'use client';

import React, { useCallback, useEffect, useRef, useState } from 'react';
import {
  AlertCircle,
  Check,
  Download,
  FileText,
  Loader2,
  Puzzle,
  RefreshCw,
  Rocket,
  Send,
  ShieldCheck,
  Trash2,
  Upload,
  X,
  XCircle,
} from 'lucide-react';

import {
  approveSkillDraft,
  deleteSkill,
  disablePublishedSkill,
  downloadSkill,
  listSkillCandidates,
  listSkillDrafts,
  listSkills,
  migrateSkills,
  publishSkillDraft,
  regenerateSkillDraft,
  rejectSkillDraft,
  rollbackPublishedSkill,
  submitSkillDraft,
  synthesizeSkillDraft,
  uploadSkill,
} from '@/lib/api';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import type { Skill, SkillDraft, SkillLearningCandidate } from '@/types';
import { pickAppText } from '@/lib/i18n/core';
import { useAppI18n } from '@/lib/i18n/provider';

const TERMINAL_DRAFT_STATUSES = new Set(['rejected', 'published', 'disabled', 'archived']);
const REJECTABLE_DRAFT_STATUSES = new Set(['draft', 'in_review', 'approved']);

export default function SkillsPage() {
  const { locale } = useAppI18n();
  const t = (zh: string, en: string) => pickAppText(locale, zh, en);
  const [skills, setSkills] = useState<Skill[]>([]);
  const [candidates, setCandidates] = useState<SkillLearningCandidate[]>([]);
  const [drafts, setDrafts] = useState<SkillDraft[]>([]);
  const [loading, setLoading] = useState(true);
  const [actionId, setActionId] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [showUpload, setShowUpload] = useState(false);
  const [ignoredCandidates, setIgnoredCandidates] = useState<Set<string>>(new Set());

  const load = useCallback(async () => {
    setLoading(true);
    setError(null);
    try {
      const [skillData, candidateData, draftData] = await Promise.all([
        listSkills(),
        listSkillCandidates().catch(() => []),
        listSkillDrafts().catch(() => []),
      ]);
      setSkills(Array.isArray(skillData) ? skillData : []);
      setCandidates(Array.isArray(candidateData) ? candidateData : []);
      setDrafts(Array.isArray(draftData) ? draftData : []);
    } catch (err: any) {
      setError(err.message || pickAppText(locale, '加载技能失败', 'Failed to load skills'));
    } finally {
      setLoading(false);
    }
  }, [locale]);

  useEffect(() => {
    void load();
  }, [load]);

  const runAction = async (id: string, action: () => Promise<unknown>) => {
    setActionId(id);
    setError(null);
    try {
      await action();
      await load();
    } catch (err: any) {
      setError(err.message || t('操作失败', 'Action failed'));
    } finally {
      setActionId(null);
    }
  };

  const hiddenCandidateStatuses = new Set(['rejected', 'superseded', 'published']);
  const visibleCandidates = candidates.filter(
    (candidate) => !ignoredCandidates.has(candidate.candidate_id) && !hiddenCandidateStatuses.has(candidate.status)
  );
  const visibleDrafts = drafts.filter((draft) => !TERMINAL_DRAFT_STATUSES.has(draft.status));

  if (loading) {
    return (
      <div className="flex items-center justify-center py-20">
        <Loader2 className="w-6 h-6 animate-spin text-muted-foreground" />
      </div>
    );
  }

