import { useState } from "react";
import { useNavigate, useParams } from "react-router-dom";
import { useTranslation } from "react-i18next";
import { useForm } from "react-hook-form";
import { zodResolver } from "@hookform/resolvers/zod";
import { z } from "zod";
import { toast } from "sonner";
import {
  AlertCircle,
  ArrowLeft,
  ArrowRight,
  Ban,
  CheckCircle2,
  Globe,
  Loader2,
  PlayCircle,
  XCircle,
} from "lucide-react";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Select } from "@/components/ui/select";
import { Progress } from "@/components/ui/progress";
import { Badge, BadgeProps } from "@/components/ui/badge";
import { Skeleton } from "@/components/ui/skeleton";
import { useProject } from "@/hooks/useProjects";
import {
  useCancelCrawl,
  useCrawlJob,
  useStartSiteCrawl,
} from "@/hooks/useCrawl";
import { isCrawlTerminal } from "@/lib/api/crawl";

const startCrawlSchema = z.object({
  source_name: z.string().min(1, "소스를 선택하세요"),
  url: z.string().url("올바른 URL 형식이 아닙니다"),
  max_depth: z.number().int().min(0).max(10),
  max_pages: z.number().int().min(1).max(500),
  same_domain_only: z.boolean(),
  extraction_mode: z.enum(["rule_only", "llm_only", "hybrid", "compare"]),
  extractor_provider: z.enum(["lm_studio", "openai", "ollama"]),
  extractor_model: z.string().optional(),
  extractor_base_url: z.string().optional(),
  fallback_to_rules: z.boolean(),
});

type StartCrawlFormValues = z.infer<typeof startCrawlSchema>;

function statusBadgeVariant(status: string): BadgeProps["variant"] {
  switch (status) {
    case "completed":
      return "success";
    case "failed":
      return "destructive";
    case "canceled":
      return "secondary";
    case "cancel_requested":
      return "warning";
    case "running":
    case "pending":
      return "default";
    default:
      return "outline";
  }
}

function StatusBadge({ status }: { status: string }) {
  return <Badge variant={statusBadgeVariant(status)}>{status}</Badge>;
}

export default function CrawlPage() {
  const navigate = useNavigate();
  const { projectId } = useParams<{ projectId: string }>();
  const { t } = useTranslation();
  const projectName = projectId ?? "";

  const { data: project, isLoading, isError, error, refetch } = useProject(projectName);
  const [activeJobId, setActiveJobId] = useState<string | null>(null);
  const { data: job } = useCrawlJob(activeJobId);
  const startCrawl = useStartSiteCrawl();
  const cancelCrawl = useCancelCrawl();

  const {
    register,
    handleSubmit,
    setValue,
    watch,
    formState: { errors, isSubmitting },
  } = useForm<StartCrawlFormValues>({
    resolver: zodResolver(startCrawlSchema),
    defaultValues: {
      source_name: "",
      url: "",
      max_depth: 2,
      max_pages: 30,
      same_domain_only: true,
      extraction_mode: "hybrid",
      extractor_provider: "lm_studio",
      extractor_model: "",
      extractor_base_url: "http://localhost:1234/v1",
      fallback_to_rules: true,
    },
  });

  const onStart = async (values: StartCrawlFormValues) => {
    try {
      const usesLlm = values.extraction_mode !== "rule_only";
      const created = await startCrawl.mutateAsync({
        project_name: projectName,
        ...values,
        extractor_model: usesLlm ? values.extractor_model || null : null,
        extractor_base_url: usesLlm ? values.extractor_base_url || null : null,
      });
      setActiveJobId(created.job_id);
      toast.success(
        t("crawl.started", "크롤이 시작되었습니다 (job #{{id}})", {
          id: created.job_id,
        }),
      );
    } catch (e) {
      toast.error(
        t("crawl.startFailed", "시작 실패: {{msg}}", {
          msg: (e as Error).message,
        }),
      );
    }
  };

  const onCancel = async () => {
    if (!activeJobId) return;
    try {
      await cancelCrawl.mutateAsync(activeJobId);
      toast.info(t("crawl.cancelRequested", "취소 요청됨"));
    } catch (e) {
      toast.error(
        t("crawl.cancelFailed", "취소 실패: {{msg}}", {
          msg: (e as Error).message,
        }),
      );
    }
  };

