'use client';

import { useState } from 'react';
import { X, Check, Link2, FileUp, ExternalLink, Play, ArrowRightLeft } from 'lucide-react';
import { useVersionPlanStore } from '@/stores/useVersionPlanStore';
import { useRequirementStore } from '@/stores/useRequirementStore';
import { useMemberStore } from '@/stores/useMemberStore';
import { calcPlanProgress, calcLinkedReqProgress } from '@/lib/version-plan';
import { formatDateTime } from '@/lib/format';
import type { PlanTask, VersionPlan } from '@/lib/version-plan';
import { canEditPlanRequirementCoverage, canTogglePlanChecklist, getPlanCompletionState } from '@/lib/version-plan-workflow';

interface Props {
  planId: string;
  onClose: () => void;
  contextLabel?: string;
}

const STATUS_STYLE: Record<string, string> = { pending: 'bg-zinc-100 text-zinc-600', in_progress: 'bg-blue-50 text-blue-600', completed: 'bg-emerald-50 text-emerald-600' };
const STATUS_LABEL: Record<string, string> = { pending: '未开始', in_progress: '进行中', completed: '已完成' };
const TYPE_LABEL: Record<string, string> = { research: '调研', product: '产品方案', ui: 'UI设计' };

export function PlanDetailDrawer({ planId, onClose, contextLabel }: Props) {
  const { plans, updatePlan, completePlan } = useVersionPlanStore();
  const { requirements } = useRequirementStore();
  const { members } = useMemberStore();
  const [showTransfer, setShowTransfer] = useState(false);
  const [transferTo, setTransferTo] = useState('');
  const [resultType, setResultType] = useState<'link' | 'file'>('link');
  const [resultTitle, setResultTitle] = useState('');
  const [resultUrl, setResultUrl] = useState('');
  const [fileName, setFileName] = useState('');
  const [fileData, setFileData] = useState('');
  const [showComplete, setShowComplete] = useState(false);

  const plan = plans.find((p) => p.id === planId);
  if (!plan) return null;

  const completionState = getPlanCompletionState(plan);
  const isResearch = plan.type === 'research';
  const progress = isResearch ? calcPlanProgress(plan.tasks) : calcLinkedReqProgress(plan.linkedRequirementIds, plan.completedRequirementIds);
  const linkedReqs = (plan.linkedRequirementIds || []).map((id) => requirements.find((r) => r.id === id)).filter(Boolean) as { id: string; code: string; title: string }[];
  const canToggle = canTogglePlanChecklist(plan);
  const canEditCoverage = canEditPlanRequirementCoverage(plan);

  const handleToggleTask = (task: PlanTask) => {
    if (!canToggle) return;
    const nextStatus = task.status === 'completed' ? 'pending' : 'completed';
    const updatedTasks = (plan.tasks || []).map((t) => t.id === task.id ? { ...t, status: nextStatus as PlanTask['status'] } : t);
    updatePlan(plan.id, { tasks: updatedTasks });
  };

  const handleToggleReq = (reqId: string) => {
    if (!canEditCoverage) return;
    const current = plan.completedRequirementIds || [];
    const next = current.includes(reqId) ? current.filter((id) => id !== reqId) : [...current, reqId];
    updatePlan(plan.id, { completedRequirementIds: next });
  };

  const handleFile = (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file) return;
    setFileName(file.name);
    const reader = new FileReader();
    reader.onload = () => setFileData(reader.result as string);
    reader.readAsDataURL(file);
  };

  const handleSubmitResult = () => {
    const url = resultType === 'link' ? resultUrl.trim() : fileData;
    const title = resultTitle.trim();
    if (!url || !title) return;
    const response = completePlan(plan.id, { resultType, resultTitle: title, resultUrl: url, resultFileName: fileName || undefined, resultFileData: resultType === 'file' ? fileData : undefined });
    if (response && typeof response === 'object' && 'ok' in response && !response.ok) {
      alert(response.message || '计划未满足完成条件');
      return;
    }
    setShowComplete(false);
  };

