const path = require("path");
const {
  PERMISSION_LEVELS,
  REVIEW_STATES,
  STATUS_VALUES,
  VISIBILITY_VALUES,
  accessForUser,
  createEntry,
  ensureTables,
  getEditableEntry,
  getEntryBySlug,
  grantPermission,
  listEntries,
  listPermissions,
  listUsers,
  listVersions,
  revokePermission,
  searchForAi,
  setEntryWorkflow,
  updateEntry
} = require("./backend/okf_store");
const { renderMarkdown } = require("./backend/markdown");

const PLUGIN_ID = "okf";

module.exports = {
  id: PLUGIN_ID,
  init({ web, db }) {
    ensureTables(db);
    if (!global.lumiFrameworks) {
      global.lumiFrameworks = {};
    }
    global.lumiFrameworks.okf = {
      search: ({ query, user, limit } = {}) => searchForAi(db, query || "", user, limit || 5),
      accessForUser: (user) => accessForUser(db, user)
    };

    const router = web.createRouter();

    router.use((req, res, next) => {
      res.locals.okfAccess = accessForUser(db, req.session.user);
      next();
    });

    router.get("/", requireLogin, (req, res) => {
      const filters = {
        q: req.query.q || "",
        category: req.query.category || "",
        tag: req.query.tag || ""
      };
      const entries = listEntries(db, filters, req.session.user);
      res.render(view("index"), {
        title: "Knowledge",
        entries,
        filters,
        categories: categoriesFor(entries),
        tags: tagsFor(entries)
      });
    });

    router.get("/admin", requireOkfManagement(db), (req, res) => {
      renderAdmin(req, res, db);
    });

    router.post("/admin/entries", requireOkfEdit(db), (req, res) => {
      try {
        const entry = createEntry(db, req.body, req.session.user);
        req.session.flash = { type: "success", message: "OKF entry created." };
        res.redirect(`/plugins/${PLUGIN_ID}/admin?edit=${encodeURIComponent(entry.slug)}`);
      } catch (error) {
        req.session.flash = { type: "error", message: error.message };
        res.redirect(`/plugins/${PLUGIN_ID}/admin`);
      }
    });

    router.post("/admin/entries/:slug", requireOkfEdit(db), (req, res) => {
      try {
        const entry = updateEntry(db, req.params.slug, req.body, req.session.user);
        req.session.flash = { type: "success", message: "OKF entry updated." };
        res.redirect(`/plugins/${PLUGIN_ID}/admin?edit=${encodeURIComponent(entry.slug)}`);
      } catch (error) {
        req.session.flash = { type: "error", message: error.message };
        res.redirect(`/plugins/${PLUGIN_ID}/admin?edit=${encodeURIComponent(req.params.slug)}`);
      }
    });

    router.post("/admin/entries/:slug/:action", requireOkfManagement(db), (req, res) => {
      try {
        const entry = setEntryWorkflow(db, req.params.slug, req.params.action, req.session.user, req.body.note || "");
        req.session.flash = { type: "success", message: "OKF workflow updated." };
        res.redirect(`/plugins/${PLUGIN_ID}/admin?edit=${encodeURIComponent(entry.slug)}`);
      } catch (error) {
        req.session.flash = { type: "error", message: error.message };
        res.redirect(`/plugins/${PLUGIN_ID}/admin?edit=${encodeURIComponent(req.params.slug)}`);
      }
    });

    router.post("/admin/permissions", requireAdmin, (req, res) => {
      try {
        grantPermission(db, req.body, req.session.user);
        req.session.flash = { type: "success", message: "OKF permission granted." };
      } catch (error) {
        req.session.flash = { type: "error", message: error.message };
      }
      res.redirect(`/plugins/${PLUGIN_ID}/admin#okf-permissions`);
    });

    router.post("/admin/permissions/:id/revoke", requireAdmin, (req, res) => {
      try {
        revokePermission(db, req.params.id, req.session.user);
        req.session.flash = { type: "success", message: "OKF permission revoked." };
      } catch (error) {
        req.session.flash = { type: "error", message: error.message };
      }
      res.redirect(`/plugins/${PLUGIN_ID}/admin#okf-permissions`);
    });

    router.get("/:slug", requireLogin, (req, res) => {
      const entry = getEntryBySlug(db, req.params.slug, req.session.user);
      if (!entry) {
        return res.status(404).render("error", {
          title: "Knowledge entry unavailable",
          message: "That OKF entry was not found or is not visible to your account."
        });
      }
      res.render(view("entry"), {
        title: entry.title,
        entry,
        renderMarkdown
      });
    });

    web.mount(`/plugins/${PLUGIN_ID}`, router, {
      label: "Knowledge",
      role: "public",
      authRequired: true,
      section: "community",
      canAccess: (user) => Boolean(user)
    });
    web.addNavItem({
      label: "OKF Management",
      path: `/plugins/${PLUGIN_ID}/admin`,
      role: "public",
      authRequired: true,
      section: "admin",
      canAccess: (user) => accessForUser(db, user).canEdit
    });
  }
};

function renderAdmin(req, res, db) {
  const filters = {
    q: req.query.q || "",
    status: req.query.status || "",
    category: req.query.category || "",
    tag: req.query.tag || ""
  };
  const entries = listEntries(db, filters, req.session.user, { management: true });
  const selected = req.query.edit ? getEditableEntry(db, req.query.edit) : null;
  const versions = selected ? listVersions(db, selected.id) : [];
  res.render(view("admin"), {
    title: "OKF Management",
    entries,
    filters,
    selected,
    versions,
    permissions: listPermissions(db),
    users: listUsers(db),
    levels: PERMISSION_LEVELS,
    statuses: STATUS_VALUES,
    visibilityValues: VISIBILITY_VALUES,
    reviewStates: REVIEW_STATES,
    categories: categoriesFor(entries),
    tags: tagsFor(entries),
    renderMarkdown
  });
}

function view(name) {
  return path.join(__dirname, "views", `${name}.ejs`);
}

function requireLogin(req, res, next) {
  if (req.session.user) return next();
  return res.redirect("/login");
}

function requireAdmin(req, res, next) {
  if (req.session.user?.isAdmin) return next();
  return denied(res);
}

function requireOkfManagement(db) {
  return (req, res, next) => {
    if (accessForUser(db, req.session.user).canEdit) return next();
    return denied(res);
  };
}

function requireOkfEdit(db) {
  return (req, res, next) => {
    if (accessForUser(db, req.session.user).canEdit) return next();
    return denied(res);
  };
}

function denied(res) {
  return res.status(403).render("error", {
    title: "Access denied",
    message: "You do not have access to that page."
  });
}

function categoriesFor(entries) {
  return Array.from(new Set(entries.map((entry) => entry.category).filter(Boolean))).sort();
}

function tagsFor(entries) {
  return Array.from(new Set(entries.flatMap((entry) => entry.tags || []).filter(Boolean))).sort();
}