'use client';

import { useEffect, useMemo, useState } from 'react';
import { useParams, useRouter } from 'next/navigation';
import { ChevronLeft, Package, Calendar, Clock, Users, Tag, ChevronDown } from 'lucide-react';
import { useProductStore } from '@/stores/useProductStore';
import { useRequirementStore } from '@/stores/useRequirementStore';
import { useOvertimeStore } from '@/stores/useOvertimeStore';
import { useVersionPlanStore } from '@/stores/useVersionPlanStore';
import { useDevTaskStore } from '@/stores/useDevTaskStore';
import { useTestCaseStore } from '@/stores/useTestCaseStore';
import { getProjectDetail, VersionWithContext } from '@/lib/derive';
import { Stage, Role, STAGES, ROLES, STAGE_INDEX, ROLE_LABEL } from '@/lib/stage';
import { VersionStatus, VERSION_STATUS_LABEL, VERSION_STATUS_BG } from '@/lib/version-status';
import { STATUS_PROGRESS } from '@/lib/dev-task';
import { CapsuleStages } from '@/components/version/CapsuleStages';
import { MemberChips } from '@/components/version/MemberChips';

/* ─── StatCard ─── */
function StatCard({ value, label }: { value: number | string; label: string }) {
  return (
    <div className="rounded-xl border border-[var(--line)] bg-[var(--bg-card)] p-4">
      <div className="text-2xl font-bold text-[var(--ink)]">{value}</div>
      <div className="text-xs text-[var(--ink-muted)] mt-1">{label}</div>
    </div>
  );
}

/* ─── ProgressBar (for expanded released cards) ─── */
function ProgressBar({ role, percent, daysSpent }: { role: Role; percent: number; daysSpent: number }) {
  return (
    <div className="flex items-center gap-2">
      <span className="w-12 text-xs text-[var(--ink-soft)] shrink-0">{ROLE_LABEL[role]}</span>
      <div className="flex-1 h-2 rounded-full bg-zinc-100 overflow-hidden">
        <div className="h-full rounded-full bg-blue-500 transition-all" style={{ width: `${percent}%` }} />
      </div>
      <span className="text-xs text-[var(--ink-muted)] w-8 text-right">{percent}%</span>
      <span className="text-xs text-[var(--ink-muted)] w-10 text-right">
        {daysSpent === 0 ? '-' : `${daysSpent}天`}
      </span>
    </div>
  );
}

/* ─── VersionCard ─── */
function VersionCard({ version, progress, onNavigate }: { version: VersionWithContext; progress: number; onNavigate: (id: string) => void }) {
  const [expanded, setExpanded] = useState(false);

  // Calculate actual elapsed days from dates instead of old progress data
  const totalDays = useMemo(() => {
    if (!version.startDate) return 0;
    const start = new Date(version.startDate);
    start.setHours(0, 0, 0, 0);
    const end = version.status === 'released' && version.releaseDate
      ? new Date(version.releaseDate)
      : new Date();
    end.setHours(0, 0, 0, 0);
    return Math.max(0, Math.floor((end.getTime() - start.getTime()) / (1000 * 60 * 60 * 24)));
  }, [version.startDate, version.releaseDate, version.status]);

  const displayStatus = VERSION_STATUS_LABEL[version.status] ?? '开发中';
  const displayBg = VERSION_STATUS_BG[version.status] ?? 'bg-blue-500/10 text-blue-600';

  if (version.status === 'planned') {
    return (
      <div className="rounded-xl border border-dashed border-[var(--line)] px-4 py-3">
        <div className="flex items-center gap-2">
          <span onClick={() => onNavigate(version.id)} className="text-sm font-medium text-[var(--ink)] cursor-pointer hover:text-[var(--accent)]">{version.name}</span>
          <span className={`text-[11px] px-2 py-0.5 rounded-full ${displayBg}`}>{displayStatus}</span>
          <span className="text-[11px] text-[var(--ink-muted)]">暂无详情</span>
        </div>
      </div>
    );
  }

