import { Hono } from 'hono';
import { zValidator } from '@hono/zod-validator';
import { asc, eq } from 'drizzle-orm';
import { nanoid } from 'nanoid';
import { z } from 'zod';
import { groupInputSchema, type GroupDto } from '@proxy-station/shared';
import { db } from '../db/index.js';
import { groupMembers, policyGroups, rules, nodes } from '../db/schema.js';
import { groupError } from '../services/group-validation.js';

function validate(input: z.output<typeof groupInputSchema>, id?: string): string | null {
  return groupError(input, loadGroups(), db.select({ id: nodes.id, name: nodes.name }).from(nodes).all(), id);
}

function loadGroups(): GroupDto[] {
  const groups = db.select().from(policyGroups).orderBy(asc(policyGroups.sortOrder)).all();
  const members = db.select().from(groupMembers).orderBy(asc(groupMembers.sortOrder)).all();
  return groups.map((g) => ({
    ...g,
    members: members
      .filter((m) => m.groupId === g.id)
      .map((m) => ({ id: m.id, kind: m.memberKind, nodeId: m.nodeId, refName: m.refName, sortOrder: m.sortOrder })),
  }));
}

function replaceMembers(groupId: string, members: z.output<typeof groupInputSchema>['members']) {
  db.delete(groupMembers).where(eq(groupMembers.groupId, groupId)).run();
  members.forEach((m, i) => {
    db.insert(groupMembers)
      .values({
        groupId,
        memberKind: m.kind,
        nodeId: m.kind === 'node' ? (m.nodeId ?? null) : null,
        refName: m.kind === 'node' ? null : (m.refName ?? null),
        sortOrder: i,
      })
      .run();
  });
}

export const groupsRoute = new Hono()
  .get('/', (c) => c.json(loadGroups()))
  .post('/', zValidator('json', groupInputSchema), (c) => {
    const input = c.req.valid('json');
    const error = validate(input);
    if (error) return c.json({ error }, error === '策略组名称已存在' ? 409 : 400);
    const id = nanoid(10);
    try {
      db.transaction(() => {
        db.insert(policyGroups)
          .values({
            id,
            name: input.name,
            type: input.type,
            testUrl: input.testUrl ?? null,
            interval: input.interval ?? null,
            tolerance: input.tolerance ?? null,
            filterRegex: input.filterRegex || null,
            includeAllNodes: input.includeAllNodes,
            sortOrder: input.sortOrder,
            source: 'custom',
          })
          .run();
        replaceMembers(id, input.members);
      });
    } catch (e: any) {
      if (String(e.message).includes('UNIQUE')) return c.json({ error: `策略组「${input.name}」已存在` }, 409);
      throw e;
    }
    return c.json({ id }, 201);
  })
  .put('/reorder', zValidator('json', z.object({ ids: z.array(z.string()) })), (c) => {
    const { ids } = c.req.valid('json');
    ids.forEach((id, i) => db.update(policyGroups).set({ sortOrder: i }).where(eq(policyGroups.id, id)).run());
    return c.json({ ok: true });
  })
  .patch('/:id/enabled', zValidator('json', z.object({ enabled: z.boolean() })), (c) => {
    const res = db
      .update(policyGroups)
      .set({ enabled: c.req.valid('json').enabled })
      .where(eq(policyGroups.id, c.req.param('id')))
      .run();
    if (res.changes === 0) return c.json({ error: '策略组不存在' }, 404);
    return c.json({ ok: true });
  })
  .put('/:id', zValidator('json', groupInputSchema), (c) => {
    const id = c.req.param('id');
    const existing = db.select().from(policyGroups).where(eq(policyGroups.id, id)).get();
    if (!existing) return c.json({ error: '策略组不存在' }, 404);
    const input = c.req.valid('json');
    const error = validate(input, id);
    if (error) return c.json({ error }, error === '策略组名称已存在' ? 409 : 400);
    const oldName = existing.name;
    db.transaction(() => {
      db.update(policyGroups)
        .set({
          name: input.name,
          type: input.type,
          testUrl: input.testUrl ?? null,
          interval: input.interval ?? null,
          tolerance: input.tolerance ?? null,
          filterRegex: input.filterRegex || null,
          includeAllNodes: input.includeAllNodes,
        })
        .where(eq(policyGroups.id, id))
        .run();
      replaceMembers(id, input.members.map((m) => m.kind === 'group' && m.refName === oldName ? { ...m, refName: input.name } : m));
      // 组名变更时同步引用它的成员与规则策略
      if (oldName !== input.name) {
        db.update(groupMembers).set({ refName: input.name }).where(eq(groupMembers.refName, oldName)).run();
        db.update(rules).set({ policy: input.name }).where(eq(rules.policy, oldName)).run();
      }
    });
    return c.json({ ok: true });
  })
  .delete('/:id', (c) => {
    const res = db.delete(policyGroups).where(eq(policyGroups.id, c.req.param('id'))).run();
    if (res.changes === 0) return c.json({ error: '策略组不存在' }, 404);
    return c.json({ ok: true });
  });