  const sources = project?.sources ?? [];
  const sourceName = watch("source_name");
  const extractionMode = watch("extraction_mode");
  const usesLlm = extractionMode !== "rule_only";
  const selectedSource = sources.find((s) => s.name === sourceName);
  const progress = job?.progress;
  const visited = progress?.visited_count ?? 0;
  const queued = progress?.queued_count ?? 0;
  const analyzed = progress?.analyzed_count ?? 0;
  const errors_ = progress?.errors ?? [];
  const max_pages = watch("max_pages");
  const progressPct = job && max_pages
    ? Math.min(100, (visited / max_pages) * 100)
    : 0;
  const terminal = job ? isCrawlTerminal(job.status) : false;
  const running = job && !terminal;

  return (
    <div className="mx-auto max-w-6xl px-6 py-10">
      <div className="mb-6 flex items-center gap-3">
        <Button
          variant="ghost"
          size="icon"
          onClick={() => navigate(`/sources/${projectName}`)}
          aria-label={t("common.back", "이전")}
        >
          <ArrowLeft className="h-4 w-4" />
        </Button>
        <div className="flex-1">
          <h1 className="text-2xl font-bold tracking-tight">
            {t("crawl.title", "시드 크롤")}
          </h1>
          {project && (
            <p className="text-sm text-muted-foreground">
              {project.name}
              <span className="capitalize text-muted-foreground/70">
                {" "}
                · {project.domain}
              </span>
            </p>
          )}
        </div>
        {terminal && job?.status === "completed" && (
          <Button onClick={() => navigate(`/pipeline/${projectName}`)}>
            {t("crawl.review", "파이프라인 확인")}
            <ArrowRight className="h-4 w-4" />
          </Button>
        )}
      </div>

      {isError && (
        <Card className="mb-6 border-destructive">
          <CardContent className="flex items-center justify-between gap-3 py-4">
            <div className="flex items-center gap-2 text-sm text-destructive">
              <AlertCircle className="h-4 w-4" />
              <span>{(error as Error).message}</span>
            </div>
            <Button
              variant="outline"
              size="sm"
              type="button"
              onClick={() => refetch()}
            >
              {t("common.retry", "다시 시도")}
            </Button>
          </CardContent>
        </Card>
      )}

      <div className="grid gap-6 lg:grid-cols-[420px_1fr]">
        <Card>
          <CardHeader>
            <CardTitle>{t("crawl.formTitle", "크롤 설정")}</CardTitle>
            <CardDescription>
              {t(
                "crawl.formDesc",
                "시드 URL에서 시작해 링크를 따라가며 정보를 추출합니다",
              )}
            </CardDescription>
          </CardHeader>
          <CardContent>
            <form
              onSubmit={handleSubmit(onStart)}
              className="space-y-4"
              noValidate
            >
              <div className="space-y-1.5">
                <Label htmlFor="source_name">
                  {t("crawl.source", "참고 소스")}
                </Label>
                {isLoading ? (
                  <Skeleton className="h-10" />
                ) : (
                  <Select
                    id="source_name"
                    {...register("source_name")}
                    onChange={(e) => {
                      const nextSourceName = e.target.value;
                      const nextSource = sources.find(
                        (source) => source.name === nextSourceName,
                      );

                      setValue("source_name", nextSourceName, {
                        shouldValidate: true,
                        shouldDirty: true,
                      });
                      setValue("url", nextSource?.base_url ?? "", {
                        shouldValidate: Boolean(nextSource?.base_url),
                        shouldDirty: true,
                      });
                    }}
                  >
                    <option value="">
                      {t("crawl.pickSource", "소스를 선택하세요...")}
                    </option>
                    {sources.map((s) => (
                      <option key={s.id} value={s.name}>
                        {s.name} ({s.type})
                      </option>
                    ))}
                  </Select>
                )}
                {sources.length === 0 && !isLoading && (
                  <p className="text-xs text-muted-foreground">
                    {t(
                      "crawl.noSources",
                      "등록된 소스가 없습니다. 먼저 참고 소스를 추가하세요.",
                    )}{" "}
                    <button
                      type="button"
                      className="text-primary underline"
                      onClick={() => navigate(`/sources/${projectName}`)}
                    >
                      {t("crawl.addSource", "소스 추가")}
                    </button>
                  </p>
                )}
                {errors.source_name && (
                  <p className="text-xs text-destructive">
                    {errors.source_name.message}
                  </p>
                )}
              </div>