  if (version.status === 'released') {
    return (
      <div className="rounded-xl border border-[var(--line)] bg-[var(--bg-card)] overflow-hidden">
        <button
          type="button"
          onClick={() => setExpanded(!expanded)}
          className="w-full flex items-center gap-3 px-4 py-3 text-left hover:bg-[var(--bg-hover)] transition-colors"
        >
          <span onClick={(e) => { e.stopPropagation(); onNavigate(version.id); }} className="text-sm font-medium text-[var(--ink)] cursor-pointer hover:text-[var(--accent)]">{version.name}</span>
          <span className={`text-[11px] px-2 py-0.5 rounded-full ${displayBg}`}>{displayStatus}</span>
          <span className="flex-1 text-[11px] text-[var(--ink-muted)] flex items-center gap-1">
            <Calendar className="h-3 w-3" />
            {version.startDate ?? '-'} → {version.releaseDate ?? '-'}
            <span className="ml-1">共 {totalDays} 天</span>
          </span>
          <ChevronDown className={`h-3.5 w-3.5 text-[var(--ink-muted)] transition-transform ${expanded ? 'rotate-180' : ''}`} />
        </button>
        {expanded && (
          <div className="px-4 pb-4 pt-2 border-t border-[var(--line-soft)] space-y-3">
            <CapsuleStages />
            <MemberChips members={version.members ?? []} />
          </div>
        )}
      </div>
    );
  }

  return (
    <div className="rounded-xl border border-[var(--line)] bg-[var(--bg-card)] p-4 shadow-sm">
      <div className="flex items-center gap-2 mb-3">
        <span onClick={() => onNavigate(version.id)} className="text-sm font-medium text-[var(--ink)] cursor-pointer hover:text-[var(--accent)]">{version.name}</span>
        <span className={`text-[11px] px-2 py-0.5 rounded-full ${displayBg}`}>{displayStatus}</span>
        <div className="flex-1 flex items-center gap-2 ml-2">
          <div className="flex-1 h-1.5 rounded-full bg-zinc-100 max-w-[160px]">
            <div className="h-1.5 rounded-full bg-blue-500 transition-all" style={{ width: `${progress}%` }} />
          </div>
          <span className="text-[11px] tabular-nums text-[var(--ink-muted)]">{progress}%</span>
        </div>
      </div>
      <div className="mb-3"><CapsuleStages /></div>
      <div className="flex items-center justify-between text-[11px] text-[var(--ink-muted)] mb-3 pb-3 border-b border-[var(--line-soft)]">
        <span className="flex items-center gap-1">
          <Calendar className="h-3 w-3" />
          {version.startDate ?? '-'} → 预计 {version.expectedReleaseDate ?? '-'}
        </span>
        <span className="flex items-center gap-1">
          <Clock className="h-3 w-3" />已耗时 {totalDays} 天
        </span>
      </div>
      <MemberChips members={version.members ?? []} />
    </div>
  );
}