  return (
    <div className="mx-auto max-w-6xl space-y-6 p-6">
      <div className="flex flex-wrap items-center justify-between gap-3">
        <h1 className="flex items-center gap-2 text-2xl font-bold">
          <Puzzle className="w-6 h-6" />
          {t('技能', 'Skills')}
        </h1>
        <div className="flex items-center gap-2">
          <Button onClick={() => void load()} variant="outline" size="sm">
            <RefreshCw className="mr-2 h-4 w-4" />
            {t('刷新', 'Refresh')}
          </Button>
          <Button onClick={() => setShowUpload(true)} size="sm">
            <Upload className="mr-2 h-4 w-4" />
            {t('上传技能', 'Upload skill')}
          </Button>
          <Button
            onClick={() => void runAction('migrate-skills', () => migrateSkills())}
            variant="outline"
            size="sm"
            disabled={Boolean(actionId)}
          >
            {actionId === 'migrate-skills' ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <Rocket className="mr-2 h-4 w-4" />}
            {t('迁移旧技能', 'Migrate legacy skills')}
          </Button>
        </div>
      </div>

      {error && (
        <Card className="border-destructive">
          <CardContent className="pt-6">
            <div className="flex items-center gap-2 text-sm text-destructive">
              <AlertCircle className="h-4 w-4" />
              {error}
            </div>
          </CardContent>
        </Card>
      )}

      {showUpload && (
        <UploadSkillForm
          onDone={() => {
            setShowUpload(false);
            void load();
          }}
          onCancel={() => setShowUpload(false)}
          onError={(msg) => setError(msg)}
        />
      )}

      <Tabs defaultValue="published" className="space-y-4">
        <TabsList>
          <TabsTrigger value="published">{t('已发布', 'Published')}</TabsTrigger>
          <TabsTrigger value="candidates">{t('候选', 'Candidates')}</TabsTrigger>
          <TabsTrigger value="drafts">{t('草稿评审', 'Draft review')}</TabsTrigger>
        </TabsList>

        <TabsContent value="published">
          <PublishedSkillsTable
            skills={skills}
            onDownload={(name) => downloadSkill(name).catch((err) => setError(err.message))}
            onDelete={(name) => void runAction(`delete:${name}`, () => deleteSkill(name))}
            onDisable={(name) =>
              runAction(`disable:${name}`, () => disablePublishedSkill(name, t('人工禁用', 'Manual disable')))
            }
            onRollback={(name) => {
              const target = window.prompt(t('回滚到版本，例如 v0001', 'Rollback target version, for example v0001'));
              if (target) {
                void runAction(`rollback:${name}`, () =>
                  rollbackPublishedSkill(name, target, t('人工回滚', 'Manual rollback'))
                );
              }
            }}
          />
        </TabsContent>

