'use client';

import { useState, useMemo, useEffect } from 'react';
import { Bug as BugIcon, Filter } from 'lucide-react';
import { useBugStore } from '@/stores/useBugStore';
import { useTestCaseStore } from '@/stores/useTestCaseStore';
import { useRequirementStore } from '@/stores/useRequirementStore';
import { useAuthStore } from '@/stores/useAuthStore';
import { useMemberStore } from '@/stores/useMemberStore';
import { BugRow } from './BugRow';
import { BugDetailDrawer } from './BugDetailDrawer';
import { Pagination, usePagination } from '@/components/Pagination';
import { FilterSelect } from '@/components/FilterSelect';
import { SearchInput, matchTitleOrNo } from '@/components/SearchInput';
import { useDebouncedValue } from '@/hooks/useDebouncedValue';
import { BUG_STATUS_LABEL, BUG_SEVERITY_LABEL, aggregateBugActualHours, bugIntervals } from '@/lib/bug';
import { calcTwoMetrics } from '@/lib/work-hours';
import { isMemberReference, resolveMemberDisplayName } from '@/lib/member-system';
import { buildEffortSummaryMetrics, sumPositiveHours } from '@/lib/effort-summary';
import type { Bug, BugStatus, BugSeverity } from '@/lib/bug';
import type { TestCase } from '@/lib/test-case';

interface Props {
  versionId: string;
  requirementIds: string[];
  readOnly?: boolean;
  versionBugs?: Bug[];
  versionTestCases?: TestCase[];
}

export function BugTab({ versionId, requirementIds, readOnly = false, versionBugs: scopedVersionBugs, versionTestCases }: Props) {
  const { bugs, fetchBugs } = useBugStore();
  const { testCases, fetchTestCases } = useTestCaseStore();
  const { requirements } = useRequirementStore();
  const user = useAuthStore((s) => s.user);
  const members = useMemberStore((s) => s.members);

  useEffect(() => {
    if (!scopedVersionBugs) fetchBugs();
  }, [fetchBugs, scopedVersionBugs]);
  useEffect(() => {
    if (!versionTestCases) fetchTestCases();
  }, [fetchTestCases, versionTestCases]);

  const fallbackVersionBugs = useMemo(
    () => bugs.filter((b) => b.versionId === versionId),
    [bugs, versionId],
  );
  const versionBugs = scopedVersionBugs ?? fallbackVersionBugs;

  const openCount = versionBugs.filter((b) => b.status === 'open').length;
  const fixingCount = versionBugs.filter((b) => b.status === 'fixing').length;
  const fixedCount = versionBugs.filter((b) => b.status === 'fixed' || b.status === 'verifying').length;
  const closedCount = versionBugs.filter((b) => b.status === 'closed' || b.status === 'rejected').length;
  const criticalCount = versionBugs.filter((b) => b.severity === 'critical' && b.status !== 'closed' && b.status !== 'rejected').length;
  const resolveRate = versionBugs.length > 0 ? Math.round(((fixedCount + closedCount) / versionBugs.length) * 100) : 0;
  const bugActualHours = useMemo(() => aggregateBugActualHours(versionBugs), [versionBugs]);
  const { manhours: bugManhours } = useMemo(() => calcTwoMetrics(bugIntervals(versionBugs)), [versionBugs]);
  const effortMetrics = useMemo(
    () => buildEffortSummaryMetrics({
      aiEstimateHours: sumPositiveHours(versionBugs, (bug) => bug.aiEstimateHours),
      estimateHours: sumPositiveHours(versionBugs, (bug) => bug.estimateHours),
      actualHours: bugActualHours,
      manhours: bugManhours,
    }),
    [versionBugs, bugActualHours, bugManhours],
  );

  const [filterAssignee, setFilterAssignee] = useState('');
  const [filterStatus, setFilterStatus] = useState('');
  const [filterSeverity, setFilterSeverity] = useState('');
  const [keyword, setKeyword] = useState('');
  const debouncedKeyword = useDebouncedValue(keyword, 300);

  const [selectedBugId, setSelectedBugId] = useState<string | null>(null);

  const visibleTestCases = versionTestCases ?? testCases;
  const testCaseMap = useMemo(() => new Map(visibleTestCases.map((c) => [c.id, c])), [visibleTestCases]);
  const currentMember = useMemo(() => members.find((m) => m.id === user?.id), [members, user?.id]);
  const currentUserName = currentMember?.name ?? user?.name;

  const assignees = useMemo(() => {
    const names = new Set(versionBugs.map((b) => resolveMemberDisplayName(b.assigneeId, members)));
    return Array.from(names);
  }, [versionBugs, members]);