  const handleTransfer = () => {
    if (!transferTo) return;
    updatePlan(plan.id, { owner: transferTo });
    setShowTransfer(false);
    setTransferTo('');
  };

  return (
    <div className="fixed inset-0 z-50 flex justify-end" onClick={onClose}>
      <div className="w-full max-w-md h-full bg-[var(--bg)] border-l border-[var(--line)] shadow-2xl flex flex-col overflow-hidden" onClick={(e) => e.stopPropagation()}>
        {/* Context */}
        {contextLabel && (
          <div className="px-5 py-2 border-b border-[var(--line)] bg-[var(--bg-subtle)] shrink-0">
            <span className="text-[11px] text-[var(--ink-muted)]">{contextLabel}</span>
          </div>
        )}
        {/* Header */}
        <div className="flex items-center justify-between px-5 py-4 border-b border-[var(--line)] shrink-0">
          <div className="flex items-center gap-2">
            <span className="text-[10px] font-medium px-2 py-0.5 rounded-full bg-[var(--bg-subtle)] text-[var(--ink-muted)]">{TYPE_LABEL[plan.type]}</span>
            <span className={`text-[10px] font-medium px-2 py-0.5 rounded-full ${STATUS_STYLE[plan.status]}`}>{STATUS_LABEL[plan.status]}</span>
          </div>
          <button onClick={onClose} className="p-1 rounded hover:bg-[var(--bg-subtle)] text-[var(--ink-muted)]"><X className="h-4 w-4" /></button>
        </div>

        {/* Body */}
        <div className="flex-1 overflow-y-auto p-5 space-y-4">
          <h3 className="text-[15px] font-semibold text-[var(--ink)]">{plan.title}</h3>

          {/* Info */}
          <div className="grid grid-cols-2 gap-3 text-[12px]">
            <div>
              <span className="text-[var(--ink-muted)]">负责人</span>
              <div className="font-medium text-[var(--ink)] mt-0.5">{plan.owner}</div>
            </div>
            <div>
              <span className="text-[var(--ink-muted)]">进度</span>
              <div className="font-medium text-[var(--ink)] mt-0.5">{progress}%</div>
            </div>
            <div>
              <span className="text-[var(--ink-muted)]">计划时间</span>
              <div className="font-medium text-[var(--ink)] mt-0.5">{formatDateTime(plan.startTime)} → {formatDateTime(plan.endTime)}</div>
            </div>
            {plan.actualStartAt && (
              <div>
                <span className="text-[var(--ink-muted)]">实际开始</span>
                <div className="font-medium text-blue-600 mt-0.5">{formatDateTime(plan.actualStartAt)}</div>
              </div>
            )}
            {plan.completedAt && (
              <div>
                <span className="text-[var(--ink-muted)]">完成时间</span>
                <div className="font-medium text-emerald-600 mt-0.5">{formatDateTime(plan.completedAt)}</div>
              </div>
            )}
          </div>

          {/* Progress Bar */}
          <div className="h-2 rounded-full bg-[var(--bg-subtle)] overflow-hidden">
            <div className="h-full rounded-full bg-[var(--accent)] transition-all" style={{ width: `${progress}%` }} />
          </div>

          {/* Research Tasks */}
          {isResearch && plan.tasks && plan.tasks.length > 0 && (
            <div className="space-y-1.5">
              <div className="text-[11px] font-medium text-[var(--ink-muted)]">任务清单</div>
              {plan.tasks.map((task) => (
                <div key={task.id} className="flex items-center gap-2 px-2 py-1.5 rounded-lg hover:bg-[var(--bg-subtle)]">
                  <button
                    disabled={!canToggle}
                    onClick={() => handleToggleTask(task)}
                    className={`h-4 w-4 rounded border flex items-center justify-center shrink-0 transition-colors ${!canToggle ? 'opacity-40 cursor-not-allowed' : ''} ${task.status === 'completed' ? 'bg-[var(--accent)] border-[var(--accent)]' : 'border-[var(--line)]'}`}
                  >
                    {task.status === 'completed' && <Check className="h-2.5 w-2.5 text-white" strokeWidth={3} />}
                  </button>
                  <span className={`flex-1 text-[12px] ${task.status === 'completed' ? 'line-through text-[var(--ink-muted)]' : 'text-[var(--ink)]'}`}>{task.title}</span>
                </div>
              ))}
            </div>
          )}

