// ============================================================
// CanvasPage — 无限画布页面
//
// 两栏 flex 布局（Assets 阶段为单栏）：
//   左侧：ShotList（镜头单选列表）
//   右侧：CanvasViewport（主画布）
//   顶部：CanvasToolbar
//   底部：状态栏
// ============================================================

import { useTheme } from '@/components/providers/ThemeProvider';
import { useCanvasStore } from './store/useCanvasStore';
import { useDirectoryScan } from './hooks/useDirectoryScan';
import { CanvasToolbar } from './toolbar/CanvasToolbar';
import { CanvasViewport } from './core/CanvasViewport';
import { ShotList } from './navigation/ShotList';

/** 中心区域占位提示 */
function Placeholder({
    icon,
    title,
    hint,
    isDark,
}: {
    icon: string;
    title: string;
    hint: string;
    isDark: boolean;
}) {
    return (
        <div
            style={{
                flex: 1,
                display: 'flex',
                flexDirection: 'column',
                alignItems: 'center',
                justifyContent: 'center',
            }}
        >
            <div style={{ fontSize: 48, marginBottom: 16 }}>{icon}</div>
            <div style={{ fontSize: 14, color: isDark ? '#A5A3C0' : '#6B7280' }}>{title}</div>
            <div
                style={{
                    fontSize: 12,
                    marginTop: 8,
                    color: isDark ? '#6E6B90' : '#9CA3AF',
                }}
            >
                {hint}
            </div>
        </div>
    );
}

export function CanvasPage() {
    const { isDark } = useTheme();
    const workspaceRoot = useCanvasStore((s) => s.workspaceRoot);
    const selectedProject = useCanvasStore((s) => s.selectedProject);
    const selectedEpisode = useCanvasStore((s) => s.selectedEpisode);
    const selectedShot = useCanvasStore((s) => s.selectedShot);
    const items = useCanvasStore((s) => s.items);
    const isScanning = useCanvasStore((s) => s.isScanning);
    const currentStage = useCanvasStore((s) => s.currentStage);

    // 启动目录扫描监听
    useDirectoryScan();

    const isAssets = currentStage === 'Assets';

    /** 根据当前选中状态决定主视图内容 */
    const renderMainContent = () => {
        if (!workspaceRoot) {
            return (
                <Placeholder
                    icon="📂"
                    title="请先选择一个工作区目录"
                    hint="目录结构需符合 AIGC 生产管线约定（项目/shots/集数/镜头/阶段）"
                    isDark={isDark}
                />
            );
        }

        if (!selectedProject) {
            return (
                <Placeholder
                    icon="📁"
                    title="请先选择一个项目"
                    hint="从顶部工具栏的项目下拉列表中选择"
                    isDark={isDark}
                />
            );
        }

        if (isScanning) {
            return (
                <div
                    style={{
                        flex: 1,
                        display: 'flex',
                        flexDirection: 'column',
                        alignItems: 'center',
                        justifyContent: 'center',
                    }}
                >
                    <div style={{ fontSize: 32, marginBottom: 12 }}>🔍</div>
                    <div style={{ fontSize: 14 }}>正在扫描文件…</div>
                </div>
            );
        }

        if (!isAssets && !selectedEpisode) {
            return (
                <Placeholder
                    icon="🎬"
                    title="请先选择集数"
                    hint="从顶部工具栏的集数下拉列表中选择"
                    isDark={isDark}
                />
            );
        }

        if (!isAssets && !selectedShot) {
            return (
                <Placeholder
                    icon="🎞️"
                    title="请先选择镜头"
                    hint="从左侧镜头列表中点击选择"
                    isDark={isDark}
                />
            );
        }

        if (items.length === 0) {
            return (
                <Placeholder
                    icon="📭"
                    title={`当前阶段「${currentStage}」没有匹配的文件`}
                    hint="请确认目录结构，或切换阶段标签"
                    isDark={isDark}
                />
            );
        }

        return <CanvasViewport />;
    };

    return (
        <div
            style={{
                width: '100vw',
                height: '100vh',
                display: 'flex',
                flexDirection: 'column',
                background: isDark ? '#0F0D1E' : '#F5F3FF',
                color: isDark ? '#E8E6F0' : '#1E1B4B',
                overflow: 'hidden',
            }}
        >
            {/* 顶部工具栏 */}
            <CanvasToolbar />

            {/* 中心区域：两栏布局 */}
            <div
                style={{
                    flex: 1,
                    display: 'flex',
                    overflow: 'hidden',
                }}
            >
                {/* 左侧镜头列表（Assets 阶段隐藏） */}
                <ShotList />

                {/* 右侧主内容 */}
                <div
                    style={{
                        flex: 1,
                        display: 'flex',
                        overflow: 'hidden',
                    }}
                >
                    {renderMainContent()}
                </div>
            </div>

            {/* 底部状态栏 */}
            <div
                style={{
                    height: 28,
                    flexShrink: 0,
                    display: 'flex',
                    alignItems: 'center',
                    padding: '0 12px',
                    borderTop: `1px solid ${isDark ? '#2E2A5A' : '#E5E7EB'}`,
                    background: isDark ? '#15132E' : '#EEF2FF',
                    fontSize: 11,
                    color: isDark ? '#6E6B90' : '#9CA3AF',
                }}
            >
                <span>离线模式 · 本地文件系统</span>
                <span style={{ margin: '0 8px' }}>|</span>
                <span>
                    {isScanning
                        ? '扫描中…'
                        : workspaceRoot
                            ? `项目：${selectedProject || '(未选)'} · 阶段：${currentStage} · ${items.length} 个文件`
                            : '准备就绪'}
                </span>
                {selectedEpisode && (
                    <>
                        <span style={{ margin: '0 4px' }}>|</span>
                        <span>集数：{selectedEpisode}</span>
                    </>
                )}
                {selectedShot && (
                    <>
                        <span style={{ margin: '0 4px' }}>|</span>
                        <span>镜头：{selectedShot}</span>
                    </>
                )}
                <span style={{ flex: 1 }} />
                <span>Phase 1</span>
            </div>
        </div>
    );
}