              <div className="space-y-1.5">
                <Label htmlFor="url">{t("crawl.seedUrl", "시드 URL")}</Label>
                <Input
                  id="url"
                  placeholder={
                    selectedSource?.base_url ?? "https://example.com/start"
                  }
                  {...register("url")}
                />
                {errors.url && (
                  <p className="text-xs text-destructive">
                    {errors.url.message}
                  </p>
                )}
              </div>

              <div className="grid grid-cols-2 gap-3">
                <div className="space-y-1.5">
                  <Label htmlFor="max_depth">
                    {t("crawl.maxDepth", "최대 깊이")}
                  </Label>
                  <Input
                    id="max_depth"
                    type="number"
                    min={0}
                    max={10}
                    {...register("max_depth", { valueAsNumber: true })}
                  />
                  {errors.max_depth && (
                    <p className="text-xs text-destructive">
                      {errors.max_depth.message}
                    </p>
                  )}
                </div>
                <div className="space-y-1.5">
                  <Label htmlFor="max_pages">
                    {t("crawl.maxPages", "최대 페이지")}
                  </Label>
                  <Input
                    id="max_pages"
                    type="number"
                    min={1}
                    max={500}
                    {...register("max_pages", { valueAsNumber: true })}
                  />
                  {errors.max_pages && (
                    <p className="text-xs text-destructive">
                      {errors.max_pages.message}
                    </p>
                  )}
                </div>
              </div>

              <label className="flex items-center gap-2 text-sm">
                <input
                  type="checkbox"
                  className="h-4 w-4 rounded border-input"
                  {...register("same_domain_only")}
                />
                <span>
                  {t("crawl.sameDomainOnly", "동일 도메인만 따라가기")}
                </span>
              </label>

              <div className="space-y-3 rounded-md border bg-background-subtle p-3">
                <div className="grid grid-cols-2 gap-3">
                  <div className="space-y-1.5">
                    <Label htmlFor="extraction_mode">Extraction mode</Label>
                    <Select id="extraction_mode" {...register("extraction_mode")}>
                      <option value="hybrid">Hybrid</option>
                      <option value="rule_only">Rule only</option>
                      <option value="llm_only">LLM only</option>
                      <option value="compare">Compare</option>
                    </Select>
                  </div>
                  <div className="space-y-1.5">
                    <Label htmlFor="extractor_provider">Provider</Label>
                    <Select
                      id="extractor_provider"
                      disabled={!usesLlm}
                      {...register("extractor_provider")}
                    >
                      <option value="lm_studio">LM Studio</option>
                      <option value="openai">OpenAI</option>
                      <option value="ollama">Ollama</option>
                    </Select>
                  </div>
                </div>
                {usesLlm && (
                  <>
                    <div className="space-y-1.5">
                      <Label htmlFor="extractor_model">Model</Label>
                      <Input
                        id="extractor_model"
                        placeholder="deepseek-r1-distill-qwen-7b"
                        {...register("extractor_model")}
                      />
                    </div>
                    <div className="space-y-1.5">
                      <Label htmlFor="extractor_base_url">Base URL</Label>
                      <Input
                        id="extractor_base_url"
                        placeholder="http://localhost:1234/v1"
                        {...register("extractor_base_url")}
                      />
                    </div>
                    <label className="flex items-center gap-2 text-sm">
                      <input
                        type="checkbox"
                        className="h-4 w-4 rounded border-input"
                        {...register("fallback_to_rules")}
                      />
                      <span>Fallback to rules</span>
                    </label>
                  </>
                )}
              </div>