  const filteredBugs = useMemo(() => {
    let result = versionBugs;
    if (filterAssignee === '__me') {
      if (currentMember) {
        result = result.filter((b) => isMemberReference(b.assigneeId, currentMember));
      } else {
        result = [];
      }
    } else if (filterAssignee) {
      result = result.filter((b) => resolveMemberDisplayName(b.assigneeId, members) === filterAssignee);
    }
    if (filterStatus) result = result.filter((b) => b.status === filterStatus);
    if (filterSeverity) result = result.filter((b) => b.severity === filterSeverity);
    if (debouncedKeyword) result = result.filter((b) => matchTitleOrNo({ title: b.title, no: b.bugNo }, debouncedKeyword));
    return result;
  }, [versionBugs, filterAssignee, filterStatus, filterSeverity, debouncedKeyword, currentMember, members]);

  const { paged, page, setPage, total, pageSize, setPageSize } = usePagination(filteredBugs, 20);

  const hasFilter = !!(filterAssignee || filterStatus || filterSeverity || debouncedKeyword);

  return (
    <div className="space-y-3">
      <div className="flex items-center gap-4 px-4 py-3 rounded-lg bg-[var(--bg-subtle)] border border-[var(--line)] flex-wrap">
        <div className="flex items-center gap-2">
          <BugIcon className="h-4 w-4 text-red-500" />
          <span className="text-[13px] font-medium text-[var(--ink)]">Bug {versionBugs.length} 个</span>
        </div>
        <span className="text-[11px] text-[var(--ink-muted)] tabular-nums">
          待修复 {openCount} · 修复中 {fixingCount} · 已修复 {fixedCount} · 已关闭 {closedCount}
        </span>
        {criticalCount > 0 && (
          <span className="text-[11px] text-red-600 bg-red-50 px-1.5 py-0.5 rounded font-medium">{criticalCount} 致命</span>
        )}
        <span className="text-[11px] text-[var(--ink-muted)]">解决率 {resolveRate}%</span>
        {effortMetrics.map((metric) => (
          <span key={metric.label} className="text-[11px] text-[var(--ink-muted)] shrink-0">
            {metric.label} <span className="tabular-nums text-[var(--ink)]">{metric.value}</span>
          </span>
        ))}
      </div>

      <div className="flex items-center gap-2 px-1 flex-wrap">
        <Filter className="h-3.5 w-3.5 text-[var(--ink-muted)]" />
        <SearchInput value={keyword} onChange={(v) => { setKeyword(v); setPage(1); }} placeholder="搜索标题/编号" />
        <FilterSelect
          value={filterAssignee || 'all'}
          onChange={(value) => { setFilterAssignee(value === 'all' ? '' : value); setPage(1); }}
          options={[
            ...(currentMember ? [{ value: '__me', label: '我的Bug' }] : []),
            ...assignees.filter((assignee) => assignee !== currentUserName).map((assignee) => ({ value: assignee, label: assignee })),
          ]}
          allLabel="全部修复人"
        />
        <FilterSelect
          value={filterStatus || 'all'}
          onChange={(value) => { setFilterStatus(value === 'all' ? '' : value); setPage(1); }}
          options={(Object.entries(BUG_STATUS_LABEL) as [BugStatus, string][]).map(([value, label]) => ({ value, label }))}
          allLabel="全部状态"
        />
        <FilterSelect
          value={filterSeverity || 'all'}
          onChange={(value) => { setFilterSeverity(value === 'all' ? '' : value); setPage(1); }}
          options={(Object.entries(BUG_SEVERITY_LABEL) as [BugSeverity, string][]).map(([value, label]) => ({ value, label }))}
          allLabel="全部严重程度"
        />
        {hasFilter && <button onClick={() => { setFilterAssignee(''); setFilterStatus(''); setFilterSeverity(''); setKeyword(''); setPage(1); }} className="text-[11px] text-[var(--accent)] hover:underline">清除</button>}
        <span className="ml-auto text-[11px] text-[var(--ink-muted)]">{filteredBugs.length} 条</span>
      </div>

      {filteredBugs.length === 0 ? (
        <div className="rounded-xl border border-dashed border-[var(--line)] bg-[var(--bg-card)] p-12 text-center">
          <p className="text-[13px] text-[var(--ink-muted)]">{hasFilter ? '没有匹配的 Bug' : '暂无 Bug，很好'}</p>
        </div>
      ) : (
        <div className="rounded-lg border border-[var(--line)] bg-[var(--bg-card)] overflow-hidden">
          {paged.map((bug) => {
            const tc = testCaseMap.get(bug.testCaseId);
            return <BugRow key={bug.id} bug={bug} testCaseNo={tc?.caseNo} onClick={() => setSelectedBugId(bug.id)} />;
          })}
        </div>
      )}

      {total > 20 && <Pagination total={total} page={page} pageSize={pageSize} onChange={setPage} onPageSizeChange={setPageSize} />}

      {selectedBugId && <BugDetailDrawer bugId={selectedBugId} readOnly={readOnly} onClose={() => setSelectedBugId(null)} />}
    </div>
  );
}