(function () {
    "use strict";

    var BASE = document.body.dataset.baseUrl || "/";

    let gameState = null;
    let timerInterval = null;
    let selectedCells = [];
    let feedbackTimeout = null;

    function titleCase(word) {
        return word.charAt(0).toUpperCase() + word.slice(1).toLowerCase();
    }

    // DOM refs
    const setupDiv = document.getElementById("game-setup");
    const boardDiv = document.getElementById("game-board");
    const categorySelect = document.getElementById("category-select");
    const boardSizeInput = document.getElementById("board-size");
    const sizeDisplay = document.getElementById("size-display");
    const wordCountInput = document.getElementById("word-count");
    const wordCountDisplay = document.getElementById("word-count-display");
    const newGameBtn = document.getElementById("new-game-btn");
    const gridTable = document.getElementById("grid-table");
    const wordList = document.getElementById("word-list");
    const wordInput = document.getElementById("word-input");
    const guessBtn = document.getElementById("guess-btn");
    const clearSelectionBtn = document.getElementById("clear-selection-btn");
    const guessFeedback = document.getElementById("guess-feedback");
    const timerEl = document.getElementById("timer");
    const completionBanner = document.getElementById("completion-banner");
    const finalTime = document.getElementById("final-time");
    const playAgainBtn = document.getElementById("play-again-btn");
    const inputArea = document.getElementById("input-area");
    const playerNameInput = document.getElementById("player-name");

    // Load categories
    async function loadCategories() {
        try {
            const resp = await fetch(BASE + "api/categories");
            if (!resp.ok) throw new Error("Server error");
            const categories = await resp.json();
            categorySelect.innerHTML = "";
            categories.forEach(function (cat) {
                const opt = document.createElement("option");
                opt.value = cat.id;
                opt.textContent = cat.name.charAt(0).toUpperCase() + cat.name.slice(1);
                categorySelect.appendChild(opt);
            });
        } catch (err) {
            showFeedback("Failed to load categories.", "text-danger");
        }
    }

    boardSizeInput.addEventListener("input", function () {
        sizeDisplay.textContent = this.value;
    });

    wordCountInput.addEventListener("input", function () {
        wordCountDisplay.textContent = this.value;
    });

    // New game
    newGameBtn.addEventListener("click", async function () {
        try {
            const categoryId = parseInt(categorySelect.value);
            const boardSize = parseInt(boardSizeInput.value);
            const wordCount = parseInt(wordCountInput.value);
            const playerName = playerNameInput.value.trim();
            const resp = await fetch(BASE + "api/game/new", {
                method: "POST",
                headers: { "Content-Type": "application/json" },
                body: JSON.stringify({
                    category_id: categoryId,
                    board_size: boardSize,
                    word_count: wordCount,
                    player_name: playerName,
                }),
            });
            if (!resp.ok) {
                const errData = await resp.json().catch(function () { return {}; });
                throw new Error(errData.error || "Failed to create game");
            }
            gameState = await resp.json();
            showBoard();
        } catch (err) {
            showFeedback(err.message || "Failed to create game.", "text-danger");
        }
    });

    function showBoard() {
        setupDiv.classList.add("d-none");
        boardDiv.classList.remove("d-none");
        completionBanner.classList.add("d-none");
        playAgainBtn.classList.add("d-none");
        inputArea.classList.remove("d-none");
        selectedCells = [];
        renderGrid();
        renderWordList();
        startTimer();
    }

    function renderGrid() {
        gridTable.innerHTML = "";
        gameState.grid.forEach(function (row, r) {
            const tr = document.createElement("tr");
            row.forEach(function (letter, c) {
                const td = document.createElement("td");
                td.textContent = letter;
                td.dataset.row = r;
                td.dataset.col = c;
                td.addEventListener("click", function () {
                    onCellClick(r, c, td);
                });
                tr.appendChild(td);
            });
            gridTable.appendChild(tr);
        });
    }

    function renderWordList() {
        wordList.innerHTML = "";
        gameState.words.forEach(function (w) {
            const li = document.createElement("li");
            li.className = "list-group-item";
            li.textContent = titleCase(w.text);
            li.dataset.word = w.text;
            if (w.found) {
                li.classList.add("word-found");
            }
            wordList.appendChild(li);
        });
    }

    // Timer
    function startTimer() {
        if (timerInterval) clearInterval(timerInterval);
        const startedAt = new Date(gameState.started_at);
        function tick() {
            const elapsed = Math.floor((Date.now() - startedAt.getTime()) / 1000);
            const mins = Math.floor(elapsed / 60);
            const secs = elapsed % 60;
            timerEl.textContent = mins + ":" + (secs < 10 ? "0" : "") + secs;
        }
        tick();
        timerInterval = setInterval(tick, 1000);
    }

    function stopTimer() {
        if (timerInterval) {
            clearInterval(timerInterval);
            timerInterval = null;
        }
    }

    // Text guess
    guessBtn.addEventListener("click", submitTextGuess);
    wordInput.addEventListener("keydown", function (e) {
        if (e.key === "Enter") submitTextGuess();
    });

    async function submitTextGuess() {
        const word = wordInput.value.trim();
        if (!word) return;
        wordInput.value = "";
        guessBtn.disabled = true;
        try {
            await sendGuess({ word: word });
        } finally {
            guessBtn.disabled = false;
        }
    }

