import { config, saveSettings, defaultConfig, setConfig } from './config.js';
import { cols, rows, selectedType, setSelectedType, clearGrid, canvas, cellSize, brushSize, setBrushSize } from './state.js';
import { spawnCell } from './physics.js';
import { stepOnce } from './index.js';

export const elementCategories = [
    {
        title: 'Solids',
        items: [
            { type: 'sand', color: '#e8b656', label: 'Sand' },
            { type: 'dirt', color: '#8b5a2b', label: 'Dirt' },
            { type: 'rock', color: '#7a7e85', label: 'Rock' },
            { type: 'wood', color: '#704020', label: 'Wood' },
            { type: 'ice', color: '#bce8f5', label: 'Ice', textColor: '#000' }
        ]
    },
    {
        title: 'Liquids',
        items: [
            { type: 'water', color: '#2582eb', label: 'Water' },
            { type: 'lava', color: '#ff5a00', label: 'Lava' },
            { type: 'oil', color: '#382f23', label: 'Oil' },
            { type: 'acid', color: '#68f518', label: 'Acid', textColor: '#000' }
        ]
    },
    {
        title: 'Organics & Gas',
        items: [
            { type: 'plant', color: '#228B22', label: 'Plant' },
            { type: 'grass', color: '#38b000', label: 'Grass' },
            { type: 'fire', color: '#ff6600', label: 'Fire' },
            { type: 'steam', color: '#dcf3f9', label: 'Steam', textColor: '#000' },
            { type: 'smoke', color: '#4a4e54', label: 'Smoke' }
        ]
    },
    {
        title: 'Explosives & Tools',
        items: [
            { type: 'explosive', color: '#b71c1c', label: 'TNT' },
            { type: 'eraser', color: '#555560', label: 'Eraser', title: 'Or right-click to erase' },
            { type: 'clear', color: '#2a2a30', label: 'Clear All' }
        ]
    }
];

let lastPos = null;

export function setLastPos(pos) {
    lastPos = pos;
}

let brushSizeSlider = null;
let brushSizeValLabel = null;

export function updateBrushUI() {
    if (brushSizeSlider) brushSizeSlider.value = brushSize;
    if (brushSizeValLabel) brushSizeValLabel.textContent = `${brushSize}px`;
}

export function setupUI() {
    // Settings Drawer
    const drawer = document.getElementById('settingsContent');
    const toggle = document.getElementById('toggleDrawer');
    const drawerContainer = document.getElementById('settingsDrawer');
    const pauseBtn = document.getElementById('togglePause');
    const stepBtn = document.getElementById('btnStep');
    
    toggle.addEventListener('click', () => {
        drawerContainer.classList.toggle('open');
    });

    function updatePauseBtn() {
        pauseBtn.textContent = config.time.paused ? '▶' : '⏸';
    }

    pauseBtn.addEventListener('click', () => {
        config.time.paused = !config.time.paused;
        saveSettings();
        updatePauseBtn();
    });
    updatePauseBtn();

    if (stepBtn) {
        stepBtn.addEventListener('click', () => {
            if (config.time.paused) {
                stepOnce();
            } else {
                config.time.paused = true;
                saveSettings();
                updatePauseBtn();
                stepOnce();
            }
        });
    }

    renderSettings(drawer);

    // Elements Drawer
    const elDrawer = document.getElementById('elementContent');
    const elToggle = document.getElementById('toggleElements');
    const elContainer = document.getElementById('elementDrawer');

    elToggle.addEventListener('click', () => {
        elContainer.classList.toggle('closed');
    });

    renderElements(elDrawer);
}

function selectElement(type) {
    setSelectedType(type);
    document.querySelectorAll('.element-btn').forEach(b => {
        if (b.dataset.type === type) {
            b.classList.add('selected');
        } else {
            b.classList.remove('selected');
        }
    });
}

function renderElements(container) {
    container.innerHTML = '';

    // Brush Size Header Control
    const brushBox = document.createElement('div');
    brushBox.className = 'brush-size-box';

    const brushHeader = document.createElement('div');
    brushHeader.className = 'brush-size-header';
    brushHeader.innerHTML = `<span>Brush Size</span>`;
    brushSizeValLabel = document.createElement('span');
    brushSizeValLabel.className = 'brush-val';
    brushSizeValLabel.textContent = `${brushSize}px`;
    brushHeader.appendChild(brushSizeValLabel);

    brushSizeSlider = document.createElement('input');
    brushSizeSlider.type = 'range';
    brushSizeSlider.min = '1';
    brushSizeSlider.max = '25';
    brushSizeSlider.value = brushSize;
    brushSizeSlider.className = 'brush-slider';

    brushSizeSlider.addEventListener('input', (e) => {
        const val = parseInt(e.target.value, 10);
        setBrushSize(val);
        config.brush.size = val;
        saveSettings();
        brushSizeValLabel.textContent = `${val}px`;
    });

    brushBox.appendChild(brushHeader);
    brushBox.appendChild(brushSizeSlider);
    container.appendChild(brushBox);

