// Event handlers — mouse, keyboard, toolbar, waveform controls
import { GATE_W, GATE_H } from './constants.js';
import { state } from './state.js';
import { evaluateAll, findGateAt, findPortAt } from './gates.js';
import { manualStep, clearWaveData } from './waveform.js';
import { startSim, stopSim, adjustSpeed } from './simulation.js';
import { resize, screenToWorld } from './renderer.js';

const PAN_SPEED = 40;

export function initEvents() {
    const canvas = document.getElementById('canvas');

    // ==================== CANVAS MOUSE ====================
    canvas.addEventListener('mousemove', e => {
        state.mouseX = e.offsetX;
        state.mouseY = e.offsetY;

        // Convert to world coords for gate/port detection
        const world = screenToWorld(e.offsetX, e.offsetY);
        state.hoveredPort = findPortAt(world.x, world.y);
        state.hoveredGate = state.hoveredPort ? state.hoveredPort.gate : findGateAt(world.x, world.y);

        if (state.dragging) {
            state.dragging.x = world.x - state.dragOffset.x;
            state.dragging.y = world.y - state.dragOffset.y;
            evaluateAll();
        }

        canvas.style.cursor = state.placingGate ? 'crosshair'
            : state.hoveredPort ? 'pointer'
            : state.hoveredGate ? 'grab'
            : 'default';
    });

    canvas.addEventListener('mousedown', e => {
        if (e.button !== 0) return;
        const world = screenToWorld(e.offsetX, e.offsetY);

        // Placing a new gate
        if (state.placingGate) {
            state.gates.push({
                id: state.nextId++,
                type: state.placingGate,
                x: world.x - GATE_W / 2,
                y: world.y - GATE_H / 2,
                value: 0
            });
            evaluateAll();
            state.placingGate = null;
            return;
        }

        // Port click — connecting
        const port = findPortAt(world.x, world.y);
        if (port) {
            if (state.connecting) {
                if (state.connecting.portType === 'output' && port.type === 'input') {
                    state.connections = state.connections.filter(c => !(c.to === port.gate.id && c.toPort === port.index));
                    state.connections.push({ from: state.connecting.gate.id, fromPort: state.connecting.portIndex, to: port.gate.id, toPort: port.index });
                    evaluateAll();
                } else if (state.connecting.portType === 'input' && port.type === 'output') {
                    state.connections = state.connections.filter(c => !(c.to === state.connecting.gate.id && c.toPort === state.connecting.portIndex));
                    state.connections.push({ from: port.gate.id, fromPort: port.index, to: state.connecting.gate.id, toPort: state.connecting.portIndex });
                    evaluateAll();
                }
                state.connecting = null;
            } else {
                state.connecting = { gate: port.gate, portIndex: port.index, portType: port.type };
            }
            return;
        }

        if (state.connecting) { state.connecting = null; return; }

        // Toggle INPUT/CLOCK
        const gate = findGateAt(world.x, world.y);
        if (gate && (gate.type === 'INPUT' || gate.type === 'CLOCK')) {
            gate.value = gate.value ? 0 : 1;
            evaluateAll();
            return;
        }

        // Drag gate
        if (gate) {
            state.dragging = gate;
            state.dragOffset = { x: world.x - gate.x, y: world.y - gate.y };
            canvas.style.cursor = 'grabbing';
        }
    });

    canvas.addEventListener('mouseup', () => { state.dragging = null; });

    canvas.addEventListener('contextmenu', e => {
        e.preventDefault();
        const world = screenToWorld(e.offsetX, e.offsetY);
        const port = findPortAt(world.x, world.y);
        if (port && port.type === 'input') {
            state.connections = state.connections.filter(c => !(c.to === port.gate.id && c.toPort === port.index));
            evaluateAll();
        } else if (port && port.type === 'output') {
            state.connections = state.connections.filter(c => !(c.from === port.gate.id && c.fromPort === port.index));
            evaluateAll();
        }
    });

    // ==================== MOUSE WHEEL ZOOM ====================
    canvas.addEventListener('wheel', e => {
        e.preventDefault();
        const delta = e.deltaY > 0 ? -0.1 : 0.1;
        const newZoom = Math.max(0.2, Math.min(3, state.zoom + delta));

        // Zoom towards mouse position
        const worldBefore = screenToWorld(e.offsetX, e.offsetY);
        state.zoom = newZoom;
        const worldAfter = screenToWorld(e.offsetX, e.offsetY);

        state.camX += (worldAfter.x - worldBefore.x) * state.zoom;
        state.camY += (worldAfter.y - worldBefore.y) * state.zoom;
    }, { passive: false });

