext, "db" | "dbUser">;

type ClientIdentifierReadModel = {
  id: string;
  name: string;
  code: string | null;
  parentId: string | null;
  isActive: boolean;
};

type ClientDetailReadModel = ClientIdentifierReadModel & {
  sortOrder: number;
  tags: string[];
  createdAt: Date;
  updatedAt: Date;
  _count: {
    projects: number;
    children: number;
  };
};

function withAuditUser(userId: string | undefined) {
  return userId ? { userId } : {};
}

export const clientIdInputSchema = z.object({ id: z.string() });

export const clientIdentifierInputSchema = z.object({
  identifier: z.string().trim().min(1),
});

export const clientListInputSchema = z
  .object({
    parentId: z.string().nullable().optional(),
    isActive: z.boolean().optional(),
    search: z.string().optional(),
  })
  .optional();

export const clientTreeInputSchema = z
  .object({
    isActive: z.boolean().optional(),
  })
  .optional();

export const clientUpdateInputSchema = z.object({
  id: z.string(),
  data: UpdateClientSchema,
});

export const clientBatchSortOrderInputSchema = z.array(
  z.object({
    id: z.string(),
    sortOrder: z.number().int(),
  }),
);

type ClientIdInput = z.infer<typeof clientIdInputSchema>;
type ClientIdentifierInput = z.infer<typeof clientIdentifierInputSchema>;
type ClientListInput = z.infer<typeof clientListInputSchema>;
type ClientTreeInput = z.infer<typeof clientTreeInputSchema>;
type ClientCreateInput = z.infer<typeof CreateClientSchema>;
type ClientUpdateInput = z.infer<typeof clientUpdateInputSchema>;
type ClientBatchSortOrderInput = z.infer<typeof clientBatchSortOrderInputSchema>;

export async function listClients(ctx: ClientProcedureContext, input: ClientListInput) {
  return ctx.db.client.findMany({
    where: buildClientListWhere(input ?? {}),
    include: { _count: { select: { children: true, projects: true } } },
    orderBy: [{ sortOrder: "asc" }, { name: "asc" }],
  });
}

export async function getClientTree(ctx: ClientProcedureContext, input: ClientTreeInput) {
  const all = await ctx.db.client.findMany({
    where: {
      ...(input?.isActive !== undefined ? { isActive: input.isActive } : {}),
    },
    orderBy: [{ sortOrder: "asc" }, { name: "asc" }],
  });

  return buildClientTree(all);
}

export async function getClientById(ctx: ClientProcedureContext, input: ClientIdInput) {
  return findUniqueOrThrow(
    ctx.db.client.findUnique({
      where: { id: input.id },
      include: {
        parent: true,
        children: { orderBy: { sortOrder: "asc" } },
        _count: { select: { projects: true, children: true } },
      },
    }),
    "Client",
  );
}

export async function resolveClientByIdentifier(
  ctx: ClientProcedureContext,
  input: ClientIdentifierInput,
) {
  return findClientByIdentifier<ClientIdentifierReadModel>(ctx.db, input.identifier, {
    select: {
      id: true,
      name: true,
      code: true,
      parentId: true,
      isActive: true,
    },
  });
}

export async function getClientByIdentifier(
  ctx: ClientProcedureContext,
  input: ClientIdentifierInput,
) {
  return findClientByIdentifier<ClientDetailReadModel>(ctx.db, input.identifier, {
    include: { _count: { select: { projects: true, children: true } } },
  });
}

export async function createClient(ctx: ClientProcedureContext, input: ClientCreateInput) {
  if (input.parentId) {
    await findUniqueOrThrow(
      ctx.db.client.findUnique({ where: { id: input.parentId } }),
      "Parent client",
    );
  }

  if (input.code) {
    await assertClientCodeAvailable(ctx.db, input.code);
  }

  const created = await ctx.db.client.create({
    data: buildClientCreateData(input),
  });

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

  return created;
}

export async function updateClient(ctx: ClientProcedureContext, input: ClientUpdateInput) {
  const existing = await findUniqueOrThrow(
    ctx.db.client.findUnique({ where: { id: input.id } }),
    "Client",
  );

  if (input.data.code && input.data.code !== existing.code) {
    await assertClientCodeAvailable(ctx.db, input.data.code, existing.id);
  }

  const before = existing as unknown as Record<string, unknown>;
  const updated = await ctx.db.client.update({
    where: { id: input.id },
    data: buildClientUpdateData(input.data),
  });

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

  return updated;
}

export async function deactivateClient(ctx: ClientProcedureContext, input: ClientIdInput) {
  const updated = await ctx.db.client.update({
    where: { id: input.id },
    data: { isActive: false },
  });

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

  return updated;
}

export async function deleteClient(ctx: ClientProcedureContext, input: ClientIdInput) {
  const client = await findUniqueOrThrow(
    ctx.db.client.findUnique({
      where: { id: input.id },
      include: { _count: { select: { projects: true, children: true } } },
    }),
    "Client",
  );

  assertClientDeletable(client);
  await ctx.db.client.delete({ where: { id: input.id } });

  void createAuditEntry({
    db: ctx.db,
    entityType: "Client",
    entityId: client.id,
    entityName: client.name,
    action: "DELETE",
    ...withAuditUser(ctx.dbUser?.id),
    before: client as unknown as Record<string, unknown>,
    source: "ui",
  });

  return client;
}

export async function batchUpdateClientSortOrder(
  ctx: ClientProcedureContext,
  input: ClientBatchSortOrderInput,
) {
  await ctx.db.$transaction(
    input.map((item) =>
      ctx.db.client.update({
        where: { id: item.id },
        data: { sortOrder: item.sortOrder },
      }),
    ),
  );

  for (const item of input) {
    void createAuditEntry({
      db: ctx.db,
      entityType: "Client",
      entityId: item.id,
      action: "UPDATE",
      ...withAuditUser(ctx.dbUser?.id),
      after: { sortOrder: item.sortOrder },
      source: "ui",
      summary: "Updated sort order",
    });
  }

  return { ok: true };
}
