/**
 * GamepadMapper - A comprehensive gamepad mapping and input handling system
 * Addresses shortcomings of the vanilla Gamepad API:
 * - Stick drift compensation with configurable deadzones
 * - Button debouncing to prevent multiple rapid presses
 * - Standardized controller mapping across different brands
 * - Event-driven API instead of polling
 */

export class GamepadMapper {
    constructor(options = {}) {
        // Configuration
        this.config = {
            deadzone: options.deadzone || 0.1,
            debounceTime: options.debounceTime || 50, // ms
            pollRate: options.pollRate || 60, // fps
            enableVibration: options.enableVibration || false,
            ...options
        };

        // State tracking
        this.connectedGamepads = new Map();
        this.previousStates = new Map();
        this.buttonDebounceTimers = new Map();
        this.eventListeners = new Map();
        this.isPolling = false;

        // Standard controller mappings
        this.controllerMappings = this.initializeControllerMappings();

        this.init();
    }

    init() {
        // Set up gamepad connection events
        window.addEventListener('gamepadconnected', this.handleGamepadConnected.bind(this));
        window.addEventListener('gamepaddisconnected', this.handleGamepadDisconnected.bind(this));

        // Check for already connected gamepads
        this.scanForGamepads();

        // Start polling loop
        this.startPolling();
    }

    initializeControllerMappings() {
        return {
            // Standard mapping (most Xbox-compatible controllers)
            'standard': {
                buttons: {
                    0: 'A',      // Bottom face button
                    1: 'B',      // Right face button  
                    2: 'X',      // Left face button
                    3: 'Y',      // Top face button
                    4: 'LB',     // Left bumper
                    5: 'RB',     // Right bumper
                    6: 'LT',     // Left trigger (digital)
                    7: 'RT',     // Right trigger (digital)
                    8: 'SELECT', // Select/Back button
                    9: 'START',  // Start/Menu button
                    10: 'LS',    // Left stick press
                    11: 'RS',    // Right stick press
                    12: 'DPAD_UP',
                    13: 'DPAD_DOWN',
                    14: 'DPAD_LEFT',
                    15: 'DPAD_RIGHT',
                    16: 'HOME'   // Home/Guide button (if available)
                },
                axes: {
                    0: 'LEFT_STICK_X',
                    1: 'LEFT_STICK_Y',
                    2: 'RIGHT_STICK_X',
                    3: 'RIGHT_STICK_Y',
                    // Some controllers have analog triggers on axes 2/3 instead
                    // We'll detect this dynamically
                }
            },

            // PlayStation controllers (DS4, DualSense)
            'playstation': {
                buttons: {
                    0: 'X',      // Cross (bottom)
                    1: 'CIRCLE', // Circle (right)
                    2: 'SQUARE', // Square (left)
                    3: 'TRIANGLE', // Triangle (top)
                    4: 'L1',     // Left bumper
                    5: 'R1',     // Right bumper
                    6: 'L2',     // Left trigger (digital)
                    7: 'R2',     // Right trigger (digital)
                    8: 'SHARE',  // Share button
                    9: 'OPTIONS', // Options button
                    10: 'L3',    // Left stick press
                    11: 'R3',    // Right stick press
                    12: 'DPAD_UP',
                    13: 'DPAD_DOWN',
                    14: 'DPAD_LEFT',
                    15: 'DPAD_RIGHT',
                    16: 'PS'     // PlayStation button
                },
                axes: {
                    0: 'LEFT_STICK_X',
                    1: 'LEFT_STICK_Y',
                    2: 'RIGHT_STICK_X',
                    3: 'RIGHT_STICK_Y'
                }
            },

