import { Router } from 'express';
import { z } from 'zod';
import * as repo from '../../db/repos/resources.js';
import * as sourceDocs from '../../db/repos/source_docs.js';
import * as audit from '../../db/repos/audit.js';
import { validate } from '../validate.js';
import { NotFoundError, ValidationError, ConflictError, asyncWrap } from '../errors.js';
import { requireWrite, requireOwner, divertToPending } from '../cap.js';

const RUNTIME = ['lxc', 'vm', 'docker', 'bare-metal'];
const STATUSES = ['running', 'stopped', 'down', 'unknown'];

const baseFields = {
  slug: z.string().min(1).max(64).regex(/^[a-z0-9-]+$/),
  name: z.string().min(1).max(200),
  runtime_type: z.enum(RUNTIME),
  host: z.string().nullable().optional(),
  url: z.string().nullable().optional(),
  version: z.string().nullable().optional(),
  status: z.enum(STATUSES).optional(),
  monitoring: z.record(z.string(), z.any()).nullable().optional(),
  metadata: z.record(z.string(), z.any()).nullable().optional(),
  last_check: z.string().datetime().nullable().optional(),
  maintenance_until: z.string().datetime().nullable().optional()
};

const createSchema = z.object(baseFields);
const patchSchema = z.object(Object.fromEntries(
  Object.entries(baseFields).map(([k, v]) => [k, v.optional()])
));

const idParams = z.object({ id: z.string().uuid() });
const spaceParams = z.object({ space_id: z.string().uuid() });
const depParams = z.object({ id: z.string().uuid(), dep_id: z.string().uuid() });
const depBody = z.object({
  depends_on: z.string().uuid(),
  kind: z.string().nullable().optional()
});

export const router = Router();
export const spacesScopedRouter = Router({ mergeParams: true });

spacesScopedRouter.get('/',
  validate({ params: spaceParams }),
  asyncWrap(async (req, res) => { res.json(await repo.listBySpace(req.params.space_id)); })
);

spacesScopedRouter.post('/',
  requireWrite('resource'),
  validate({ params: spaceParams, body: createSchema }),
  asyncWrap(async (req, res) => {
    const payload = { ...req.body, space_id: req.params.space_id };
    if (req.capTier === 'suggest') {
      return divertToPending(req, res, { entity_type: 'resource', action: 'create', payload });
    }
    try {
      const row = await repo.create(payload, req.actor);
      res.status(201).json(row);
    } catch (e) {
      if (e.code === '23503') throw new ValidationError('invalid space', { space_id: req.params.space_id });
      throw e;
    }
  })
);

router.get('/:id',
  validate({ params: idParams }),
  asyncWrap(async (req, res) => {
    const row = await repo.getById(req.params.id);
    if (!row) throw new NotFoundError('resource not found');
    res.json(row);
  })
);

router.patch('/:id',
  requireWrite('resource'),
  validate({ params: idParams, body: patchSchema }),
  asyncWrap(async (req, res) => {
    const existing = await repo.getById(req.params.id);
    if (!existing) throw new NotFoundError('resource not found');
    if (req.capTier === 'suggest') {
      return divertToPending(req, res, {
        entity_type: 'resource', entity_id: req.params.id, action: 'update', payload: req.body
      });
    }
    res.json(await repo.update(req.params.id, req.body, req.actor));
  })
);

router.delete('/:id',
  requireWrite('resource'),
  validate({ params: idParams }),
  asyncWrap(async (req, res) => {
    const existing = await repo.getById(req.params.id);
    if (!existing) throw new NotFoundError('resource not found');
    if (req.capTier === 'suggest') {
      return divertToPending(req, res, {
        entity_type: 'resource', entity_id: req.params.id, action: 'delete', payload: {}
      });
    }
    await repo.del(req.params.id, req.actor);
    res.status(204).end();
  })
);

// Dependency wiring is infra-level: owner-only, never diverted to pending_changes.
router.post('/:id/dependencies',
  requireOwner,
  validate({ params: idParams, body: depBody }),
  asyncWrap(async (req, res) => {
    if (req.params.id === req.body.depends_on) {
      throw new ValidationError('resource cannot depend on itself');
    }
    try {
      await repo.addDependency(req.params.id, req.body.depends_on, req.body.kind);
      res.status(201).json({ resource_id: req.params.id, depends_on: req.body.depends_on });
    } catch (e) {
      if (e.code === '23503') throw new ConflictError('cross-space or unknown resource', {
        resource_id: req.params.id, depends_on: req.body.depends_on, hint: 'dependencies must share a space_id'
      });
      throw e;
    }
  })
);

router.get('/:id/dependencies',
  validate({ params: idParams }),
  asyncWrap(async (req, res) => {
    res.json(await repo.listDependencies(req.params.id));
  })
);

router.delete('/:id/dependencies/:dep_id',
  requireOwner,
  validate({ params: depParams }),
  asyncWrap(async (req, res) => {
    await repo.removeDependency(req.params.id, req.params.dep_id);
    res.status(204).end();
  })
);

router.get('/:id/source-docs',
  validate({ params: idParams }),
  asyncWrap(async (req, res) => {
    res.json(await sourceDocs.listByResource(req.params.id));
  })
);

router.get('/:id/changes',
  validate({ params: idParams }),
  asyncWrap(async (req, res) => {
    res.json(await audit.listForEntity('resource', req.params.id));
  })
);