const PageScene = {
    _el: null,
    _currentGameId: null,
    _currentGameName: '',
    _editorSceneId: null,
    _editorCanvasIdx: 0,
    _placements: [],
    _dashboards: [],
    _dragItem: null,
    _dragOffsetX: 0,
    _dragOffsetY: 0,
    _resizeItem: null,
    _resizeDir: '',

    init() {
        this._el = document.getElementById('page-scene');
    },

    async render() {
        const cfg = await API.getConfig();
        this._currentGameId = cfg.selected_game_id;
        if (this._currentGameId) {
            const games = await API.getGames();
            const game = games.find(g => g.id === this._currentGameId);
            this._currentGameName = game ? game.name : this._currentGameId;
            this._dashboards = await API.getDashboards('all');
        }
        this._el.innerHTML = this._template();
        this._showSceneList();
        this._bindEvents();
    },

    async _showSceneList() {
        document.getElementById('scene-list-container').style.display = 'block';
        document.getElementById('scene-editor-container').style.display = 'none';
        const grid = document.getElementById('scene-grid');
        if (!grid) return;
        try {
            const scenes = await API.getScenes(this._currentGameId);
            if (!scenes || scenes.length === 0) {
                grid.innerHTML = `<div class="empty-state" style="grid-column:1/-1"><h4>暂无场景</h4><p>点击"新建场景"创建你的场景</p></div>`;
                return;
            }
            grid.innerHTML = scenes.map(s => this._sceneCardHtml(s)).join('');
        } catch (e) { grid.innerHTML = '<div class="empty-state"><p>加载失败</p></div>'; }
    },

    async _openEditor(sceneId) {
        this._editorSceneId = sceneId;
        this._editorCanvasIdx = 0;
        this._placements = [];
        let scene = null;
        if (sceneId) {
            scene = await API.getScene(sceneId);
            if (scene && scene.canvases && scene.canvases[0]) {
                this._placements = scene.canvases[0].placements || [];
            }
        }
        const listC = document.getElementById('scene-list-container');
        const editorC = document.getElementById('scene-editor-container');
        listC.style.display = 'none';
        editorC.style.display = 'flex';
        this._renderCanvasEditor(scene);
    },

    _renderCanvasEditor(scene) {
        const nameInput = document.getElementById('edit-scene-name');
        if (nameInput && scene) nameInput.value = scene.name || '';
        this._renderDashboardList();
        this._renderCanvas();
    },

    _renderDashboardList() {
        const list = document.getElementById('editor-dash-list');
        if (!list) return;
        const filtered = this._dashboards.filter(d => d.supported_games === 'all' || (d.supported_games||'').split(',').includes(this._currentGameId));
        list.innerHTML = filtered.map(d =>
            `<div class="glass-card editor-dash-item" draggable="true" data-dash-id="${d.id}" style="padding:10px;margin-bottom:6px;cursor:grab;font-size:13px;display:flex;align-items:center;gap:8px">
                <span>${d.icon||'📊'}</span>
                <span style="flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">${d.name}</span>
            </div>`
        ).join('') || '<p style="color:var(--text-tertiary);font-size:12px">无兼容仪表盘</p>';

        list.querySelectorAll('.editor-dash-item').forEach(el => {
            el.addEventListener('dragstart', (e) => {
                this._dragItem = { dashId: el.dataset.dashId, isNew: true };
            });
        });
    },

    _renderCanvas() {
        const canvas = document.getElementById('editor-canvas');
        if (!canvas) return;
        const cw = 1920, ch = 1080;
        const scale = Math.min(canvas.parentElement.clientWidth / cw, 1);
        canvas.style.width = (cw * scale) + 'px';
        canvas.style.height = (ch * scale) + 'px';

        canvas.innerHTML = this._placements.map((p, idx) => {
            const dash = this._dashboards.find(d => d.id === p.dashboard_id);
            const name = dash ? dash.name : p.dashboard_id;
            const icon = dash ? (dash.icon || '📊') : '❓';
            return `<div class="editor-placement" data-idx="${idx}" style="left:${p.x*scale}px;top:${p.y*scale}px;width:${p.width*scale}px;height:${p.height*scale}px;z-index:${p.z_index||0}">
                <div class="ep-icon">${icon}</div>
                <div class="ep-name">${name}</div>
                <div class="ep-actions">
                    <button class="btn btn-sm btn-danger" data-action="remove-place" data-idx="${idx}">×</button>
                </div>
            </div>`;
        }).join('');