    // Categorized Buttons (clean without any hotkey numbers)
    elementCategories.forEach(category => {
        const catDiv = document.createElement('div');
        catDiv.className = 'element-category';

        const catTitle = document.createElement('div');
        catTitle.className = 'category-title';
        catTitle.textContent = category.title;
        catDiv.appendChild(catTitle);

        category.items.forEach(btn => {
            const button = document.createElement('button');
            button.className = 'element-btn';
            button.dataset.type = btn.type;
            if (btn.type === selectedType) button.classList.add('selected');
            button.style.backgroundColor = btn.color;
            if (btn.textColor) button.style.color = btn.textColor;

            const labelSpan = document.createElement('span');
            labelSpan.textContent = btn.label;
            button.appendChild(labelSpan);

            button.onclick = () => {
                if (btn.type === 'clear') {
                    if (confirm('Clear the entire canvas?')) {
                        clearGrid();
                    }
                } else {
                    selectElement(btn.type);
                }
            };
            catDiv.appendChild(button);
        });

        container.appendChild(catDiv);
    });
}

export function renderSettings(container) {
    container.innerHTML = '';

    function addControl(group, key, subkey, def) {
        const ctrlDiv = document.createElement('div');

        const labelEl = document.createElement('label');
        let val = subkey ? config[group]?.[key]?.[subkey] : config[group]?.[key];
        labelEl.textContent = def.label;

        const input = document.createElement('input');
        input.type = def.type || 'range';

        if (def.type === 'checkbox') {
            ctrlDiv.className = 'setting-checkbox';
            input.checked = !!val;
            input.addEventListener('change', (e) => {
                if (subkey) config[group][key][subkey] = e.target.checked;
                else config[group][key] = e.target.checked;
                saveSettings();
            });
            ctrlDiv.append(input, labelEl);
        } else if (def.type === 'radio') {
            const fieldset = document.createElement('fieldset');
            const legend = document.createElement('legend');
            legend.textContent = def.label;
            fieldset.appendChild(legend);

            def.options.forEach(option => {
                const radioId = `radio-${group}-${key}-${option}`;
                const radioContainer = document.createElement('div');
                radioContainer.style.display = 'inline-block';
                radioContainer.style.marginRight = '12px';

                const radioInput = document.createElement('input');
                radioInput.type = 'radio';
                radioInput.name = `radio-${group}-${key}`;
                radioInput.value = option;
                radioInput.id = radioId;
                if (val === option) radioInput.checked = true;

                radioInput.addEventListener('change', (e) => {
                    config[group][key] = e.target.value;
                    saveSettings();
                });

                const radioLabel = document.createElement('label');
                radioLabel.textContent = option.charAt(0).toUpperCase() + option.slice(1);
                radioLabel.setAttribute('for', radioId);
                radioLabel.style.marginLeft = '4px';

                radioContainer.append(radioInput, radioLabel);
                fieldset.appendChild(radioContainer);
            });
            return fieldset;
        } else {
            ctrlDiv.className = 'setting-control';
            input.min = def.min;
            input.max = def.max;
            input.step = def.step;
            input.value = val !== undefined ? val : def.min;
            const valueSpan = document.createElement('span');
            valueSpan.className = 'control-val';
            valueSpan.textContent = typeof val === 'number' ? val.toString() : (val || '0');

            input.addEventListener('input', (e) => {
                const newVal = parseFloat(e.target.value);
                if (subkey) config[group][key][subkey] = newVal;
                else config[group][key] = newVal;
                saveSettings();
                valueSpan.textContent = newVal.toFixed(Math.max(def.step.toString().split('.')[1]?.length || 0, 1));
            });
            ctrlDiv.append(labelEl, input, valueSpan);
        }