            // Nintendo Switch Pro Controller
            'nintendo': {
                buttons: {
                    0: 'B',      // B (bottom)
                    1: 'A',      // A (right)
                    2: 'Y',      // Y (left)
                    3: 'X',      // X (top)
                    4: 'L',      // Left bumper
                    5: 'R',      // Right bumper
                    6: 'ZL',     // Left trigger
                    7: 'ZR',     // Right trigger
                    8: 'MINUS',  // Minus button
                    9: 'PLUS',   // Plus button
                    10: 'LS',    // Left stick press
                    11: 'RS',    // Right stick press
                    12: 'HOME',  // Home button
                    13: 'SCREENSHOT' // Screenshot button
                },
                axes: {
                    0: 'DPAD_AXIS',      // Nintendo DPAD on axis 0 (interferes with LEFT_STICK_Y)
                    1: 'LEFT_STICK_X',   // Nintendo left stick X on axis 1
                    2: 'LEFT_STICK_Y',   // Nintendo left stick Y on axis 2 (was showing as RIGHT_STICK_X)
                    3: 'RIGHT_STICK_X',  // Nintendo right stick X on axis 3 (was showing as RIGHT_STICK_Y)
                    4: 'RIGHT_STICK_Y'   // Nintendo right stick Y on axis 4 (Hori controller)
                }
            }
        };
    }

    detectControllerType(gamepad) {
        const id = gamepad.id.toLowerCase();

        // PlayStation controllers
        if (id.includes('playstation') || id.includes('dualshock') || id.includes('dualsense') ||
            id.includes('054c')) { // Sony vendor ID
            return 'playstation';
        }

        // Nintendo controllers
        if (id.includes('nintendo') || id.includes('pro controller') || id.includes('057e')) { // Nintendo vendor ID
            return 'nintendo';
        }

        // Xbox and most other controllers use standard mapping
        return 'standard';
    }

    handleGamepadConnected(event) {
        const gamepad = event.gamepad;
        const controllerType = this.detectControllerType(gamepad);

        console.log(`🎮 Gamepad connected: ${gamepad.id} (Type: ${controllerType})`);

        this.connectedGamepads.set(gamepad.index, {
            gamepad,
            type: controllerType,
            mapping: this.controllerMappings[controllerType],
            lastUpdate: 0
        });

        this.previousStates.set(gamepad.index, {
            buttons: {},
            axes: {}
        });

        this.emit('connected', {
            index: gamepad.index,
            id: gamepad.id,
            type: controllerType
        });
    }

    handleGamepadDisconnected(event) {
        const index = event.gamepad.index;
        console.log(`🎮 Gamepad disconnected: ${event.gamepad.id}`);

        this.connectedGamepads.delete(index);
        this.previousStates.delete(index);

        // Clear any pending debounce timers
        if (this.buttonDebounceTimers.has(index)) {
            const timers = this.buttonDebounceTimers.get(index);
            Object.values(timers).forEach(timer => clearTimeout(timer));
            this.buttonDebounceTimers.delete(index);
        }

        this.emit('disconnected', {
            index: index,
            id: event.gamepad.id
        });
    }

    scanForGamepads() {
        const gamepads = navigator.getGamepads();
        for (let i = 0; i < gamepads.length; i++) {
            if (gamepads[i] && !this.connectedGamepads.has(i)) {
                // Simulate connection event for already connected gamepads
                this.handleGamepadConnected({ gamepad: gamepads[i] });
            }
        }
    }

    startPolling() {
        if (this.isPolling) return;
        this.isPolling = true;

        const poll = () => {
            if (!this.isPolling) return;

            this.updateGamepadStates();
            setTimeout(() => requestAnimationFrame(poll), 1000 / this.config.pollRate);
        };

        requestAnimationFrame(poll);
    }

    stopPolling() {
        this.isPolling = false;
    }

    updateGamepadStates() {
        const gamepads = navigator.getGamepads();

        for (const [index, controllerData] of this.connectedGamepads) {
            const gamepad = gamepads[index];
            if (!gamepad) continue;

            const previousState = this.previousStates.get(index);
            const currentState = {
                buttons: {},
                axes: {}
            };

            // Process buttons
            this.processButtons(gamepad, controllerData, previousState, currentState);