        <TabsContent value="candidates">
          <Card>
            <CardHeader>
              <CardTitle className="text-base">{t('学习候选', 'Learning candidates')}</CardTitle>
            </CardHeader>
            <CardContent>
              {visibleCandidates.length === 0 ? (
                <EmptyState icon={<FileText className="h-8 w-8" />} text={t('暂无学习候选', 'No learning candidates yet')} />
              ) : (
                <div className="space-y-3">
                  {visibleCandidates.map((candidate) => (
                    <div key={candidate.candidate_id} className="rounded-lg border border-border p-4">
                      <div className="flex flex-wrap items-start justify-between gap-3">
                        <div className="min-w-0">
                          <div className="flex flex-wrap items-center gap-2">
	                            <Badge variant="outline">{candidate.kind}</Badge>
	                            <Badge variant="secondary">{candidate.status}</Badge>
	                            <Badge variant={candidate.risk_level === 'critical' || candidate.risk_level === 'high' ? 'destructive' : 'outline'}>
	                              {candidate.risk_level || 'medium'}
	                            </Badge>
	                            <span className="font-mono text-xs text-muted-foreground">{candidate.candidate_id}</span>
	                          </div>
	                          <p className="mt-2 text-sm text-foreground">{candidate.reason}</p>
	                          {candidate.evidence_summary && (
	                            <p className="mt-1 text-xs text-muted-foreground">{candidate.evidence_summary}</p>
	                          )}
	                          <p className="mt-1 text-xs text-muted-foreground">
	                            {t('来源 runs', 'Source runs')}: {candidate.source_run_ids.join(', ') || '-'}
	                          </p>
                          {candidate.related_skill_names.length > 0 && (
                            <p className="mt-1 text-xs text-muted-foreground">
                              {t('关联技能', 'Related skills')}: {candidate.related_skill_names.join(', ')}
                            </p>
	                          )}
	                          {candidate.last_error && (
	                            <p className="mt-1 text-xs text-destructive">{candidate.last_error}</p>
	                          )}
	                        </div>
	                        <div className="flex flex-wrap gap-2">
                            <Button
                              size="sm"
                              variant="outline"
                              disabled={Boolean(actionId)}
                              onClick={() => setIgnoredCandidates((prev) => new Set(prev).add(candidate.candidate_id))}
                            >
                              {t('忽略', 'Ignore')}
                            </Button>
	                          <Button
	                            size="sm"
	                            disabled={Boolean(actionId)}
	                            onClick={() =>
	                              void runAction(`draft:${candidate.candidate_id}`, () =>
	                                synthesizeSkillDraft(candidate.candidate_id)
	                              )
	                            }
	                          >
	                            {actionId === `draft:${candidate.candidate_id}` ? (
	                              <Loader2 className="mr-2 h-4 w-4 animate-spin" />
	                            ) : (
	                              <FileText className="mr-2 h-4 w-4" />
	                            )}
	                            {t('生成草稿', 'Synthesize draft')}
	                          </Button>
	                          {candidate.draft_id && (
	                            <Button
	                              size="sm"
	                              variant="outline"
	                              disabled={Boolean(actionId)}
	                              onClick={() =>
	                                void runAction(`regen:${candidate.candidate_id}`, () =>
	                                  regenerateSkillDraft(candidate.candidate_id)
	                                )
	                              }
	                            >
	                              <RefreshCw className="mr-2 h-4 w-4" />
	                              {t('重新生成', 'Regenerate')}
	                            </Button>
	                          )}
	                        </div>
	                      </div>
                    </div>
                  ))}
                </div>
              )}
            </CardContent>
          </Card>
        </TabsContent>

        <TabsContent value="drafts">
          <Card>
            <CardHeader>
              <CardTitle className="text-base">{t('草稿、评审与发布', 'Drafts, review, and publish')}</CardTitle>
            </CardHeader>
            <CardContent>
              {visibleDrafts.length === 0 ? (
                <EmptyState icon={<FileText className="h-8 w-8" />} text={t('暂无草稿', 'No drafts yet')} />
              ) : (
                <div className="space-y-4">
                  {visibleDrafts.map((draft) => (
                    <DraftCard
                      key={`${draft.skill_name}:${draft.draft_id}`}
                      draft={draft}
                      actionId={actionId}
                      onSubmit={() =>
                        runAction(`submit:${draft.draft_id}`, () =>
                          submitSkillDraft(draft.skill_name, draft.draft_id)
                        )
                      }
                      onApprove={() =>
                        runAction(`approve:${draft.draft_id}`, () =>
                          approveSkillDraft(draft.skill_name, draft.draft_id)
                        )
                      }
                      onReject={() =>
                        runAction(`reject:${draft.draft_id}`, () =>
                          rejectSkillDraft(draft.skill_name, draft.draft_id)
                        )
                      }
                      onPublish={(confirmHighRisk) =>
                        runAction(`publish:${draft.draft_id}`, () =>
                          publishSkillDraft(draft.skill_name, draft.draft_id, '', confirmHighRisk)
                        )
                      }
                    />
                  ))}
                </div>
              )}
            </CardContent>
          </Card>
        </TabsContent>
      </Tabs>
    </div>
  );
}