/* ─── TeamSection (compact, overflow with tooltip) ─── */
function TeamSection({ teamByRole }: { teamByRole: Record<string, Record<string, number>> }) {
  const MAX_VISIBLE = 4;
  return (
    <section>
      <div className="flex items-center gap-2 mb-3">
        <Users className="h-4 w-4 text-[var(--ink-soft)]" />
        <h2 className="text-sm font-semibold text-[var(--ink)]">项目人员</h2>
      </div>
      <div className="rounded-xl border border-[var(--line)] bg-[var(--bg-card)] px-4 py-3">
        <div className="flex flex-wrap items-center gap-x-5 gap-y-2">
          {ROLES.map((role) => {
            const peopleMap = teamByRole[role.key] || {};
            const people = Object.entries(peopleMap).sort((a, b) => (b[1] as number) - (a[1] as number));
            if (people.length === 0) return null;
            const visible = people.slice(0, MAX_VISIBLE);
            const hidden = people.slice(MAX_VISIBLE);
            return (
              <div key={role.key} className="flex items-center gap-1.5">
                <span className="text-[11px] font-medium text-[var(--ink-muted)]">{role.label}</span>
                <div className="flex items-center gap-1">
                  {visible.map(([name, count]) => (
                    <span key={name} className="inline-flex items-center h-5 px-1.5 rounded bg-[var(--bg-subtle)] text-[11px] text-[var(--ink-soft)]">
                      {name}<span className="text-[var(--ink-muted)] ml-0.5">{'×'}{count as number}</span>
                    </span>
                  ))}
                  {hidden.length > 0 && (
                    <span className="relative group">
                      <span className="inline-flex items-center h-5 px-1.5 rounded bg-[var(--bg-subtle)] text-[11px] text-[var(--ink-muted)] cursor-default">
                        +{hidden.length}
                      </span>
                      <span className="absolute bottom-full left-1/2 -translate-x-1/2 mb-1.5 hidden group-hover:flex flex-col items-center z-10">
                        <span className="whitespace-nowrap rounded-lg bg-zinc-800 px-2.5 py-1.5 text-[11px] text-white shadow-lg">
                          {hidden.map(([n, c]) => `${n}(×${c})`).join(', ')}
                        </span>
                        <span className="h-1.5 w-1.5 rotate-45 bg-zinc-800 -mt-1" />
                      </span>
                    </span>
                  )}
                </div>
              </div>
            );
          })}
        </div>
      </div>
    </section>
  );
}

/* ─── Status Filter ─── */
const FILTER_OPTIONS: { key: string; label: string }[] = [
  { key: 'all', label: '全部' },
  { key: 'requirement', label: '调研' },
  { key: 'product_design', label: '产品设计' },
  { key: 'ui_design', label: 'UI设计' },
  { key: 'dev', label: '开发' },
  { key: 'testing', label: '测试' },
  { key: 'released', label: '已发布' },
  { key: 'planned', label: '规划中' },
];

/* ─── Main Page ─── */
export default function ProjectDetailPage() {
  const params = useParams();
  const router = useRouter();
  const projectId = params.id as string;
  const { overview, fetchOverview } = useProductStore();
  const { requirements, fetchRequirements } = useRequirementStore();
  const { records, fetchRecords } = useOvertimeStore();
  const { plans, fetchPlans } = useVersionPlanStore();
  const { tasks: devTasks, fetchTasks: fetchDevTasks } = useDevTaskStore();
  const { testCases, fetchTestCases } = useTestCaseStore();
  const [statusFilter, setStatusFilter] = useState<string>('all');

  useEffect(() => { fetchOverview(); }, [fetchOverview]);
  useEffect(() => { fetchRequirements(); }, [fetchRequirements]);
  useEffect(() => { fetchRecords(); }, [fetchRecords]);
  useEffect(() => { fetchPlans(); }, [fetchPlans]);
  useEffect(() => { fetchDevTasks(); }, [fetchDevTasks]);
  useEffect(() => { fetchTestCases(); }, [fetchTestCases]);

  const project = useMemo(() => getProjectDetail(overview, projectId), [overview, projectId]);

  const sortedVersions = useMemo(() => {
    if (!project) return [];
    let list = [...project.versions];
    if (statusFilter !== 'all') {
      if (statusFilter === 'planned') {
        list = list.filter((v) => v.status === 'planned');
      } else if (statusFilter === 'released') {
        list = list.filter((v) => v.status === 'released');
      } else {
        list = list.filter((v) => v.status === 'developing' && v.currentStage === statusFilter);
      }
    }
    return list.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime());
  }, [project, statusFilter]);

