import type { FastifyInstance } from 'fastify';
import { z } from 'zod';
import { CreditKind, InactiveReason } from '@prisma/client';
import { requireAdmin, requireAuth, requireEditor } from '../auth/guard.js';
import { forbidden } from '../errors.js';
import { prisma } from '../db.js';
import {
  addMember,
  createCharacter,
  deactivateCharacter,
  listMembers,
  removeMember,
  reviveDeadCharacter,
  reactivateFree,
  reactivatePaid,
  redesignCharacter,
  revertCharacter,
  updateCharacter,
  deactivateMember,
  reactivateMember,
  redesignMembership,
} from '../services/characters.js';
import { parseThreadId } from '../lib/forum.js';
import { linkThreadToCharacter } from '../services/forum.js';
import { badRequest } from '../errors.js';
import { contextOf, idParam, optionalNote, parseWith } from './helpers.js';

/** Hakt den zugehörigen Forums-Thread ab, wenn einer angegeben wurde. */
async function linkThread(
  threadInput: string | undefined,
  characterId: number,
  classification: 'NEW_CC' | 'REDESIGN',
  ctx: ReturnType<typeof contextOf>,
): Promise<void> {
  if (!threadInput?.trim()) return;

  const threadId = parseThreadId(threadInput);
  if (threadId === null) {
    throw badRequest('INVALID_THREAD', 'Der Thread-Link konnte nicht gelesen werden');
  }
  await linkThreadToCharacter(threadId, characterId, classification, ctx);
}

const redesignKind = z.enum([CreditKind.REDESIGN_PAID, CreditKind.REDESIGN_KULANZ]);
const reviveKind = z.enum([CreditKind.CC, CreditKind.REDESIGN_PAID, CreditKind.REDESIGN_KULANZ]);

export async function characterRoutes(app: FastifyInstance): Promise<void> {
  app.post('/api/players/:id/characters', { preHandler: requireEditor }, async (request, reply) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({
        name: z.string().trim().min(1).max(160),
        loreText: z.string().trim().max(5000).optional(),
        note: optionalNote,
        forumThread: z.string().trim().max(300).optional(),
      }),
      request.body,
    );
    const ctx = contextOf(request);
    const result = await createCharacter(id, body, ctx);
    await linkThread(body.forumThread, result.character.id, 'NEW_CC', ctx);
    reply.code(201);
    return result;
  });

  app.patch('/api/characters/:id', { preHandler: requireEditor }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({
        name: z.string().trim().min(1).max(160).optional(),
        loreText: z.string().trim().max(5000).nullable().optional(),
      }),
      request.body,
    );
    return updateCharacter(id, body, contextOf(request));
  });

  app.post('/api/characters/:id/redesign', { preHandler: requireEditor }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({
        name: z.string().trim().min(1).max(160),
        loreText: z.string().trim().max(5000).optional(),
        useKind: redesignKind,
        note: optionalNote,
        forumThread: z.string().trim().max(300).optional(),
      }),
      request.body,
    );
    const ctx = contextOf(request);
    const result = await redesignCharacter(id, body, ctx);
    await linkThread(body.forumThread, result.character.id, 'REDESIGN', ctx);
    return result;
  });

  app.post('/api/characters/:id/deactivate', { preHandler: requireEditor }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({
        reason: z.enum([
          InactiveReason.PLAYER_INACTIVITY,
          InactiveReason.OTHER,
          InactiveReason.NO_FREE_CLAIM,
          InactiveReason.DEAD,
        ]),
        note: optionalNote,
      }),
      request.body,
    );
    return deactivateCharacter(id, body.reason, contextOf(request), body.note);
  });

  app.post('/api/characters/:id/reactivate-free', { preHandler: requireEditor }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    return reactivateFree(id, contextOf(request));
  });

  app.post('/api/characters/:id/reactivate-paid', { preHandler: requireEditor }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({ useKind: reviveKind, note: optionalNote }),
      request.body,
    );
    return reactivatePaid(id, body.useKind, contextOf(request), body.note);
  });

  /**
   * Rückkehr eines im Rollenspiel gestorbenen CCs. Ausnahmeentscheidung,
   * deshalb Administratoren vorbehalten und nur mit Begründung.
   */
  app.post('/api/characters/:id/revive-dead', { preHandler: requireAdmin }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({
        reason: z.string().trim().min(1, 'Eine Begründung ist Pflicht').max(500),
        useKind: reviveKind.optional(),
      }),
      request.body,
    );
    return reviveDeadCharacter(id, body, contextOf(request));
  });

