import QtQuick 2.2
import "pages"

Item {
    id: functions

    function get_piece(i) {
        if (i === 0 || i === 7) return "r";
        else if (i === 1 || i === 6) return "n";
        else if (i === 2 || i === 5) return "b";
        else if (i === 3) return "q";
        else if (i === 4) return "k";
        else if (i >= 8 && i <= 15) return "p";
    }

    function fill() {
        for (var i = 0; i < 16; i++) {
            const piece = get_piece(i);

            board.itemAt(i).piece = "b" + piece;
            board.itemAt(-i + 63).piece = "w" + piece;
        }
        // Swap white king & queen
        board.itemAt(60).piece = [board.itemAt(59).piece, board.itemAt(59).piece = board.itemAt(60).piece][0];
    }

    function clear() {
        for (var i = 0; i < 64; i++) {
            board.itemAt(i).piece = "";
        }
    }

    property var selected: []
    function select(i) {
        if (selected.length < 2 && game_id !== "" && turn) {
            if (selected.indexOf(i) === -1) selected.push(i)
            else selected.splice(selected.indexOf(i), 1)

            if (selected.length === 2) {
                board.itemAt(selected[0]).border.width = 0;
                move(selected[0], selected[1]);
            } else {
                board.itemAt(i).border.width ^= parseInt(0.1 * board.itemAt(i).width);
            }
        }
    }

    function convert_index(i) {
        const first = (i % 8) + 'a'.charCodeAt(0);
        const second = (7 - parseInt(i / 8)) + '1'.charCodeAt(0);
        return String.fromCharCode(first, second);
    }

    function convert_movement(movement) {
        const a = movement[0].charCodeAt(0) - 'a'.charCodeAt(0);
        const b = 8 - parseInt(movement[1])
        const c = movement[2].charCodeAt(0) - 'a'.charCodeAt(0);
        const d = 8 - parseInt(movement[3])
        return [b * 8 + a, d * 8 + c];
    }

    function move_piece(from, to) {
        if (board.itemAt(from).piece !== "") {
            board.itemAt(to).piece = board.itemAt(from).piece;
            board.itemAt(from).piece = "";
        }
    }

    function move(from, to) {
        post("board/game/" + game_id + "/move/" + convert_index(from) + convert_index(to), "", function (response) {
            console.log(JSON.stringify(response));
            if (response["ok"]) {
                turn = false;
                // move_piece(from, to);
            }
        })
        selected = [];
    }

    function castle(move) {
        console.log("'" + move + "'");
        if (["e1c1", "e1g1", "e8c8", "e8g8"].indexOf(move) !== -1) {
            var rook;
            switch (move) {
            case "e1c1":
                rook = convert_movement("a1d1")
                break;
            case "e1g1":
                rook = convert_movement("h1f1")
                break;
            case "e8c8":
                rook = convert_movement("a8d8")
                break;
            case "e8g8":
                rook = convert_movement("h8f8")
                break;
            }
            console.log(rook);

            move_piece(rook[0], rook[1]);
        }
    }

    // END LOGIC

    property bool start: true
    property bool turn: true
    property var game_id: ""
    property var moves: ""

    function event_stream() {
        var xhr = new XMLHttpRequest();
        xhr.open("GET", "https://lichess.org/api/stream/event");
        xhr.seenBytes = 0;
        xhr.setRequestHeader("Authorization", "Bearer " + access_token.value);

        xhr.onreadystatechange = function() {
            if (xhr.readyState === 3) {
                const new_data = xhr.response.substr(xhr.seenBytes);
                xhr.seenBytes = xhr.responseText.length;

                if (new_data !== "\n") {
                    // TODO: Fix resign
                    console.log("[" + new_data.replace(/(?:\r\n|\r|\n)/g, ",").replace(/\,$/, "") + "]");

                    const data_arr = JSON.parse("[" + new_data.replace(/(?:\r\n|\r|\n)/g, ",").replace(/\,$/, "") + "]");
                    data_arr.forEach(function (data) {
                        if (data["type"] === "gameStart") {
                            information.text = qsTr("Game started!");
                            clear();
                            stop_game();
                            fill();
                            game_id = data["game"]["id"];
                            game_stream();
                        } else if (data["type"] === "challenge") {
                            var dialog = pageStack.push("pages/ChallengeDialog.qml", {"name": data["challenge"]["challenger"]["name"]});
                            dialog.accepted.connect(function() {
                                post("challenge/" + data["challenge"]["id"] + "/accept", "", function() {});
                            })
                            dialog.rejected.connect(function() {
                                post("challenge/" + data["challenge"]["id"] + "/decline", "", function() {});
                            })
                        }
                    });
                }
            }
        };