function PublishedSkillsTable({
  skills,
  onDownload,
  onDelete,
  onDisable,
  onRollback,
}: {
  skills: Skill[];
  onDownload: (name: string) => void;
  onDelete: (name: string) => void;
  onDisable: (name: string) => void;
  onRollback: (name: string) => void;
}) {
  const { locale } = useAppI18n();
  const t = (zh: string, en: string) => pickAppText(locale, zh, en);
  return (
    <Card>
      <CardContent className="p-0">
        {skills.length === 0 ? (
          <EmptyState icon={<Puzzle className="h-8 w-8" />} text={t('暂无技能', 'No skills yet')} />
        ) : (
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead>{t('名称', 'Name')}</TableHead>
                <TableHead>{t('描述', 'Description')}</TableHead>
                <TableHead>{t('来源', 'Source')}</TableHead>
                <TableHead>{t('状态', 'Status')}</TableHead>
                <TableHead className="w-24">{t('操作', 'Actions')}</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {skills.map((skill) => (
                <TableRow key={`${skill.source}:${skill.name}`}>
                  <TableCell className="font-medium">{skill.name}</TableCell>
                  <TableCell>
                    <span className="block max-w-[360px] truncate text-sm text-muted-foreground">
                      {skill.description}
                    </span>
                  </TableCell>
                  <TableCell>
                    <Badge variant={skill.source === 'builtin' ? 'secondary' : 'default'} className="text-xs">
                      {skill.source === 'builtin' ? t('内置', 'Built in') : t('工作区', 'Workspace')}
                    </Badge>
                  </TableCell>
                  <TableCell>
                    <Badge variant={skill.available ? 'default' : 'outline'} className="text-xs">
                      {skill.available ? t('可用', 'Available') : t('不可用', 'Unavailable')}
                    </Badge>
                  </TableCell>
                  <TableCell>
                    <div className="flex items-center gap-1">
                      <Button variant="ghost" size="icon" className="h-7 w-7" onClick={() => onDownload(skill.name)}>
                        <Download className="h-3.5 w-3.5" />
                      </Button>
	                      {skill.source === 'workspace' && (
	                        <>
	                          <Button variant="ghost" size="icon" className="h-7 w-7" onClick={() => onRollback(skill.name)}>
	                            <RefreshCw className="h-3.5 w-3.5" />
	                          </Button>
	                          <Button variant="ghost" size="icon" className="h-7 w-7" onClick={() => onDisable(skill.name)}>
	                            <ShieldCheck className="h-3.5 w-3.5" />
	                          </Button>
	                          <Button
	                            variant="ghost"
	                            size="icon"
	                            className="h-7 w-7 text-destructive hover:text-destructive"
	                            onClick={() => onDelete(skill.name)}
	                          >
	                            <Trash2 className="h-3.5 w-3.5" />
	                          </Button>
	                        </>
	                      )}
                    </div>
                  </TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        )}
      </CardContent>
    </Card>
  );
}