            // Process axes (analog sticks, triggers)
            this.processAxes(gamepad, controllerData, previousState, currentState);

            // Update previous state
            this.previousStates.set(index, currentState);
        }
    }

    processButtons(gamepad, controllerData, previousState, currentState) {
        const mapping = controllerData.mapping.buttons;

        gamepad.buttons.forEach((button, buttonIndex) => {
            const buttonName = mapping[buttonIndex];
            if (!buttonName) return;

            const isPressed = button.pressed;
            const wasPressed = previousState.buttons[buttonName] || false;

            currentState.buttons[buttonName] = isPressed;

            // Handle analog triggers as axes if they have analog values
            if ((buttonName === 'LT' || buttonName === 'RT' || buttonName === 'L2' || buttonName === 'R2') && button.value > 0) {
                const axisName = buttonName === 'LT' || buttonName === 'L2' ? 'LEFT_TRIGGER' : 'RIGHT_TRIGGER';
                const previousValue = previousState.axes[axisName] || 0;

                currentState.axes[axisName] = button.value;

                // Emit axis change for analog triggers
                if (Math.abs(button.value - previousValue) > 0.01) {
                    this.emit('axischange', {
                        gamepadIndex: gamepad.index,
                        axis: axisName,
                        value: button.value,
                        rawValue: button.value
                    });
                }
            }

            // Detect button press (with debouncing)
            if (isPressed && !wasPressed) {
                this.handleButtonPress(gamepad.index, buttonName, button.value);
            }

            // Detect button release
            if (!isPressed && wasPressed) {
                this.handleButtonRelease(gamepad.index, buttonName);
            }
        });
    }

    processAxes(gamepad, controllerData, previousState, currentState) {
        const mapping = controllerData.mapping.axes;

        gamepad.axes.forEach((axisValue, axisIndex) => {
            const axisName = mapping[axisIndex];
            if (!axisName) return;

            // DPAD_AXIS is immune to deadzone filtering and gets special processing
            let processedValue;
            if (axisName === 'DPAD_AXIS') {
                processedValue = this.processDpadAxis(axisValue);
            } else {
                // Apply deadzone to all other axes
                processedValue = this.applyDeadzone(axisValue);
            }

            const previousValue = previousState.axes[axisName] || 0;
            currentState.axes[axisName] = processedValue;

            // Only emit events if value changed significantly
            const threshold = axisName === 'DPAD_AXIS' ? 0.001 : 0.01;
            if (Math.abs(processedValue - previousValue) > threshold) {
                this.emit('axischange', {
                    gamepadIndex: gamepad.index,
                    axis: axisName,
                    value: processedValue,
                    rawValue: axisValue
                });
            }
        });
    }

    processDpadAxis(rawValue) {
        // DPAD axis mapping for Nintendo controllers (raw values to degrees):
        // 1.29 = neutral (not pressed) -> null
        // 0.14 = down -> 270°
        // -0.14 = down right -> 315°
        // -0.43 = right -> 0°
        // -0.71 = up right -> 45°
        // -1 = up -> 90°
        // 1 = up left -> 135°
        // 0.71 = left -> 180°
        // 0.43 = down left -> 225°

        // Use tolerance for floating point comparison
        const tolerance = 0.05;

        // Check for neutral position first
        if (Math.abs(rawValue - 1.29) < tolerance) {
            return null; // Not pressed
        }

        // Map raw values to degrees
        if (Math.abs(rawValue - (-0.43)) < tolerance) {
            return 0; // Right
        } else if (Math.abs(rawValue - (-0.71)) < tolerance) {
            return 45; // Up right
        } else if (Math.abs(rawValue - (-1)) < tolerance) {
            return 90; // Up
        } else if (Math.abs(rawValue - 1) < tolerance) {
            return 135; // Up left
        } else if (Math.abs(rawValue - 0.71) < tolerance) {
            return 180; // Left
        } else if (Math.abs(rawValue - 0.43) < tolerance) {
            return 225; // Down left
        } else if (Math.abs(rawValue - 0.14) < tolerance) {
            return 270; // Down
        } else if (Math.abs(rawValue - (-0.14)) < tolerance) {
            return 315; // Down right
        }

