// ============================================================
// LeftPanel — 左列容器（模型选择 + 可拖拽分割线 + 任务搜索 + 任务记录）
// 纵向拖拽分隔线支持鼠标调整上下区域高度比例
//
// 职责：布局 + edition 分发，子组件自行管理数据和搜索状态
// ============================================================

import { useState, useRef, useEffect, useCallback } from 'react';
import { theme as antTheme } from 'antd';
import { ModelSelector } from '../features/ModelSelector';
import { TaskHistory } from '../features/TaskHistory';
import { useModelList } from '@/hooks/use-api';

// ---------- 常量 ----------

/** 模型选择区最小高度 */
const TOP_MIN = 120;
/** 任务列表区最小高度 */
const BOTTOM_MIN = 200;
/** 默认模型选择区百分比 */
const TOP_DEFAULT_PCT = 0.40;
/** 拖拽分隔条高度 */
const DIVIDER_HEIGHT = 6;

// ---------- 组件 ----------

export function LeftPanel() {
   const { token } = antTheme.useToken();

   // 面板容器引用
   const containerRef = useRef<HTMLDivElement>(null);

   // ======== 模型数据（提升到父组件，避免两个子组件重复请求） ========
   const { data: models, loading, error, groupedModels, refetch } = useModelList();

   // 模型选择区高度（像素）
   const [topHeight, setTopHeight] = useState<number | null>(null);
   // 拖拽状态
   const [dragging, setDragging] = useState(false);
   // hover 状态
   const [hovered, setHovered] = useState(false);

   const dragState = useRef<{
      startY: number;
      startHeight: number;
   }>({ startY: 0, startHeight: 0 });

   // 初始化：按百分比计算顶部高度
   const initHeight = useCallback(() => {
      const el = containerRef.current;
      if (!el) return;
      const total = el.clientHeight;
      setTopHeight(Math.max(TOP_MIN, Math.round(total * TOP_DEFAULT_PCT)));
   }, []);

   useEffect(() => {
      initHeight();
   }, [initHeight]);

   // 响应容器 resize（窗口大小变化时重新按比例计算）
   useEffect(() => {
      const el = containerRef.current;
      if (!el) return;
      const observer = new ResizeObserver(() => {
         if (!dragging) {
            const total = el.clientHeight;
            setTopHeight((prev) => {
               if (prev === null) return Math.max(TOP_MIN, Math.round(total * TOP_DEFAULT_PCT));
               // 保持原有比例
               const ratio = prev / total;
               return Math.max(TOP_MIN, Math.round(total * Math.min(ratio, 0.8)));
            });
         }
      });
      observer.observe(el);
      return () => observer.disconnect();
   }, [dragging]);

   // 拖拽事件
   const handleDividerMouseDown = (e: React.MouseEvent) => {
      e.preventDefault();
      dragState.current = { startY: e.clientY, startHeight: topHeight ?? 200 };
      setDragging(true);
   };

   useEffect(() => {
      const handleMouseMove = (e: MouseEvent) => {
         if (!dragging) return;

         const el = containerRef.current;
         if (!el) return;

         const total = el.clientHeight;
         const ds = dragState.current;
         const delta = e.clientY - ds.startY;
         const newTop = Math.max(TOP_MIN, Math.min(total - BOTTOM_MIN, ds.startHeight + delta));
         setTopHeight(newTop);
      };

      const handleMouseUp = () => {
         setDragging(false);
      };

      document.addEventListener('mousemove', handleMouseMove);
      document.addEventListener('mouseup', handleMouseUp);

      return () => {
         document.removeEventListener('mousemove', handleMouseMove);
         document.removeEventListener('mouseup', handleMouseUp);
      };
   }, [dragging]);

   // 分隔条样式
   const isActive = dragging;
   const isHovered = hovered;

   return (
      <div
         ref={containerRef}
         style={{
            display: 'flex',
            flexDirection: 'column',
            height: '100%',
            overflow: 'hidden',
            borderRadius: 8,
            border: `1px solid ${token.colorBorderSecondary}`,
         }}
      >
         {/* 上方：模型选择（高度由拖拽控制） */}
         <div
            style={{
               height: topHeight ?? '40%',
               overflow: 'hidden',
               display: 'flex',
               flexDirection: 'column',
               flexShrink: 0,
            }}
         >
            <ModelSelector
               models={models}
               loading={loading}
               error={error}
               groupedModels={groupedModels}
               refetch={refetch}
            />
         </div>

         {/* 纵向拖拽分隔条 */}
         <div
            onMouseDown={handleDividerMouseDown}
            style={{
               height: DIVIDER_HEIGHT,
               flexShrink: 0,
               cursor: 'row-resize',
               background: isActive
                  ? token.colorPrimary
                  : isHovered
                     ? `${token.colorPrimary}60`
                     : token.colorBorderSecondary,
               display: 'flex',
               alignItems: 'center',
               justifyContent: 'center',
               transition: 'background 0.15s linear',
               zIndex: 10,
            }}
            onMouseEnter={() => setHovered(true)}
            onMouseLeave={() => setHovered(false)}
         >
            {/* 拖拽手柄横线 */}
            <div style={{
               height: 2,
               width: 32,
               borderRadius: 1,
               background: isActive
                  ? '#fff'
                  : isHovered
                     ? token.colorPrimary
                     : token.colorBorder,
               transition: 'background 0.15s linear',
            }} />
         </div>

         {/* 下方：任务记录（剩余高度） */}
         <div style={{ flex: 1, overflow: 'hidden', display: 'flex', flexDirection: 'column', minHeight: 0 }}>
            <TaskHistory allModels={models} />
         </div>
      </div>
   );
}