const reviewRoot = "../../target";
const settingsRoot = "../../tools/legal-review";

const express = require("express");
const app = express();
const open = require("open");
const fs = require("fs");
const path = require("path");

// The home page that lists available reports.
app.get("/", function (req, res) {
  let html = "<h1>Report review</h1>";
  const files = fs.readdirSync(reviewRoot);
  const reports = files
    .map((f) => f.match(/^(.*)-report.html$/))
    .filter((m) => m != null)
    .map((m) => m[1]);
  if (reports.length == 0) {
    html +=
      "No reports found. " +
      'Run <pre style="display:inline">enso / gatherLicenses</pre> first.';
  } else {
    html += "Select report:";
    html += "<ul>";
    reports.forEach((report) => {
      html += '<li><a href="/report/' + report + '">' + report + "</a></li>";
    });
    html += "</ul>";
  }
  res.send(html);
});

// Serves the injection script.
app.use("/static", express.static("static"));

// Serves contents of the given report, injecting the review-mode script.
app.get("/report/:report", function (req, res) {
  const report = req.params["report"];
  console.log("Opening report for ", report);
  fs.readFile(
    path.join(reviewRoot, report + "-report.html"),
    "utf-8",
    (err, data) => {
      const injection =
        '<script src="/static/inject.js"></script>' +
        '<script>var reportName = "' +
        report +
        '";</script>';
      if (err) {
        res.status(400).send(err);
      } else {
        const injected = data.replace("</head>", injection + "</head>");
        res.send(injected);
      }
    }
  );
});

// Appends a line to the setting file.
function addLine(report, package, file, line) {
  const dir = path.join(settingsRoot, report, package);
  const location = path.join(dir, file);
  console.log("Adding " + line + " to " + location);
  fs.mkdirSync(dir, {
    recursive: true,
  });
  fs.appendFileSync(location, line + "\n");
}

// Removes a line from the setting file.
function removeLine(report, package, file, line) {
  const location = path.join(settingsRoot, report, package, file);
  console.log("Removing " + line + " from " + location);
  const lines = fs
    .readFileSync(location, "utf-8")
    .split(/\r?\n/)
    .filter((x) => x.length > 0);
  const toRemove = lines.filter((x) => x == line);
  const others = lines.filter((x) => x != line);
  if (toRemove.length == 0) {
    throw (
      "Line " +
      line +
      " was not present in the file. " +
      "Are you sure the report is up to date?"
    );
  } else {
    var newContent = others.join("\n") + "\n";
    if (others.length == 0) {
      newContent = "";
    }
    fs.writeFileSync(location, newContent);
  }
}

// Handles the requests to add or remove lines.
app.use(express.urlencoded({ extended: true }));
app.post("/modify/:report", function (req, res) {
  const report = req.params["report"];
  const package = req.body["package"];
  const action = req.body["action"];
  const file = req.body["file"];
  let line = req.body["line"];
  const encodedLine = req.body["encoded_line"];
  if (encodedLine !== undefined) {
    line = Buffer.from(encodedLine, "base64").toString();
  }

  try {
    if (action == "add") {
      addLine(report, package, file, line);
    } else if (action == "remove") {
      removeLine(report, package, file, line);
    } else {
      throw "Unknown action";
    }
    res.send("OK");
  } catch (error) {
    console.error(error);
    res.status(500).send(error);
  }
});

/*
 * Listens on a random free port, opens a browser with the home page and waits
 * for a newline to terminate.
 */
const server = app.listen(0, () => {
  const port = server.address().port;
  console.log("Listening on at ", "http://localhost:" + port + "/");
  open("http://localhost:" + port + "/");

  console.log("Press ENTER to stop the server.");
  process.stdin.on("data", function (chunk) {
    if (chunk.indexOf("\n") >= 0) {
      console.log("Good bye");
      process.exit(0);
    }
  });
});