function DraftCard({
  draft,
  actionId,
  onSubmit,
  onApprove,
  onReject,
  onPublish,
}: {
  draft: SkillDraft;
  actionId: string | null;
  onSubmit: () => Promise<unknown>;
  onApprove: () => Promise<unknown>;
  onReject: () => Promise<unknown>;
  onPublish: (confirmHighRisk: boolean) => Promise<unknown>;
}) {
  const { locale } = useAppI18n();
  const t = (zh: string, en: string) => pickAppText(locale, zh, en);
  const busy = Boolean(actionId);
  const safety = draft.safety_report;
  const evalReport = draft.eval_report;
  const publishBlocked =
    draft.status !== 'approved'
    || !safety
    || safety.risk_level === 'critical'
    || (evalReport?.status !== 'skipped_provider_unavailable' && evalReport?.passed === false);
  const isHighRisk = safety?.risk_level === 'high';
  const highRiskReason = [
    ...(safety?.blocked_reasons ?? []),
    ...(safety?.issues ?? []),
    safety?.suggested_fix,
  ].filter(Boolean).join('\n');
  const safetyBlocksReview = Boolean(safety && (!safety.passed || safety.risk_level === 'critical'));
  const submitBlocked = draft.status !== 'draft' || safetyBlocksReview;
  const approveBlocked = draft.status !== 'in_review' || safetyBlocksReview;
  const rejectBlocked = !REJECTABLE_DRAFT_STATUSES.has(draft.status);
  const handlePublish = () => {
    if (isHighRisk) {
      const confirmed = window.confirm(
        t('该草稿被标记为高风险。确认发布？', 'This draft is marked high risk. Publish anyway?')
      );
      if (!confirmed) return;
    }
    void onPublish(isHighRisk);
  };
  return (
    <div className="rounded-lg border border-border p-4">
      <div className="flex flex-wrap items-start justify-between gap-3">
        <div className="min-w-0">
          <div className="flex flex-wrap items-center gap-2">
	            <Badge variant="outline">{draft.proposal_kind}</Badge>
	            <Badge variant="secondary">{draft.status}</Badge>
	            {safety && (
	              <Badge variant={safety.risk_level === 'critical' || safety.risk_level === 'high' ? 'destructive' : 'outline'}>
	                {safety.risk_level}
	              </Badge>
	            )}
	            {evalReport && (
	              <Badge variant={evalReport.passed ? 'outline' : 'destructive'}>
	                {evalReport.status === 'skipped_provider_unavailable' ? t('未评估', 'Eval skipped') : evalReport.passed ? t('评估通过', 'Eval passed') : t('评估失败', 'Eval failed')}
	              </Badge>
	            )}
	            <span className="font-mono text-xs text-muted-foreground">{draft.skill_name}/{draft.draft_id}</span>
          </div>
          <p className="mt-2 text-sm">{draft.reason || t('无说明', 'No notes')}</p>
          <p className="mt-1 text-xs text-muted-foreground">
            {t('base', 'base')}: {draft.base_version || '-'}
          </p>
          {isHighRisk && (
            <div className="mt-3 rounded-md border border-destructive/30 bg-destructive/5 p-3 text-xs text-destructive">
              <div className="font-medium">{t('高风险理由来自 safety report', 'High-risk reason from safety report')}</div>
              <pre className="mt-2 whitespace-pre-wrap font-sans">{highRiskReason || t('未提供具体理由', 'No concrete reason provided')}</pre>
            </div>
          )}
        </div>
        <div className="flex flex-wrap gap-2">
          <Button variant="outline" size="sm" disabled={busy || submitBlocked} onClick={() => void onSubmit()}>
            <Send className="mr-2 h-4 w-4" />
            {t('送审', 'Submit')}
          </Button>
          <Button variant="outline" size="sm" disabled={busy || approveBlocked} onClick={() => void onApprove()}>
            <Check className="mr-2 h-4 w-4" />
            {t('批准', 'Approve')}
          </Button>
          <Button variant="outline" size="sm" disabled={busy || rejectBlocked} onClick={() => void onReject()}>
            <XCircle className="mr-2 h-4 w-4" />
            {t('拒绝', 'Reject')}
          </Button>
		          <Button size="sm" disabled={busy || publishBlocked} onClick={handlePublish}>
		            <Rocket className="mr-2 h-4 w-4" />
		            {t('发布', 'Publish')}
		          </Button>
        </div>
      </div>
	      <div className="mt-3 grid gap-3 md:grid-cols-2">
        <div className="rounded-md border border-border bg-muted/30 p-3">
          <div className="mb-2 text-xs font-medium text-muted-foreground">{t('当前版本', 'Current version')}</div>
          <pre className="max-h-52 overflow-auto whitespace-pre-wrap text-xs">
            {draft.base_version ? `${t('基线版本', 'Base version')}: ${draft.base_version}` : t('无基线版本，视为新增技能', 'No base version, treated as a new skill')}
          </pre>
        </div>
        <div className="rounded-md border border-border bg-muted/30 p-3">
          <div className="mb-2 text-xs font-medium text-muted-foreground">{t('草稿变更', 'Draft changes')}</div>
          <pre className="max-h-52 overflow-auto whitespace-pre-wrap text-xs">
            {JSON.stringify(draft.proposed_frontmatter, null, 2)}
            {'\n\n---\n\n'}
            {draft.proposed_content}
          </pre>
        </div>
	      </div>
	      <div className="mt-3 grid gap-3 md:grid-cols-2">
	        <ReportBlock
	          title={t('安全报告', 'Safety report')}
	          empty={t('暂无安全报告', 'No safety report')}
	          payload={safety}
	        />
	        <ReportBlock
	          title={t('评估报告', 'Eval report')}
	          empty={t('暂无评估报告', 'No eval report')}
	          payload={evalReport}
	        />
	      </div>
	    </div>
	  );
}