  // Compute actual overall progress per version
  const versionProgressMap = useMemo(() => {
    if (!project) return {} as Record<string, number>;
    const map: Record<string, number> = {};
    for (const v of project.versions) {
      const vPlans = plans.filter((p) => p.versionId === v.id);
      const vReqs = requirements.filter((r) => r.versionId === v.id);
      const vReqIds = new Set(vReqs.map((r) => r.id));
      const vDevTasks = devTasks.filter((t) => vReqIds.has(t.requirementId));
      const vTestCases = testCases.filter((c) => c.versionId === v.id);

      const segments: number[] = [];

      const researchPlans = vPlans.filter((p) => p.type === 'research');
      if (researchPlans.length > 0) {
        const totals = researchPlans.reduce((acc, p) => {
          const tasks = p.tasks || [];
          acc.total += tasks.length;
          acc.done += tasks.filter((t) => t.status === 'completed').length;
          return acc;
        }, { total: 0, done: 0 });
        segments.push(totals.total > 0 ? (totals.done / totals.total) * 100 : 0);
      }

      const productPlans = vPlans.filter((p) => p.type === 'product');
      if (productPlans.length > 0) {
        const totals = productPlans.reduce((acc, p) => {
          const linked = p.linkedRequirementIds || [];
          const completed = p.completedRequirementIds || [];
          acc.total += linked.length;
          acc.done += completed.filter((id) => linked.includes(id)).length;
          return acc;
        }, { total: 0, done: 0 });
        segments.push(totals.total > 0 ? (totals.done / totals.total) * 100 : 0);
      }

      const uiPlans = vPlans.filter((p) => p.type === 'ui');
      if (uiPlans.length > 0) {
        const totals = uiPlans.reduce((acc, p) => {
          const linked = p.linkedRequirementIds || [];
          const completed = p.completedRequirementIds || [];
          acc.total += linked.length;
          acc.done += completed.filter((id) => linked.includes(id)).length;
          return acc;
        }, { total: 0, done: 0 });
        segments.push(totals.total > 0 ? (totals.done / totals.total) * 100 : 0);
      }

      if (vDevTasks.length > 0) {
        const totalEstimate = vDevTasks.reduce((sum, t) => sum + t.estimateHours, 0);
        let devProgress: number;
        if (totalEstimate === 0) {
          devProgress = vDevTasks.reduce((sum, t) => sum + STATUS_PROGRESS[t.status], 0) / vDevTasks.length;
        } else {
          const weighted = vDevTasks.reduce((sum, t) => sum + t.estimateHours * STATUS_PROGRESS[t.status], 0);
          devProgress = weighted / totalEstimate;
        }
        segments.push(devProgress);
      }

      if (vTestCases.length > 0) {
        const executed = vTestCases.filter((c) => c.status === 'passed' || c.status === 'failed' || c.status === 'blocked').length;
        segments.push((executed / vTestCases.length) * 100);
      }

      map[v.id] = segments.length > 0 ? Math.round(segments.reduce((s, x) => s + x, 0) / segments.length) : 0;
    }
    return map;
  }, [project, plans, requirements, devTasks, testCases]);

  const stats = useMemo(() => {
    if (!project) return { total: 0, developing: 0, released: 0, totalDays: 0, reqCount: 0, overtimeHours: 0 };
    const total = project.versions.length;
    const developing = project.versions.filter((v) => v.status === 'developing').length;
    const released = project.versions.filter((v) => v.status === 'released').length;
    const totalDays = project.versions.reduce((sum, v) => {
      if (!v.startDate) return sum;
      const start = new Date(v.startDate);
      start.setHours(0, 0, 0, 0);
      const end = v.status === 'released' && v.releaseDate ? new Date(v.releaseDate) : new Date();
      end.setHours(0, 0, 0, 0);
      return sum + Math.max(0, Math.floor((end.getTime() - start.getTime()) / (1000 * 60 * 60 * 24)));
    }, 0);
    const reqCount = requirements.filter((r) => r.projectId === projectId).length;
    const overtimeHours = Math.round(records.filter((r) => r.projectId === projectId).reduce((sum, r) => sum + r.duration, 0) * 10) / 10;
    return { total, developing, released, totalDays, reqCount, overtimeHours };
  }, [project, requirements, records, projectId]);