              <Button
                type="submit"
                className="w-full"
                disabled={isSubmitting || startCrawl.isPending || Boolean(running)}
              >
                {startCrawl.isPending ? (
                  <Loader2 className="h-4 w-4 animate-spin" />
                ) : (
                  <PlayCircle className="h-4 w-4" />
                )}
                {t("crawl.start", "크롤 시작")}
              </Button>
            </form>
          </CardContent>
        </Card>

        <Card>
          <CardHeader>
            <div className="flex items-center justify-between">
              <div>
                <CardTitle>
                  {t("crawl.progressTitle", "진행 상태")}
                </CardTitle>
                {job && (
                  <CardDescription className="flex items-center gap-2">
                    <span>job #{job.job_id}</span>
                    <StatusBadge status={job.status} />
                  </CardDescription>
                )}
              </div>
              {running && (
                <Button
                  variant="outline"
                  size="sm"
                  onClick={onCancel}
                  disabled={cancelCrawl.isPending}
                >
                  <Ban className="h-4 w-4" />
                  {t("crawl.cancel", "취소")}
                </Button>
              )}
            </div>
          </CardHeader>
          <CardContent>
            {!job && (
              <div className="flex flex-col items-center gap-3 py-12 text-center text-muted-foreground">
                <Globe className="h-12 w-12 opacity-40" />
                <p>
                  {t(
                    "crawl.idleHint",
                    "왼쪽에서 시드 URL을 입력하고 시작하세요",
                  )}
                </p>
              </div>
            )}

            {job && (
              <div className="space-y-4">
                <div>
                  <div className="mb-1 flex items-center justify-between text-sm">
                    <span className="text-muted-foreground">
                      {t("crawl.visited", "방문")} {visited}
                      {" / "}
                      {max_pages}
                    </span>
                    <span className="text-muted-foreground">
                      {t("crawl.queued", "대기")} {queued} ·{" "}
                      {t("crawl.analyzed", "분석")} {analyzed}
                    </span>
                  </div>
                  <Progress value={progressPct} indeterminate={running && visited === 0} />
                </div>

                {job.url && (
                  <div className="rounded-md bg-secondary/30 px-3 py-2 text-xs">
                    <div className="text-muted-foreground">
                      {t("crawl.seedUrl", "시드 URL")}
                    </div>
                    <a
                      href={job.url}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="break-all text-foreground hover:underline"
                    >
                      {job.url}
                    </a>
                  </div>
                )}

                {progress?.latest_page && (
                  <div className="rounded-md border bg-background px-3 py-2 text-xs">
                    <div className="mb-1 text-muted-foreground">
                      {t("crawl.latestPage", "최근 페이지")}
                    </div>
                    <div className="truncate font-medium">
                      {progress.latest_page.title || progress.latest_page.url}
                    </div>
                    {progress.latest_page.page_type && (
                      <Badge variant="outline" className="mt-1">
                        {progress.latest_page.page_type}
                      </Badge>
                    )}
                  </div>
                )}

                {job.error && (
                  <div className="flex items-start gap-2 rounded-md border border-destructive bg-destructive/5 px-3 py-2 text-sm text-destructive">
                    <XCircle className="mt-0.5 h-4 w-4 flex-shrink-0" />
                    <span>{job.error}</span>
                  </div>
                )}

                {errors_.length > 0 && (
                  <details className="rounded-md border bg-background">
                    <summary className="cursor-pointer px-3 py-2 text-sm font-medium">
                      {t("crawl.errorsCount", "에러 {{count}}건", {
                        count: errors_.length,
                      })}
                    </summary>
                    <ul className="max-h-40 overflow-y-auto px-4 py-2 text-xs text-muted-foreground">
                      {errors_.map((e, i) => (
                        <li key={i} className="border-b py-1 last:border-0">
                          {e}
                        </li>
                      ))}
                    </ul>
                  </details>
                )}

                {terminal && job.status === "completed" && (
                  <div className="flex items-center gap-2 text-sm text-green-700">
                    <CheckCircle2 className="h-4 w-4" />
                    {t("crawl.doneHint", "크롤 완료. 구축 파이프라인으로 이동하세요.")}
                  </div>
                )}
              </div>
            )}
          </CardContent>
        </Card>
      </div>
    </div>
  );
}