"use strict";
const { randomBytes } = require("node:crypto");

module.exports = function (app) {
  const projectsIssues = {};
  const compulsoryFields = new Set(["issue_title", "issue_text", "created_by"]);
  const optionalFields = new Set(["assigned_to", "status_text"]);
  const updateFields = new Set([
    "issue_title",
    "issue_text",
    "created_by",
    "assigned_to",
    "status_text",
  ]);
  const queryFilters = new Set([
    "_id",
    "issue_title",
    "issue_text",
    "created_by",
    "assigned_to",
    "status_text",
    "open",
  ]);
  const autoGeneratedFields = new Map([
    // FXIME: Not handling potential ID collisions
    ["_id", () => randomBytes(20).toString("hex")],
    ["created_on", () => new Date().toISOString()],
    ["updated_on", () => new Date().toISOString()],
    ["open", () => true],
  ]);

  app
    .route("/api/issues/:project")

    .get(function (req, res) {
      const project = req.params.project;
      const issues = projectsIssues[project];
      const filters = {};
      for (const name of queryFilters) {
        if (req.query[name])
          filters[name] = Array.isArray(req.query[name])
            ? req.query[name][0]
            : req.query[name];
      }
      if (!issues) res.status(404).json({ error: "Project not found" });
      else
        res.json(
          Object.values(issues).filter((issue) =>
            Object.entries(filters).every(([k, v]) => issue[k] === v)
          )
        );
    })

    .post(function (req, res) {
      const project = req.params.project;
      if (!project) {
        res.status(400).json({ error: "Project not specified" });
        return;
      }
      const issue = {};
      for (const name of compulsoryFields) {
        if (!req.body[name]) {
          res.status(400).json({ error: "required field(s) missing" });
          return;
        }
        issue[name] = req.body[name];
      }
      optionalFields.forEach((name) => (issue[name] = req.body[name] ?? ""));
      autoGeneratedFields.forEach(
        (generator, name) => (issue[name] = generator())
      );
      if (!projectsIssues[project])
        projectsIssues[project] = { [issue._id]: { ...issue } };
      else projectsIssues[project][issue._id] = { ...issue };
      res.json(issue);
    })

    .put(function (req, res) {
      const project = req.params.project;
      if (!project) res.status(400).json({ error: "Project not specified" });
      const _id = req.body._id;
      const fields = {};
      updateFields.forEach((name) => {
        if (req.body[name]) fields[name] = req.body[name];
      });
      if (!_id) res.status(400).json({ error: "missing _id" });
      else if (!projectsIssues[project][_id])
        res.status(404).json({ error: "could not update", _id: _id });
      else if (!Object.entries(fields).length)
        res.status(400).json({ error: "no update field(s) sent", _id: _id });
      else {
        Object.entries(fields).forEach(
          ([name, value]) => (projectsIssues[project][_id][name] = value)
        );
        res.json({ result: "successfully updated", _id: _id });
      }
    })

    .delete(function (req, res) {
      const project = req.params.project;
      if (!project) {
        res.status(400).json({ error: "Project not specified" });
        return;
      }
      const _id = req.body._id;
      if (!_id) res.status(400).json({ error: "missing _id" });
      else if (!projectsIssues[project][_id])
        res.status(404).json({ error: "could not delete", _id: _id });
      else {
        delete projectsIssues[project][_id];
        res.json({ result: "successfully deleted", _id: _id });
      }
    });
};