        xhr.send();
    }

    property var game_xhr;
    function game_stream() {
        game_xhr = new XMLHttpRequest();
        game_xhr.open("GET", "https://lichess.org/api/board/game/stream/" + game_id);
        game_xhr.seenBytes = 0;
        game_xhr.setRequestHeader("Authorization", "Bearer " + access_token.value);

        game_xhr.onreadystatechange = function() {
            if (game_xhr.readyState === 3) {
                const new_data = game_xhr.response.substr(game_xhr.seenBytes);
                game_xhr.seenBytes = game_xhr.responseText.length;

                if (new_data !== "\n") {
                    console.log("[" + new_data.replace(/(?:\r\n|\r|\n)/g, ",").replace(/\,$/, "") + "]");

                    const data_arr = JSON.parse("[" + new_data.replace(/(?:\r\n|\r|\n)/g, ",").replace(/\,$/, "") + "]");
                    data_arr.forEach(function (data) {
                        var all_moves, status;
                        if (data["type"] === "gameFull") {
                            all_moves = data["state"]["moves"];
                            status = data["state"]["status"];
                        } else if (data["type"] === "gameState") {
                            all_moves = data["moves"];
                            status = data["status"];
                        } else if (data["error"]) {
                            information.text = qsTr("An error occurred: ") + data["error"];
                            clear();
                            stop_game();
                            return;
                        } else if (data["type"] === "chatLine") {
                            chat.text = data["username"] + ": " + data["text"];
                            return;
                        }

                        const new_moves = all_moves.slice(moves.length)
                        moves += new_moves;

                        turn = (moves.split(" ").length === 1 && start) || moves.split(" ").length % 2 === (start ? 0 : 1);

                        new_moves.split(" ").forEach(function(move) {
                            if (move !== "") {
                                // TODO: Implement pawn promotion and en passant
                                const arr = convert_movement(move);
                                move_piece(arr[0], arr[1]);
                                castle(move);
                            }
                        });

                        if (status !== "started") {
                            stop_game();
                            information.text = qsTr("Game over: ") + status;
                        }
                    });
                }
            }
        };

        game_xhr.send();
    }

    function post(path, params, callback) {
        var xhr = new XMLHttpRequest();
        xhr.open("POST", "https://lichess.org/api/" + path);
        xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        xhr.setRequestHeader("Authorization", "Bearer " + access_token.value);

        xhr.onreadystatechange = function() {
            if (xhr.readyState === 4)
                callback(JSON.parse(xhr.responseText));
        }
        xhr.send(params);
    }

    function stop_game() {
        try {
            game_id = "";
            moves = "";
            game_xhr.abort();
        } catch (Exception) {} // idc
    }

    function abort() {
        post("board/game/" + game_id + "/abort", "", function (response) {
            if (response["ok"]) {
                information.text = qsTr("Please start a game");
                clear();
                stop_game();
            }
        })
    }

    function resign() {
        post("board/game/" + game_id + "/resign", "", function (response) {
            if (response["ok"]) {
                information.text = qsTr("Game over: ") + qsTr("Resigned");
                stop_game();
            }
        })
    }

    function offer_draw() {
        post("board/game/" + game_id + "/draw/yes", "", function (response) {
            if (response["ok"])
                information.text = qsTr("Offered draw");
        })
    }

    function challenge(username) {
        post("challenge/" + username, "rated=false&clock.limit=10800&clock.increment=60&days=14&color=white", function (response) {
            if (!response["error"]) {
                information.text = qsTr("Waiting for ") + response["challenge"]["destUser"]["name"];
                console.log(JSON.stringify(response));
            }
        });
    }

    function start_seek() {
        var xhr = new XMLHttpRequest();
        xhr.open("GET", "https://lichess.org/api/account");
        xhr.setRequestHeader("Authorization", "Bearer " + access_token.value);

        xhr.onreadystatechange = function() {
            if (xhr.readyState === 3) {
                console.log(xhr.responseText);
            }
        };

        xhr.send();
    }
}