          {/* Product/UI: Linked Requirements */}
          {linkedReqs.length > 0 && (
            <div className="space-y-1.5">
              <div className="text-[11px] font-medium text-[var(--ink-muted)]">关联需求</div>
              {linkedReqs.map((req) => {
                const isDone = (plan.completedRequirementIds || []).includes(req.id);
                return (
                  <div key={req.id} className="flex items-center gap-2 px-2 py-1.5 rounded-lg hover:bg-[var(--bg-subtle)]">
                    <button
                      disabled={!canEditCoverage}
                      onClick={() => handleToggleReq(req.id)}
                      className={`h-4 w-4 rounded border flex items-center justify-center shrink-0 transition-colors ${!canEditCoverage ? 'opacity-40 cursor-not-allowed' : ''} ${isDone ? 'bg-[var(--accent)] border-[var(--accent)]' : 'border-[var(--line)]'}`}
                    >
                      {isDone && <Check className="h-2.5 w-2.5 text-white" strokeWidth={3} />}
                    </button>
                    <span className="text-[11px] font-mono text-[var(--ink-muted)]">{req.code}</span>
                    <span className={`flex-1 text-[12px] ${isDone ? 'line-through text-[var(--ink-muted)]' : 'text-[var(--ink)]'}`}>{req.title}</span>
                  </div>
                );
              })}
              {plan.status === 'in_progress' && !completionState.canSubmitResult && (
                <p className="pt-1 text-[11px] text-[var(--ink-muted)]">还不能提交成果：{completionState.missingReasons.join('、')}</p>
              )}
            </div>
          )}

          {/* Result */}
          {plan.status === 'completed' && plan.resultUrl && (
            <div className="rounded-lg bg-[var(--bg-subtle)] p-3">
              <div className="text-[11px] text-[var(--ink-muted)] mb-1">成果</div>
              <div className="flex items-center gap-1.5">
                {plan.resultType === 'link' ? <Link2 className="h-3 w-3 text-[var(--accent)]" /> : <FileUp className="h-3 w-3 text-[var(--accent)]" />}
                <a href={plan.resultUrl} target="_blank" rel="noopener noreferrer" className="text-[12px] text-[var(--accent)] hover:underline flex items-center gap-1">
                  {plan.resultTitle || plan.resultFileName || '查看成果'}<ExternalLink className="h-3 w-3" />
                </a>
              </div>
            </div>
          )}

          {plan.remark && (
            <div className="rounded-lg bg-[var(--bg-subtle)] p-3">
              <div className="text-[11px] text-[var(--ink-muted)] mb-1">备注</div>
              <div className="text-[12px] text-[var(--ink)]">{plan.remark}</div>
            </div>
          )}

          {/* Transfer Section */}
          {showTransfer && (
            <div className="rounded-lg border border-[var(--line)] p-3 space-y-2">
              <div className="text-[11px] font-medium text-[var(--ink-muted)]">转交给</div>
              <select value={transferTo} onChange={(e) => setTransferTo(e.target.value)} className="h-8 w-full rounded-lg border border-[var(--line)] px-2 text-[12px] focus:border-[var(--accent)] focus:outline-none">
                <option value="">选择人员</option>
                {members.filter((m) => m.name !== plan.owner).map((m) => <option key={m.id} value={m.name}>{m.name}</option>)}
              </select>
              <div className="flex gap-2">
                <button onClick={handleTransfer} disabled={!transferTo} className="h-7 px-3 rounded text-[11px] font-medium bg-blue-500 text-white disabled:opacity-50">确认</button>
                <button onClick={() => setShowTransfer(false)} className="h-7 px-2 text-[11px] text-[var(--ink-muted)]">取消</button>
              </div>
            </div>
          )}