function ReportBlock({ title, empty, payload }: { title: string; empty: string; payload: unknown }) {
  return (
    <div className="rounded-md border border-border bg-muted/30 p-3">
      <div className="mb-2 text-xs font-medium text-muted-foreground">{title}</div>
      {payload ? (
        <pre className="max-h-48 overflow-auto whitespace-pre-wrap text-xs">{JSON.stringify(payload, null, 2)}</pre>
      ) : (
        <p className="text-xs text-muted-foreground">{empty}</p>
      )}
    </div>
  );
}

function EmptyState({ icon, text }: { icon: React.ReactNode; text: string }) {
  return (
    <div className="py-12 text-center text-muted-foreground">
      <div className="mx-auto mb-3 flex justify-center opacity-40">{icon}</div>
      <p className="text-sm font-medium">{text}</p>
    </div>
  );
}

function UploadSkillForm({
  onDone,
  onCancel,
  onError,
}: {
  onDone: () => void;
  onCancel: () => void;
  onError: (msg: string) => void;
}) {
  const { locale } = useAppI18n();
  const [uploading, setUploading] = useState(false);
  const fileRef = useRef<HTMLInputElement>(null);

  const handleSubmit = async (event: React.FormEvent) => {
    event.preventDefault();
    const file = fileRef.current?.files?.[0];
    if (!file) return;
    setUploading(true);
    try {
      await uploadSkill(file);
      onDone();
    } catch (err: any) {
      onError(err.message || pickAppText(locale, '上传失败', 'Upload failed'));
    } finally {
      setUploading(false);
    }
  };

  return (
    <Card>
      <CardHeader className="pb-4">
        <div className="flex items-center justify-between">
          <CardTitle className="text-base">{pickAppText(locale, '上传技能', 'Upload skill')}</CardTitle>
          <Button variant="ghost" size="icon" className="h-7 w-7" onClick={onCancel}>
            <X className="h-4 w-4" />
          </Button>
        </div>
      </CardHeader>
      <CardContent>
        <form onSubmit={handleSubmit} className="space-y-4">
          <div className="space-y-2">
            <label className="text-sm font-medium" htmlFor="skill-zip">
              {pickAppText(locale, '技能压缩包', 'Skill archive')}
            </label>
            <input
              id="skill-zip"
              ref={fileRef}
              type="file"
              accept=".zip"
              className="block w-full cursor-pointer text-sm text-muted-foreground file:mr-4 file:rounded-md file:border-0 file:bg-primary file:px-4 file:py-2 file:text-sm file:font-medium file:text-primary-foreground hover:file:bg-primary/90"
            />
            <p className="text-xs text-muted-foreground">
              {pickAppText(locale, '上传后进入草稿评审，并自动运行 safety 和 eval。', 'After upload, the skill enters draft review and runs safety and eval automatically.')}
            </p>
          </div>
          <div className="flex justify-end gap-2">
            <Button type="button" variant="outline" onClick={onCancel}>
              {pickAppText(locale, '取消', 'Cancel')}
            </Button>
            <Button type="submit" disabled={uploading}>
              {uploading ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <Upload className="mr-2 h-4 w-4" />}
              {pickAppText(locale, '上传', 'Upload')}
            </Button>
          </div>
        </form>
      </CardContent>
    </Card>
  );
}