        canvas.querySelectorAll('.editor-placement').forEach(el => {
            const idx = parseInt(el.dataset.idx);
            el.addEventListener('mousedown', (e) => this._startDragPlace(e, idx, el));
            el.addEventListener('click', (e) => {
                if (e.target.closest('[data-action="remove-place"]')) {
                    this._placements.splice(idx, 1);
                    this._renderCanvas();
                }
            });
        });

        canvas.addEventListener('dragover', (e) => e.preventDefault());
        canvas.addEventListener('drop', (e) => {
            e.preventDefault();
            const rect = canvas.getBoundingClientRect();
            const x = (e.clientX - rect.left) / scale;
            const y = (e.clientY - rect.top) / scale;
            if (this._dragItem && this._dragItem.isNew) {
                this._placements.push({
                    dashboard_id: this._dragItem.dashId,
                    x, y, width: 300, height: 200, z_index: this._placements.length
                });
                this._renderCanvas();
            }
        });
    },

    _startDragPlace(e, idx, el) {
        if (e.target.closest('button')) return;
        const canvasEl = document.getElementById('editor-canvas');
        const rect = canvasEl.getBoundingClientRect();
        const scale = parseFloat(canvasEl.style.width) / 1920;
        const startX = e.clientX, startY = e.clientY;
        const origP = { ...this._placements[idx] };

        const onMove = (ev) => {
            const dx = (ev.clientX - startX) / scale;
            const dy = (ev.clientY - startY) / scale;
            this._placements[idx].x = origP.x + dx;
            this._placements[idx].y = origP.y + dy;
            el.style.left = (this._placements[idx].x * scale) + 'px';
            el.style.top = (this._placements[idx].y * scale) + 'px';
        };
        const onUp = () => {
            document.removeEventListener('mousemove', onMove);
            document.removeEventListener('mouseup', onUp);
        };
        document.addEventListener('mousemove', onMove);
        document.addEventListener('mouseup', onUp);
    },

    async _saveScene() {
        const name = document.getElementById('edit-scene-name')?.value || 'New Scene';
        const data = {
            name,
            game_id: this._currentGameId || '',
            canvases: [{ width: 1920, height: 1080, label: '16:9', placements: this._placements }]
        };
        try {
            if (this._editorSceneId) {
                await API.updateScene(this._editorSceneId, data);
            } else {
                const created = await API.createScene(data);
                this._editorSceneId = created.id;
            }
            Toast.show('场景保存成功', 'success');
            this._showSceneList();
        } catch (e) { Toast.show('保存失败: ' + e.message, 'error'); }
    },

    _bindEvents() {
        document.getElementById('btn-new-scene')?.addEventListener('click', () => this._openEditor(null));
        document.getElementById('btn-import-scene')?.addEventListener('click', () => {
            const input = document.createElement('input'); input.type = 'file'; input.accept = '.tss';
            input.onchange = async (e) => {
                const file = e.target.files[0]; if (!file) return;
                const fd = new FormData(); fd.append('file', file);
                const res = await fetch('/api/scenes/import', { method: 'POST', body: fd });
                const data = await res.json();
                if (data.ok) { Toast.show('场景导入成功', 'success'); this._showSceneList(); }
                else Toast.show('导入失败', 'error');
            }; input.click();
        });

        document.getElementById('btn-back-to-list')?.addEventListener('click', () => this._showSceneList());
        document.getElementById('btn-save-scene')?.addEventListener('click', () => this._saveScene());

        document.getElementById('scene-grid')?.addEventListener('click', (e) => {
            const card = e.target.closest('[data-scene-id]');
            if (!card) return;
            const action = card.dataset.action, sceneId = card.dataset.sceneId;
            if (action === 'render') this._renderScene(sceneId);
            else if (action === 'edit') this._openEditor(sceneId);
            else if (action === 'delete') { if (confirm('确定删除？')) { API.deleteScene(sceneId); this._showSceneList(); } }
            else if (action === 'export') { const a = document.createElement('a'); a.href = '/api/scenes/' + sceneId + '/export'; a.download = sceneId + '.tss'; a.click(); }
        });
    },

