/**
 * Agent Mode Selector Component
 *
 * 在 ChatInput 左侧显示，点击切换三种模式：
 * - Plan: 调用 plan agent，只读分析
 * - Ask: 调用 general agent，执行操作需确认
 * - Auto: 调用 general agent，自动执行无需确认
 */

import { FileSearch, MessageCircleQuestion, Zap } from 'lucide-react';
import clsx from 'clsx';

export type AgentModeType = 'build' | 'plan';

/** 组合模式：Plan / Ask / Auto */
export type CombinedModeType = 'plan' | 'ask' | 'auto';

interface AgentModeSelectorProps {
  /** 当前模式 */
  mode: AgentModeType;
  /** 模式变更回调 */
  onModeChange: (mode: AgentModeType) => void;
  /** 是否自动授权文件写入/编辑 */
  autoApprove: boolean;
  /** 自动授权变更回调 */
  onAutoApproveChange: (enabled: boolean) => void;
  /** 是否禁用 */
  disabled?: boolean;
}

const modeConfig: Record<
  CombinedModeType,
  {
    label: string;
    icon: typeof FileSearch;
    color: string;
    bgColor: string;
    borderColor: string;
    hoverBg: string;
    description: string;
  }
> = {
  plan: {
    label: 'Plan',
    icon: FileSearch,
    color: 'text-purple-500',
    bgColor: 'bg-purple-500/10',
    borderColor: 'border-purple-500/30',
    hoverBg: 'hover:bg-purple-500/15',
    description: '只读模式，仅分析和规划',
  },
  ask: {
    label: 'Ask',
    icon: MessageCircleQuestion,
    color: 'text-blue-500',
    bgColor: 'bg-blue-500/10',
    borderColor: 'border-blue-500/30',
    hoverBg: 'hover:bg-blue-500/15',
    description: '执行操作前需要确认',
  },
  auto: {
    label: 'Auto',
    icon: Zap,
    color: 'text-orange-500',
    bgColor: 'bg-orange-500/10',
    borderColor: 'border-orange-500/30',
    hoverBg: 'hover:bg-orange-500/15',
    description: '自动执行，无需确认',
  },
};

// 模式切换顺序：Ask -> Auto -> Plan -> Ask ...
const modeOrder: CombinedModeType[] = ['ask', 'auto', 'plan'];

/**
 * 根据 agentMode 和 autoApprove 计算当前组合模式
 */
function getCombinedMode(agentMode: AgentModeType, autoApprove: boolean): CombinedModeType {
  if (agentMode === 'plan') return 'plan';
  return autoApprove ? 'auto' : 'ask';
}

/**
 * 根据组合模式计算 agentMode 和 autoApprove
 */
function getAgentConfig(combinedMode: CombinedModeType): {
  agentMode: AgentModeType;
  autoApprove: boolean;
} {
  switch (combinedMode) {
    case 'plan':
      return { agentMode: 'plan', autoApprove: false };
    case 'ask':
      return { agentMode: 'build', autoApprove: false };
    case 'auto':
      return { agentMode: 'build', autoApprove: true };
  }
}

export function AgentModeSelector({
  mode,
  onModeChange,
  autoApprove,
  onAutoApproveChange,
  disabled = false,
}: AgentModeSelectorProps) {
  // 计算当前组合模式
  const currentCombinedMode = getCombinedMode(mode, autoApprove);
  const currentConfig = modeConfig[currentCombinedMode];
  const ModeIcon = currentConfig.icon;

  // 点击切换到下一个模式
  const handleToggle = () => {
    if (disabled) return;

    // 找到当前模式在顺序中的索引
    const currentIndex = modeOrder.indexOf(currentCombinedMode);
    // 切换到下一个模式
    const nextIndex = (currentIndex + 1) % modeOrder.length;
    const nextMode = modeOrder[nextIndex];

    // 获取新的配置并更新
    const { agentMode, autoApprove: newAutoApprove } = getAgentConfig(nextMode);
    onModeChange(agentMode);
    onAutoApproveChange(newAutoApprove);
  };

  return (
    <button
      type="button"
      onClick={handleToggle}
      disabled={disabled}
      title={`${currentConfig.label}: ${currentConfig.description}（点击切换）`}
      className={clsx(
        'flex items-center gap-1.5 px-2.5 py-1.5 rounded-lg border transition-all duration-200',
        'text-sm font-medium',
        disabled
          ? 'opacity-50 cursor-not-allowed border-line bg-surface-subtle'
          : [
              currentConfig.bgColor,
              currentConfig.borderColor,
              currentConfig.hoverBg,
              'cursor-pointer active:scale-95',
            ],
        currentConfig.color
      )}
    >
      <ModeIcon size={16} />
      <span className="hidden sm:inline">{currentConfig.label}</span>
    </button>
  );
}