    // Click selection — two-click: first letter, then last letter
    function onCellClick(row, col, td) {
        if (gameState.status === "completed") return;

        // No start cell yet — this is the first click
        if (selectedCells.length === 0) {
            selectedCells.push({ row: row, col: col });
            td.classList.add("cell-selected");
            updateSelectionButtons();
            return;
        }

        // Clicking the same cell — deselect
        if (selectedCells[0].row === row && selectedCells[0].col === col) {
            clearSelection();
            return;
        }

        // Second click — compute line from start to end
        var startR = selectedCells[0].row;
        var startC = selectedCells[0].col;
        var dr = row - startR;
        var dc = col - startC;

        // Validate straight line
        var absDr = Math.abs(dr);
        var absDc = Math.abs(dc);
        if (absDr !== absDc && absDr !== 0 && absDc !== 0) {
            showFeedback("Selection must form a straight line.", "text-warning");
            clearSelection();
            return;
        }

        var steps = Math.max(absDr, absDc);
        if (steps === 0) return;

        // Unit direction
        var stepR = dr === 0 ? 0 : dr / absDr;
        var stepC = dc === 0 ? 0 : dc / absDc;

        // Build full cell list from start to end
        var cells = [];
        for (var i = 0; i <= steps; i++) {
            cells.push({ row: startR + stepR * i, col: startC + stepC * i });
        }

        // Highlight all cells
        cells.forEach(function (c) {
            var cell = gridTable.querySelector(
                'td[data-row="' + c.row + '"][data-col="' + c.col + '"]'
            );
            if (cell) cell.classList.add("cell-selected");
        });

        // Auto-submit
        selectedCells = cells;
        guessBtn.disabled = true;
        sendGuess({ cells: cells }).then(function () {
            guessBtn.disabled = false;
            clearSelection();
        });
    }

    function updateSelectionButtons() {
        if (selectedCells.length > 0) {
            clearSelectionBtn.classList.remove("d-none");
        } else {
            clearSelectionBtn.classList.add("d-none");
        }
    }

    clearSelectionBtn.addEventListener("click", clearSelection);

    function clearSelection() {
        selectedCells = [];
        document.querySelectorAll(".cell-selected").forEach(function (td) {
            td.classList.remove("cell-selected");
        });
        updateSelectionButtons();
    }

    // Send guess to server
    async function sendGuess(payload) {
        try {
            const resp = await fetch(BASE + "api/game/" + gameState.id + "/guess", {
                method: "POST",
                headers: { "Content-Type": "application/json" },
                body: JSON.stringify(payload),
            });
            if (!resp.ok) throw new Error("Server error");
            const result = await resp.json();
            gameState.words = result.words;
            gameState.status = result.status;

            if (result.correct) {
                highlightFoundCells(result.cells);
                renderWordList();
                showFeedback("Found: " + titleCase(result.word) + "!", "text-success");
            } else {
                showFeedback("Not a match.", "text-danger");
            }

            if (result.status === "completed") {
                gameState.completed_at = result.completed_at;
                gameState.player_name = result.player_name;
                onGameComplete(result.completed_at);
            }
        } catch (err) {
            showFeedback("Request failed. Try again.", "text-danger");
        }
    }

    function highlightFoundCells(cells) {
        cells.forEach(function (c) {
            const td = gridTable.querySelector(
                'td[data-row="' + c.row + '"][data-col="' + c.col + '"]'
            );
            if (td) td.classList.add("cell-found");
        });
    }

    function showFeedback(msg, cls) {
        if (feedbackTimeout) clearTimeout(feedbackTimeout);
        guessFeedback.textContent = msg;
        guessFeedback.className = "mt-2 " + cls;
        feedbackTimeout = setTimeout(function () {
            guessFeedback.textContent = "";
            guessFeedback.className = "mt-2";
            feedbackTimeout = null;
        }, 2000);
    }

    function onGameComplete(completedAt) {
        stopTimer();
        completionBanner.classList.remove("d-none");
        finalTime.textContent = timerEl.textContent;
        playAgainBtn.classList.remove("d-none");
        inputArea.classList.add("d-none");

        var startedAt = new Date(gameState.started_at);
        var endedAt = new Date(completedAt);
        var seconds = Math.floor((endedAt.getTime() - startedAt.getTime()) / 1000);
        saveRecentGame({
            game_id: gameState.id,
            player_name: gameState.player_name || "Anonymous",
            category: gameState.category,
            time_display: timerEl.textContent,
            time_seconds: seconds,
            board_size: gameState.board_size,
            word_count: gameState.words.length,
            completed_at: completedAt,
        });
    }

    function saveRecentGame(entry) {
        var KEY = "ws-recent-games";
        try {
            var games = JSON.parse(localStorage.getItem(KEY) || "[]");
            games.unshift(entry);
            if (games.length > 20) games = games.slice(0, 20);
            localStorage.setItem(KEY, JSON.stringify(games));
        } catch (e) { /* localStorage unavailable */ }
    }

    playAgainBtn.addEventListener("click", function () {
        boardDiv.classList.add("d-none");
        setupDiv.classList.remove("d-none");
    });

    // Init
    loadCategories();
})();