  const teamByRole = useMemo(() => {
    if (!project) return {} as Record<string, Record<string, number>>;
    const map: Record<string, Record<string, number>> = {};
    ROLES.forEach((r) => (map[r.key] = {}));
    project.versions.forEach((v) => {
      (v.members ?? []).forEach((m) => {
        if (!map[m.role]) map[m.role] = {};
        map[m.role][m.name] = (map[m.role][m.name] || 0) + 1;
      });
    });
    return map;
  }, [project]);

  if (!project) {
    return (
      <div className="flex h-full flex-col items-center justify-center gap-3">
        <p className="text-sm text-[var(--ink-muted)]">项目不存在</p>
        <button onClick={() => router.push('/projects')} className="text-xs text-[var(--accent)] hover:underline">返回项目列表</button>
      </div>
    );
  }

  return (
    <div className="flex h-full flex-col">
      <header className="flex h-14 shrink-0 items-center justify-between border-b border-[var(--line)] bg-[var(--bg-card)] px-5">
        <div className="flex items-center">
          <button onClick={() => router.push('/projects')} className="flex items-center gap-1 rounded-md px-1.5 py-1 text-[12px] text-[var(--ink-muted)] hover:bg-[var(--bg-subtle)] hover:text-[var(--ink)]">
            <ChevronLeft className="h-3.5 w-3.5" strokeWidth={2} />项目
          </button>
          <span className="ml-2 text-[var(--ink-muted)]">/</span>
          <span className="ml-2 text-[15px] font-semibold text-[var(--ink)]">{project.name}</span>
        </div>
        <div className="flex items-center gap-1.5 rounded-full bg-[var(--bg-subtle)] px-2.5 py-1 text-xs text-[var(--ink-soft)]">
          <Package className="h-3 w-3" /><span>{project.productName}</span>
        </div>
      </header>

      <div className="flex-1 overflow-y-auto p-5 bg-[var(--bg)]">
        <div className="space-y-5">
          <div className="grid grid-cols-6 gap-4">
            <StatCard value={stats.total} label="总版本数" />
            <StatCard value={stats.developing} label="进行中" />
            <StatCard value={stats.released} label="已发布" />
            <StatCard value={stats.totalDays} label="总耗时(天)" />
            <StatCard value={stats.reqCount} label="需求数" />
            <StatCard value={stats.overtimeHours} label="加班(h)" />
          </div>

          <TeamSection teamByRole={teamByRole} />

          <section>
            <div className="flex items-center justify-between mb-3">
              <div className="flex items-center gap-2">
                <Tag className="h-4 w-4 text-[var(--ink-soft)]" />
                <h2 className="text-sm font-semibold text-[var(--ink)]">版本记录</h2>
              </div>
              <div className="flex items-center gap-0.5 rounded-lg bg-[var(--bg-subtle)] p-0.5">
                {FILTER_OPTIONS.map((opt) => (
                  <button
                    key={opt.key}
                    onClick={() => setStatusFilter(opt.key)}
                    className={`px-2.5 py-1 rounded-md text-[11px] font-medium transition-colors ${statusFilter === opt.key ? 'bg-[var(--bg-card)] text-[var(--ink)] shadow-sm' : 'text-[var(--ink-muted)] hover:text-[var(--ink-soft)]'}`}
                  >
                    {opt.label}
                  </button>
                ))}
              </div>
            </div>
            <div className="space-y-2.5">
              {sortedVersions.length === 0 ? (
                <div className="rounded-xl border border-dashed border-[var(--line)] p-6 text-center text-xs text-[var(--ink-muted)]">暂无版本</div>
              ) : (
                sortedVersions.map((v) => <VersionCard key={v.id} version={v} progress={versionProgressMap[v.id] ?? 0} onNavigate={(id) => router.push(`/versions/${id}`)} />)
              )}
            </div>
          </section>
        </div>
      </div>
    </div>
  );
}