const express = require("express");
const fs = require("fs");
const path = require("path");
const morgan = require("morgan");
const bodyParser = require("body-parser");
const sqlite3 = require("sqlite3").verbose();
const app = express();
const port = 3000;

// Create an SQLite database and initialize tables
const db = new sqlite3.Database("db/results.db", (err) => {
  if (err) {
    console.error("Error opening SQLite database:", err.message);
  } else {
    console.log("Connected to SQLite database");
    db.run(`
            CREATE TABLE IF NOT EXISTS button_clicks (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                session_id TEXT,
                animal_name TEXT,
                button_name TEXT,
                timestamp DATETIME DEFAULT CURRENT_TIMESTAMP NOT NULL,
                time_difference INTEGER  -- Add this column for time difference
            )
        `);
    db.run(`
            CREATE TABLE IF NOT EXISTS animals (
              id INTEGER PRIMARY KEY AUTOINCREMENT,
              name TEXT NOT NULL UNIQUE,
              timestamp DATETIME DEFAULT CURRENT_TIMESTAMP NOT NULL
              )
        `);
  }
});

var accessLogStream = fs.createWriteStream(
  path.join(__dirname, "log", "access.log"),
  { flags: "a" },
);

app.use(bodyParser.json());
app.use(morgan("combined", { stream: accessLogStream }));

var animals;
// check and load animals into redis
try {
  fs.readFile("./animals.json", function (err, data) {
    if (err) {
      throw err;
    }
    var jsondata = JSON.parse(data);
    animals = jsondata.animals;
    for (const animal of animals) {
      db.run(
        `
      INSERT INTO animals(name)
      SELECT '${animal}'
      WHERE NOT EXISTS(SELECT 1 FROM animals WHERE name = '${animal}');
      `,
        (err) => {
          if (err) {
            console.error(`Error inserting animal ${animal}: `, err.message);
          } else {
            console.log(`Success inserting animal ${animal}`);
          }
        },
      );
    }
  });
} catch (error) {
  console.error("Error loading animals:", error);
  animals = ["Dog", "Cat", "Elephant", "Lion", "Giraffe"];
}

// Serve the HTML file
app.get("/", (req, res) => {
  res.sendFile(__dirname + "/index.html");
});
app.get("/asset/frontend.js", (req, res) => {
  res.sendFile(__dirname + "/asset/frontend.js");
});

// Route to get a random animal name
app.get("/getNextAnimal", async (req, res) => {
  try {
    // TODO this is currently random, and should have a bit of reasoning behind the next choice
    const randomIndex = Math.floor(Math.random() * animals.length);
    const randomAnimal = animals[randomIndex];
    res.json({ animalName: randomAnimal });
  } catch (error) {
    console.error("Error fetching random animal:", error);
    res.status(500).json({ error: "Internal server error" });
  }
});

// Route to record button clicks along with session IDs in SQLite
app.post("/recordButtonClick", (req, res) => {
  try {
    //const { buttonName, sessionId } = req.body;
    const result = req.body;
    console.error(result);

    db.run(
      "INSERT INTO button_clicks (session_id, animal_name, button_name, timestamp, time_difference) VALUES (?, ?, ?, ?, ?)",
      [
        result.session,
        result.animal,
        result.button,
        result.time,
        result.difference,
      ],
      (err) => {
        if (err) {
          console.error("Error recording button click:", err.message);
          res.status(500).json({ error: "Internal server error" });
        } else {
          res.sendStatus(200);
        }
      },
    );
  } catch (error) {
    console.error("Error recording button click:", error);
    res.status(500).json({ error: "Internal server error" });
  }
});

// Route to show the current results from SQLite
app.get("/results", async (req, res) => {
  try {
    const results = {
      count: {},
      avgTimes: {},
    };
    const getCount = new Promise((resolve, reject) => {
      db.all(
        `
          SELECT animal_name, button_name, COUNT(*) AS count
          FROM button_clicks
          GROUP BY button_name, animal_name
        `,
        (err, rows) => {
          if (err) {
            reject("getCount: " + err.message);
          } else {
            rows.forEach((row) => {
              if (typeof results.count[row.animal_name] == "undefined") {
                results.count[row.animal_name] = {};
              }
              results.count[row.animal_name][row.button_name] = row.count;
            });
            resolve();
          }
        },
      );
    });
    const getAvgTime = new Promise((resolve, reject) => {
      db.all(
        `
            SELECT animal_name, button_name, AVG(time_difference) AS time
            FROM button_clicks
            GROUP BY animal_name, button_name;
        `,
        (err, rows) => {
          if (err) {
            reject("getAvgTime: " + err.message);
          } else {
            rows.forEach((row) => {
              if (typeof results.avgTimes[row.animal_name] == "undefined") {
                results.avgTimes[row.animal_name] = {};
              }
              results.avgTimes[row.animal_name][row.button_name] = row.time;
            });
            resolve();
          }
        },
      );
    });
    const getTotalAvgTime = new Promise((resolve, reject) => {
      db.all(
        `
            SELECT animal_name, AVG(time_difference) AS time
            FROM button_clicks
            GROUP BY animal_name;
        `,
        (err, rows) => {
          if (err) {
            reject("getTotalAvgTime: " + err.message);
          } else {
            rows.forEach((row) => {
              if (typeof results.avgTimes[row.animal_name] == "undefined") {
                results.avgTimes[row.animal_name] = {};
              }
              results.avgTimes[row.animal_name]["total"] = row.time;
            });
            resolve();
          }
        },
      );
    });
    await Promise.all([getCount, getTotalAvgTime, getAvgTime]);
    res.json(results);
  } catch (error) {
    console.error("Error fetching results:", error);
    res.status(500).json({ error: "Internal server error" });
  }
});

app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});