        return ctrlDiv;
    }

    // Complete settings matching all original groups plus all new elements
    const groups = {
        time: [
            { key: 'speed', label: 'Speed', min: 0, max: 20, step: 1 }
        ],
        global: [
            { key: 'gravity', label: 'Gravity', min: -1.0, max: 2.0, step: 0.1 },
            { key: 'drag', label: 'Drag', min: 0.1, max: 1.0, step: 0.05 }
        ],
        explosive: [
            { key: 'force', label: 'Blast Force', min: 0, max: 20, step: 1 },
            { key: 'radius', label: 'Blast Reach', min: 1, max: 50, step: 1 },
            { key: 'destroy', subkey: 'rock', type: 'checkbox', label: 'Destroy Rock' },
            { key: 'destroy', subkey: 'wood', type: 'checkbox', label: 'Destroy Wood' },
            { key: 'destroy', subkey: 'dirt', type: 'checkbox', label: 'Destroy Dirt' },
            { key: 'destroy', subkey: 'sand', type: 'checkbox', label: 'Destroy Sand' },
            { key: 'destroy', subkey: 'plant', type: 'checkbox', label: 'Destroy Plant' },
            { key: 'destroy', subkey: 'grass', type: 'checkbox', label: 'Destroy Grass' },
            { key: 'destroy', subkey: 'water', type: 'checkbox', label: 'Destroy Water' },
            { key: 'destroy', subkey: 'acid', type: 'checkbox', label: 'Destroy Acid' },
            { key: 'destroy', subkey: 'ice', type: 'checkbox', label: 'Destroy Ice' },
            { key: 'destroy', subkey: 'lava', type: 'checkbox', label: 'Destroy Lava' },
            { key: 'destroy', subkey: 'oil', type: 'checkbox', label: 'Destroy Oil' }
        ],
        acid: [
            { key: 'dissolveChance', label: 'Dissolve Rate', min: 0, max: 1.0, step: 0.01 },
            { key: 'sinkChance', label: 'Sink Rate', min: 0, max: 1.0, step: 0.05 },
            { key: 'dispersion', label: 'Spread Speed', min: 1, max: 10, step: 1 },
            { key: 'explodeTNT', type: 'checkbox', label: 'Explode TNT' },
            { key: 'dissolve', subkey: 'rock', type: 'checkbox', label: 'Dissolve Rock' },
            { key: 'dissolve', subkey: 'wood', type: 'checkbox', label: 'Dissolve Wood' },
            { key: 'dissolve', subkey: 'dirt', type: 'checkbox', label: 'Dissolve Dirt' },
            { key: 'dissolve', subkey: 'sand', type: 'checkbox', label: 'Dissolve Sand' },
            { key: 'dissolve', subkey: 'plant', type: 'checkbox', label: 'Dissolve Plant' },
            { key: 'dissolve', subkey: 'grass', type: 'checkbox', label: 'Dissolve Grass' },
            { key: 'dissolve', subkey: 'water', type: 'checkbox', label: 'Infect Water' },
            { key: 'dissolve', subkey: 'ice', type: 'checkbox', label: 'Dissolve Ice' },
            { key: 'dissolve', subkey: 'oil', type: 'checkbox', label: 'Dissolve Oil' }
        ],
        fire: [
            { key: 'burnChance', label: 'Fire Decay Rate', min: 0, max: 1.0, step: 0.01 }
        ],
        water: [
            { key: 'flowChance', label: 'Flow Rate', min: 0, max: 1.0, step: 0.05 },
            { key: 'dispersion', label: 'Spread Speed', min: 1, max: 10, step: 1 }
        ],
        lava: [
            { key: 'flowChance', label: 'Flow Rate', min: 0, max: 1.0, step: 0.05 },
            { key: 'dispersion', label: 'Spread Speed', min: 1, max: 6, step: 1 },
            { key: 'coolingChance', label: 'Cooling Rate', min: 0, max: 1.0, step: 0.01 },
            { key: 'sinkChance', label: 'Sink in Water', min: 0, max: 1.0, step: 0.05 }
        ],
        oil: [
            { key: 'flowChance', label: 'Flow Rate', min: 0, max: 1.0, step: 0.05 },
            { key: 'dispersion', label: 'Spread Speed', min: 1, max: 8, step: 1 },
            { key: 'burnChance', label: 'Burn Rate', min: 0, max: 1.0, step: 0.01 },
            { key: 'sinkChance', label: 'Water Sink Rate', min: 0, max: 1.0, step: 0.05 },
            { key: 'floatChance', label: 'Oil Float Rate', min: 0, max: 1.0, step: 0.05 }
        ],
        ice: [
            { key: 'meltChance', label: 'Melt Rate', min: 0, max: 1.0, step: 0.01 },
            { key: 'freezeChance', label: 'Freeze Rate', min: 0, max: 1.0, step: 0.01 }
        ],
        steam: [
            { key: 'condenseChance', label: 'Condense Rate', min: 0, max: 1.0, step: 0.01 }
        ],
        smoke: [
            { key: 'dissipateChance', label: 'Dissipate Rate', min: 0, max: 1.0, step: 0.01 }
        ],
        plant: [
            { key: 'growChance', label: 'Growth Rate', min: 0, max: 1.0, step: 0.01 },
            { key: 'woodificationChance', label: 'Wood Rate', min: 0, max: 1.0, step: 0.01 },
            { key: 'burnChance', label: 'Burn Rate', min: 0, max: 1.0, step: 0.05 }
        ],
        grass: [
            { key: 'growChance', label: 'Growth Rate', min: 0, max: 1.0, step: 0.01 },
            { key: 'burnChance', label: 'Burn Rate', min: 0, max: 1.0, step: 0.05 }
        ],
        wood: [
            { key: 'burnChance', label: 'Burn Rate', min: 0, max: 1.0, step: 0.01 }
        ],
        visual: [
            { key: 'style', type: 'radio', label: 'Style', options: ['blocky', 'bloby', 'fuzzy'] },
            { key: 'colorNoise', type: 'checkbox', label: 'Multi-Tone Shading' }
        ]
    };