          {/* Complete with result */}
          {showComplete && (
            <div className="rounded-lg border border-emerald-200 bg-emerald-50 p-3 space-y-2">
              <div className="text-[11px] font-medium text-emerald-700">提交成果</div>
              <input value={resultTitle} onChange={(e) => setResultTitle(e.target.value)} placeholder="成果标题（必填，如 v1.0 产品方案）" className="h-8 w-full rounded-lg border border-[var(--line)] px-2 text-[12px] focus:border-[var(--accent)] focus:outline-none" />
              <div className="flex gap-2">
                <button onClick={() => setResultType('link')} className={`h-7 px-2.5 rounded text-[11px] font-medium border ${resultType === 'link' ? 'border-[var(--accent)] text-[var(--accent)]' : 'border-[var(--line)] text-[var(--ink-soft)]'}`}><Link2 className="h-3 w-3 inline mr-1" />链接</button>
                <button onClick={() => setResultType('file')} className={`h-7 px-2.5 rounded text-[11px] font-medium border ${resultType === 'file' ? 'border-[var(--accent)] text-[var(--accent)]' : 'border-[var(--line)] text-[var(--ink-soft)]'}`}><FileUp className="h-3 w-3 inline mr-1" />文件</button>
              </div>
              {resultType === 'link' ? (
                <input value={resultUrl} onChange={(e) => setResultUrl(e.target.value)} placeholder="https://..." className="h-8 w-full rounded-lg border border-[var(--line)] px-2 text-[12px] focus:border-[var(--accent)] focus:outline-none" />
              ) : (
                <div>
                  <input type="file" onChange={handleFile} className="text-[11px] text-[var(--ink-soft)]" />
                  {fileName && <p className="text-[10px] text-[var(--ink-muted)] mt-1">{fileName}</p>}
                </div>
              )}
              <div className="flex gap-2">
                <button onClick={handleSubmitResult} disabled={!completionState.canSubmitResult || !resultTitle.trim() || (resultType === 'link' ? !resultUrl.trim() : !fileData)} className="h-7 px-3 rounded text-[11px] font-medium bg-emerald-500 text-white disabled:opacity-50">确认提交</button>
                <button onClick={() => setShowComplete(false)} className="h-7 px-2 text-[11px] text-[var(--ink-muted)]">取消</button>
              </div>
            </div>
          )}
        </div>

        {/* Footer Actions */}
        {plan.status !== 'completed' && (
          <>
            <div className="flex items-center gap-2 px-5 py-3 border-t border-[var(--line)] shrink-0">
              {plan.status === 'pending' && (
                <button onClick={() => updatePlan(plan.id, { status: 'in_progress' })} className="h-8 px-3 rounded-lg text-[12px] font-medium text-blue-600 border border-blue-200 hover:bg-blue-50 flex items-center gap-1">
                  <Play className="h-3 w-3" />开始
                </button>
              )}
              {plan.status === 'in_progress' && (
                <button onClick={() => setShowComplete(true)} disabled={!completionState.canSubmitResult} className="h-8 px-3 rounded-lg text-[12px] font-medium text-emerald-600 border border-emerald-200 hover:bg-emerald-50 disabled:opacity-50 disabled:cursor-not-allowed">
                  提交完成
                </button>
              )}
              <button onClick={() => setShowTransfer(true)} className="h-8 px-3 rounded-lg text-[12px] font-medium text-[var(--ink-soft)] border border-[var(--line)] hover:bg-[var(--bg-subtle)] flex items-center gap-1">
                <ArrowRightLeft className="h-3 w-3" />转交
              </button>
            </div>
            {plan.status === 'in_progress' && !completionState.canSubmitResult && (
              <div className="px-5 pb-3 text-[11px] text-[var(--ink-muted)]">还不能提交成果：{completionState.missingReasons.join('、')}</div>
            )}
          </>
        )}
      </div>
    </div>
  );
}