    _renderScene(sceneId) {
        const url = `${location.origin}/scene/${sceneId}`;
        window.open(url, '_blank');
        navigator.clipboard.writeText(url).then(() => Toast.show('链接已复制', 'success')).catch(() => {});
    },

    _sceneCardHtml(scene) {
        const canvasCount = (scene.canvases || []).length;
        const preview = scene.preview_ext ? `/scene/${scene.id}/preview.${scene.preview_ext}` : '';
        return `<div class="glass-card scene-card" data-scene-id="${scene.id}" data-action="render">
            ${preview ? `<div style="height:120px;background:url(${preview}) center/cover;border-radius:8px 8px 0 0"></div>` : ''}
            <div class="scene-card-name" style="${preview?'':'padding-top:18px'}">${scene.name}</div>
            <div class="scene-card-game" style="margin-bottom:6px">${this._currentGameName || '未关联游戏'}</div>
            <div class="scene-card-meta"><span>${canvasCount} 画布</span><span>${scene.updated_at ? new Date(scene.updated_at).toLocaleDateString() : ''}</span></div>
            <div class="scene-canvas-list">${(scene.canvases||[]).map(c => `<span class="scene-canvas-badge">${c.label||c.width+'x'+c.height}</span>`).join('')}</div>
            <div style="margin-top:12px;display:flex;gap:6px;flex-wrap:wrap">
                <button class="btn btn-sm btn-primary" data-scene-id="${scene.id}" data-action="render">渲染</button>
                <button class="btn btn-sm btn-secondary" data-scene-id="${scene.id}" data-action="edit">编辑</button>
                <button class="btn btn-sm btn-secondary" data-scene-id="${scene.id}" data-action="export">导出</button>
                <button class="btn btn-sm btn-danger" data-scene-id="${scene.id}" data-action="delete">删除</button>
            </div></div>`;
    },

    _template() {
        return `
        <div class="scene-header animated" id="scene-list-container">
            <div>
                <h2>场景管理</h2>
                <p style="color:var(--text-secondary);font-size:14px;margin-top:4px">${this._currentGameId ? `当前游戏: ${this._currentGameName}` : '请先在侧边栏选择一个游戏'}</p>
            </div>
            <div style="display:flex;gap:8px">
                <button id="btn-import-scene" class="btn btn-secondary btn-sm">导入 .tss</button>
                <button id="btn-new-scene" class="btn btn-primary btn-sm" ${!this._currentGameId ? 'disabled' : ''}>+ 新建场景</button>
            </div>
        </div>
        <div id="scene-grid" class="scene-grid animated"></div>

        <div id="scene-editor-container" style="display:none;flex-direction:column;height:100%">
            <div style="display:flex;align-items:center;justify-content:space-between;margin-bottom:12px">
                <div style="display:flex;align-items:center;gap:12px">
                    <button id="btn-back-to-list" class="btn btn-sm btn-secondary">← 返回</button>
                    <input id="edit-scene-name" placeholder="场景名称" style="font-size:18px;font-weight:600;width:250px" value="New Scene">
                </div>
                <button id="btn-save-scene" class="btn btn-primary btn-sm">保存场景</button>
            </div>
            <div style="display:flex;gap:12px;flex:1;min-height:0">
                <div style="width:180px;flex-shrink:0;overflow-y:auto;border-right:1px solid var(--border-subtle);padding-right:10px">
                    <h4 style="font-size:13px;color:var(--text-secondary);margin-bottom:10px">仪表盘列表 (拖到画布)</h4>
                    <div id="editor-dash-list"></div>
                </div>
                <div style="flex:1;overflow:auto;background:var(--bg-tertiary);border-radius:8px;position:relative">
                    <div id="editor-canvas" style="position:relative;background:rgba(255,255,255,.02);margin:0 auto;overflow:hidden;transition:width 0.2s,height 0.2s"></div>
                </div>
            </div>
        </div>`;
    }
};

window.PageScene = PageScene;