        // Return null for unrecognized values (treat as neutral)
        return null;
    }

    applyDeadzone(value) {
        if (Math.abs(value) < this.config.deadzone) {
            return 0;
        }

        // Scale the remaining range to 0-1
        const sign = Math.sign(value);
        const scaledValue = (Math.abs(value) - this.config.deadzone) / (1 - this.config.deadzone);
        return sign * scaledValue;
    }

    handleButtonPress(gamepadIndex, buttonName, value) {
        // Implement debouncing
        const timerId = `${gamepadIndex}_${buttonName}`;

        if (!this.buttonDebounceTimers.has(gamepadIndex)) {
            this.buttonDebounceTimers.set(gamepadIndex, {});
        }

        const gamepadTimers = this.buttonDebounceTimers.get(gamepadIndex);

        if (gamepadTimers[buttonName]) {
            clearTimeout(gamepadTimers[buttonName]);
        }

        gamepadTimers[buttonName] = setTimeout(() => {
            delete gamepadTimers[buttonName];

            this.emit('buttondown', {
                gamepadIndex,
                button: buttonName,
                value: value || 1
            });
        }, this.config.debounceTime);
    }

    handleButtonRelease(gamepadIndex, buttonName) {
        this.emit('buttonup', {
            gamepadIndex,
            button: buttonName
        });
    }

    // Event system
    on(eventType, callback) {
        if (!this.eventListeners.has(eventType)) {
            this.eventListeners.set(eventType, []);
        }
        this.eventListeners.get(eventType).push(callback);
    }

    off(eventType, callback) {
        if (!this.eventListeners.has(eventType)) return;

        const listeners = this.eventListeners.get(eventType);
        const index = listeners.indexOf(callback);
        if (index > -1) {
            listeners.splice(index, 1);
        }
    }

    emit(eventType, data) {
        if (!this.eventListeners.has(eventType)) return;

        this.eventListeners.get(eventType).forEach(callback => {
            try {
                callback(data);
            } catch (error) {
                console.error(`Error in gamepad event listener for ${eventType}:`, error);
            }
        });
    }

    // Utility methods
    getGamepadInfo(index) {
        return this.connectedGamepads.get(index);
    }

    getConnectedGamepads() {
        return Array.from(this.connectedGamepads.keys());
    }

    setDeadzone(deadzone) {
        this.config.deadzone = Math.max(0, Math.min(1, deadzone));
    }

    setDebounceTime(time) {
        this.config.debounceTime = Math.max(0, time);
    }

    // Vibration support (if available)
    vibrate(gamepadIndex, duration = 200, strongMagnitude = 1.0, weakMagnitude = 1.0) {
        if (!this.config.enableVibration) return false;

        const gamepads = navigator.getGamepads();
        const gamepad = gamepads[gamepadIndex];

        if (!gamepad || !gamepad.vibrationActuator) return false;

        try {
            gamepad.vibrationActuator.playEffect('dual-rumble', {
                duration,
                strongMagnitude: Math.max(0, Math.min(1, strongMagnitude)),
                weakMagnitude: Math.max(0, Math.min(1, weakMagnitude))
            });
            return true;
        } catch (error) {
            console.warn('Vibration not supported:', error);
            return false;
        }
    }

    destroy() {
        this.stopPolling();

        // Clear all timers
        for (const timers of this.buttonDebounceTimers.values()) {
            Object.values(timers).forEach(timer => clearTimeout(timer));
        }

        // Clear all event listeners
        this.eventListeners.clear();

        // Remove window event listeners
        window.removeEventListener('gamepadconnected', this.handleGamepadConnected);
        window.removeEventListener('gamepaddisconnected', this.handleGamepadDisconnected);
    }
}