// plumbing.js — read-only JSON utility API.
//
// This is plumbing, not part of the product surface. The workshop UI renders
// HTML; anything that wants structured data (the bliss CLI, scripts, tooling)
// reads it here instead of scraping fragments. Read-only by design: all writes
// still go through the real /workshop/* endpoints a human uses, so this stays a
// thin mirror of model.* with no business logic of its own.

const express = require("express");
const model = require("./db");

const router = express.Router();

// Private structures are invisible through the plumbing too. Every structure-
// scoped route carries :id, so one param guard covers them all; a caller who
// isn't on the member list gets a 404, same as the workshop.
router.param("id", (req, res, next, id) => {
  if (!model.canAccessStructure(req.session && req.session.userId, id)) {
    return res.status(404).json({ error: "not found" });
  }
  next();
});

// Wrap a handler so thrown errors come back as JSON instead of an HTML stack.
function json(handler) {
  return (req, res) => {
    try {
      const body = handler(req);
      if (body === undefined || body === null) {
        return res.status(404).json({ error: "not found" });
      }
      return res.json(body);
    } catch (e) {
      return res.status(500).json({ error: String(e), stack: e.stack });
    }
  };
}

// All structures the caller is allowed to see (private ones they aren't a
// member of are omitted).
router.get(
  "/structures",
  json((req) =>
    model
      .getStructures()
      .filter((s) =>
        model.canAccessStructure(req.session && req.session.userId, s.id),
      ),
  ),
);

// One structure with everything the sidebar shows, in one call.
router.get(
  "/structures/:id",
  json((req) => {
    const structure = model.getStructure(req.params.id);
    if (!structure) return null;
    return {
      structure,
      routes: model.getRoutes(req.params.id),
      templates: model.getTemplates(req.params.id),
      dbs: model.getDbsForStructure(req.params.id),
      files: model.getFilesForStruct(req.params.id),
    };
  }),
);

// One route, including its handler source.
router.get(
  "/structures/:id/routes/:routeId",
  json((req) => model.getRoute(req.params.routeId)),
);

// One template, including content + test_object.
router.get(
  "/structures/:id/templates/:templateId",
  json((req) => model.getTemplate(req.params.templateId)),
);

// One db (scoped to the structure), including its library source.
router.get(
  "/structures/:id/dbs/:dbId",
  json((req) => model.getDbForStructure(req.params.id, req.params.dbId)),
);

// Files attached to a structure.
router.get(
  "/structures/:id/files",
  json((req) => model.getFilesForStruct(req.params.id)),
);

// Version history (newest first) for a route handler, template, or db library.
// Each row is a summary; fetch /versions/:versionId for the full snapshot.
router.get(
  "/structures/:id/routes/:routeId/versions",
  json((req) => model.getVersions("route", req.params.routeId)),
);
router.get(
  "/structures/:id/templates/:templateId/versions",
  json((req) => model.getVersions("template", req.params.templateId)),
);
router.get(
  "/structures/:id/dbs/:dbId/versions",
  json((req) => model.getVersions("db", req.params.dbId)),
);

// One version, including its full snapshot (the versioned fields). Not scoped
// by :id, so it carries its own access check against the version's structure.
router.get(
  "/versions/:versionId",
  json((req) => {
    const version = model.getVersion(req.params.versionId);
    if (!version) return null;
    if (
      !model.canAccessStructure(
        req.session && req.session.userId,
        version.structure_id,
      )
    ) {
      return null;
    }
    return version;
  }),
);

// Logs for a route. ?since=<id> returns only newer rows (for polling).
router.get(
  "/structures/:id/routes/:routeId/logs",
  json((req) => {
    const { since } = req.query;
    const logs =
      since !== undefined
        ? model.getNewLogsByRoute(req.params.routeId, since)
        : model.getLogsByRoute(req.params.routeId);
    return { logs, since: model.getMostRecentLogIdByRoute(req.params.routeId) };
  }),
);

module.exports = router;