    for (const [groupName, settings] of Object.entries(groups)) {
        const groupDiv = document.createElement('div');
        groupDiv.className = 'setting-group';
        const title = document.createElement('h3');
        title.textContent = groupName.charAt(0).toUpperCase() + groupName.slice(1);
        groupDiv.appendChild(title);

        settings.forEach(s => {
            groupDiv.appendChild(addControl(groupName, s.key, s.subkey, s));
        });
        container.appendChild(groupDiv);
    }

    // Reset Defaults
    const resetBtn = document.createElement('button');
    resetBtn.className = 'reset-defaults-btn';
    resetBtn.textContent = '↺ Reset to Defaults';
    resetBtn.onclick = () => {
        setConfig(JSON.parse(JSON.stringify(defaultConfig)));
        setBrushSize(defaultConfig.brush.size);
        saveSettings();
        updateBrushUI();
        renderSettings(container);
    };
    container.appendChild(resetBtn);
}

// Bresenham's line algorithm for continuous stroke drawing without gaps
export function handleInput(e, overrideType = null) {
    const rect = canvas.getBoundingClientRect();
    const typeToSpawn = overrideType || selectedType;

    function getGridCoords(clientX, clientY) {
        const x = clientX - rect.left;
        const y = clientY - rect.top;
        return {
            col: Math.floor(x / cellSize),
            row: Math.floor(y / cellSize)
        };
    }

    function stampCircle(centerCol, centerRow) {
        const r = brushSize;
        const rSq = r * r;
        for (let di = -r; di <= r; di++) {
            for (let dj = -r; dj <= r; dj++) {
                if (di * di + dj * dj <= rSq) {
                    const c = centerCol + di;
                    const ro = centerRow + dj;
                    if (c >= 0 && c < cols && ro >= 0 && ro < rows) {
                        if (r <= 2 || Math.random() > 0.08) {
                            spawnCell(c, ro, typeToSpawn);
                        }
                    }
                }
            }
        }
    }

    function drawLine(p0, p1) {
        let x0 = p0.col, y0 = p0.row;
        let x1 = p1.col, y1 = p1.row;

        const dx = Math.abs(x1 - x0);
        const dy = Math.abs(y1 - y0);
        const sx = x0 < x1 ? 1 : -1;
        const sy = y0 < y1 ? 1 : -1;
        let err = dx - dy;

        while (true) {
            stampCircle(x0, y0);
            if (x0 === x1 && y0 === y1) break;
            const e2 = 2 * err;
            if (e2 > -dy) {
                err -= dy;
                x0 += sx;
            }
            if (e2 < dx) {
                err += dx;
                y0 += sy;
            }
        }
    }

    if (e.type.startsWith('mouse')) {
        const current = getGridCoords(e.clientX, e.clientY);
        if (lastPos && (lastPos.col !== current.col || lastPos.row !== current.row)) {
            drawLine(lastPos, current);
        } else {
            stampCircle(current.col, current.row);
        }
        lastPos = current;
    } else if (e.type.startsWith('touch')) {
        for (let i = 0; i < e.touches.length; i++) {
            const t = e.touches[i];
            const current = getGridCoords(t.clientX, t.clientY);
            if (lastPos) {
                drawLine(lastPos, current);
            } else {
                stampCircle(current.col, current.row);
            }
            lastPos = current;
        }
    }
}