  // --- Gruppen-CCs ---

  app.get('/api/characters/:id/members', { preHandler: requireAuth }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    return { items: await listMembers(id) };
  });

  app.post('/api/characters/:id/members', { preHandler: requireEditor }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({
        playerId: z.number().int().positive(),
        useKind: z.enum([CreditKind.CC, CreditKind.REDESIGN_PAID, CreditKind.REDESIGN_KULANZ]),
        /// Der eigene CC, den der Spieler dafür aufgibt. Pflicht, sobald der
        /// Platz über ein Redesign bezahlt wird.
        predecessorId: z.number().int().positive().optional(),
        note: optionalNote,
      }),
      request.body,
    );
    return addMember(
      id,
      body.playerId,
      { useKind: body.useKind, predecessorId: body.predecessorId, note: body.note },
      contextOf(request),
    );
  });

  /**
   * Der Anteil eines Spielers an einem Gruppen-CC wird redesignt: er steigt
   * aus, bekommt einen eigenen CC, die Gruppe läuft weiter.
   */
  app.post(
    '/api/characters/:id/members/:playerId/redesign',
    { preHandler: requireEditor },
    async (request) => {
      const params = parseWith(
        z.object({
          id: z.coerce.number().int().positive(),
          playerId: z.coerce.number().int().positive(),
        }),
        request.params,
      );
      const body = parseWith(
        z.object({
          name: z.string().trim().min(1).max(160),
          loreText: z.string().trim().max(5000).optional(),
          useKind: z.enum([CreditKind.REDESIGN_PAID, CreditKind.REDESIGN_KULANZ]),
          note: optionalNote,
        }),
        request.body,
      );
      return redesignMembership(params.id, params.playerId, body, contextOf(request));
    },
  );

  /** Ein einzelnes Mitglied fällt aus, der CC bleibt bestehen. */
  app.post(
    '/api/characters/:id/members/:playerId/deactivate',
    { preHandler: requireEditor },
    async (request) => {
      const params = parseWith(
        z.object({
          id: z.coerce.number().int().positive(),
          playerId: z.coerce.number().int().positive(),
        }),
        request.params,
      );
      const body = parseWith(
        z.object({
          reason: z.enum([
            InactiveReason.PLAYER_INACTIVITY,
            InactiveReason.OTHER,
            InactiveReason.NO_FREE_CLAIM,
            InactiveReason.DEAD,
          ]),
          note: optionalNote,
        }),
        request.body,
      );

      // Ein Tod im Rollenspiel ist eine Ausnahmeentscheidung, genau wie beim
      // ganzen CC - und bleibt deshalb Administratoren vorbehalten.
      if (body.reason === InactiveReason.DEAD && request.user?.role !== 'ADMIN') {
        throw forbidden('Einen Tod im Rollenspiel trägt nur ein Administrator ein');
      }

      return deactivateMember(
        params.id,
        params.playerId,
        body.reason,
        contextOf(request),
        body.note,
      );
    },
  );

  /** Rückkehr eines ausgefallenen Mitglieds. */
  app.post(
    '/api/characters/:id/members/:playerId/reactivate',
    { preHandler: requireEditor },
    async (request) => {
      const params = parseWith(
        z.object({
          id: z.coerce.number().int().positive(),
          playerId: z.coerce.number().int().positive(),
        }),
        request.params,
      );
      const body = parseWith(
        z.object({
          useKind: reviveKind.optional(),
          reason: z.string().trim().max(500).optional(),
        }),
        request.body ?? {},
      );

      // Wer im Rollenspiel gestorben ist, kehrt nur durch einen Administrator
      // zurück. Geprüft wird am tatsächlichen Grund, nicht an der Eingabe.
      const mitglied = await prisma.characterMember.findUnique({
        where: { characterId_playerId: { characterId: params.id, playerId: params.playerId } },
        select: { inactiveReason: true },
      });
      if (mitglied?.inactiveReason === InactiveReason.DEAD && request.user?.role !== 'ADMIN') {
        throw forbidden('Über die Rückkehr eines Gestorbenen entscheidet ein Administrator');
      }

      return reactivateMember(params.id, params.playerId, body, contextOf(request));
    },
  );

  app.delete('/api/characters/:id/members/:playerId', { preHandler: requireEditor }, async (request) => {
    const params = parseWith(
      z.object({
        id: z.coerce.number().int().positive(),
        playerId: z.coerce.number().int().positive(),
      }),
      request.params,
    );
    const body = parseWith(z.object({ note: optionalNote }), request.body ?? {});
    return removeMember(params.id, params.playerId, body.note, contextOf(request));
  });

  app.post('/api/characters/:id/revert', { preHandler: requireEditor }, async (request) => {
    const { id } = parseWith(idParam, request.params);
    const body = parseWith(
      z.object({ reason: z.string().trim().min(1, 'Eine Begründung ist Pflicht').max(500) }),
      request.body,
    );
    return revertCharacter(id, body.reason, contextOf(request));
  });
}