    // ==================== KEYBOARD ====================
    const keysDown = new Set();

    document.addEventListener('keydown', e => {
        keysDown.add(e.key);

        if (e.key === 'Delete' || e.key === 'Backspace') {
            if (state.hoveredGate && document.activeElement === document.body) {
                e.preventDefault();
                const gateId = state.hoveredGate.id;
                state.connections = state.connections.filter(c => c.from !== gateId && c.to !== gateId);
                state.gates = state.gates.filter(g => g.id !== gateId);
                delete state.waveData[gateId];
                state.hoveredGate = null;
                evaluateAll();
            }
        }
        if (e.key === 'Escape') {
            state.placingGate = null;
            state.connecting = null;
        }

        // Pan with arrow keys
        if (e.key === 'ArrowLeft')  { state.camX += PAN_SPEED; e.preventDefault(); }
        if (e.key === 'ArrowRight') { state.camX -= PAN_SPEED; e.preventDefault(); }
        if (e.key === 'ArrowUp')    { state.camY += PAN_SPEED; e.preventDefault(); }
        if (e.key === 'ArrowDown')  { state.camY -= PAN_SPEED; e.preventDefault(); }

        // Zoom with +/- keys
        if ((e.key === '+' || e.key === '=') && document.activeElement === document.body) {
            state.zoom = Math.min(3, state.zoom + 0.1);
            e.preventDefault();
        }
        if ((e.key === '-' || e.key === '_') && document.activeElement === document.body) {
            state.zoom = Math.max(0.2, state.zoom - 0.1);
            e.preventDefault();
        }

        // Reset view with 0
        if (e.key === '0' && document.activeElement === document.body) {
            state.camX = 0;
            state.camY = 0;
            state.zoom = 1;
        }
    });

    document.addEventListener('keyup', e => {
        keysDown.delete(e.key);
    });

    // ==================== TOOLBAR ====================
    document.querySelectorAll('.gate-btn').forEach(btn => {
        btn.addEventListener('click', () => { state.placingGate = btn.dataset.gate; });
    });

    document.getElementById('clear-btn').addEventListener('click', () => {
        if (state.gates.length === 0 || confirm('Clear all gates and connections?')) {
            state.gates = [];
            state.connections = [];
            state.connecting = null;
            state.placingGate = null;
            clearWaveData();
        }
    });

    // Help modal
    document.getElementById('help-btn').addEventListener('click', () => {
        document.getElementById('help-modal').classList.add('visible');
    });
    document.getElementById('help-close').addEventListener('click', () => {
        document.getElementById('help-modal').classList.remove('visible');
    });
    document.getElementById('help-modal').addEventListener('click', e => {
        if (e.target === e.currentTarget) document.getElementById('help-modal').classList.remove('visible');
    });

    // Waveform toggle
    document.getElementById('sim-btn').addEventListener('click', () => {
        state.waveformVisible = !state.waveformVisible;
        document.getElementById('waveform-panel').classList.toggle('visible', state.waveformVisible);
        document.getElementById('sim-btn').classList.toggle('active', state.waveformVisible);
        resize();
    });

    // ==================== WAVEFORM CONTROLS ====================
    document.getElementById('wave-record').addEventListener('click', function() {
        state.recording = !state.recording;
        this.classList.toggle('active', state.recording);
        this.textContent = state.recording ? 'Record' : 'Paused';
    });

    document.getElementById('wave-clear').addEventListener('click', clearWaveData);
    document.getElementById('wave-step').addEventListener('click', manualStep);

    document.getElementById('wave-zoom-in').addEventListener('click', () => {
        state.waveZoom = Math.min(60, state.waveZoom + 5);
    });
    document.getElementById('wave-zoom-out').addEventListener('click', () => {
        state.waveZoom = Math.max(5, state.waveZoom - 5);
    });

    // ==================== SIMULATION CONTROLS ====================
    document.getElementById('sim-run-btn').addEventListener('click', () => {
        if (state.simRunning) stopSim(); else startSim();
    });
    document.getElementById('sim-faster').addEventListener('click', () => adjustSpeed(-100));
    document.getElementById('sim-slower').addEventListener('click', () => adjustSpeed(100));

    // ==================== WAVEFORM PANEL RESIZE ====================
    const resizeHandle = document.getElementById('wave-resize');
    resizeHandle.addEventListener('mousedown', e => {
        state.resizingWave = true;
        e.preventDefault();
    });
    document.addEventListener('mousemove', e => {
        if (state.resizingWave) {
            state.waveformHeight = Math.max(100, Math.min(500, window.innerHeight - e.clientY));
            document.getElementById('waveform-panel').style.height = state.waveformHeight + 'px';
            resize();
        }
    });
    document.addEventListener('mouseup', () => { state.resizingWave = false; });
}