import { memo, useEffect, useState } from "react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Checkbox } from "@/components/ui/checkbox";
import {
  DropdownMenu,
  DropdownMenuTrigger,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuLabel,
} from "@/components/ui/dropdown-menu";
import {
  Dialog,
  DialogContent,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { requestTranslations } from "@/lib/ai";
import { ButtonGroup } from "../ui/button-group";

type Props = {
  open: boolean;
  onOpenChange: (next: boolean) => void;
  languages: string[];
  paths: string[];
  prompt: string | undefined;
  initialSelectedLanguages?: string[];
  getExistingByPath?: (path: string) => Record<string, string>;
  onConfirm: (
    result: Record<string, Record<string, string>>,
    options: { overwrite: boolean; selectedLanguages: string[] }
  ) => Promise<void> | void;
};

function AiTranslateModalImpl({ open, onOpenChange, languages, paths, prompt, initialSelectedLanguages, getExistingByPath, onConfirm }: Props) {
  const [inputsByKey, setInputsByKey] = useState<Record<string, string>>({});
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [selectedLangs, setSelectedLangs] = useState<string[]>([]);
  const [overwrite, setOverwrite] = useState(false);
  const [existingCache, setExistingCache] = useState<Record<string, { lang: string; text: string }[]>>({});
  const MAX_ITEMS = 50;
  const overLimit = paths.length > MAX_ITEMS;

  useEffect(() => {
    if (open) {
      const init: Record<string, string> = {};
      for (const p of paths) init[p] = inputsByKey[p] ?? "";
      setInputsByKey(init);

      // 初始化默认勾选语言
      const initSelected = (initialSelectedLanguages && initialSelectedLanguages.length > 0)
        ? initialSelectedLanguages
        : languages;

      setSelectedLangs(initSelected);
      setOverwrite(false);
      setExistingCache({});
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [open, paths.join("|")]);

  function loadExistingForPath(path: string) {
    if (existingCache[path]) return;
    const map = getExistingByPath?.(path) ?? {};
    const arr = Object.entries(map)
      .map(([lang, text]) => ({ lang, text }))
      .filter((it) => typeof it.text === "string" && it.text.trim() !== "");
    setExistingCache((old) => ({ ...old, [path]: arr }));
  }

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault();
    if (overLimit) {
      setError(`一次最多支持 ${MAX_ITEMS} 条`);
      return;
    }
    const items = paths.map((key) => ({ key, text: (inputsByKey[key] ?? "").trim() }));
    if (items.some((it) => !it.text)) {
      setError("请为所有条目输入原文");
      return;
    }
    if (languages.length === 0) {
      setError("当前项目暂无目标语言");
      return;
    }
    if (selectedLangs.length === 0) {
      setError("请选择目标语言");
      return;
    }
    setLoading(true);
    setError(null);
    try {
      const result = await requestTranslations({ items, languages: selectedLangs, prompt });
      await onConfirm(result, { overwrite, selectedLanguages: selectedLangs });
      setInputsByKey({});
      onOpenChange(false);
    } catch (e) {
      setError((e as Error)?.message ?? "AI 翻译失败");
    } finally {
      setLoading(false);
    }
  }

  return (
    <Dialog
      open={open}
      onOpenChange={(v) => {
        if (!loading) {
          onOpenChange(v);
          if (!v) setError(null);
        }
      }}
    >
      <DialogContent className="max-w-3xl">
        <DialogHeader>
          <DialogTitle>{`AI 翻译 — 已选 ${paths.length} 条`}</DialogTitle>
        </DialogHeader>
        <form onSubmit={handleSubmit} className="space-y-4">
          <div className="space-y-4 max-h-[50vh] overflow-auto pr-1">
            {paths.map((p) => (
              <div key={p} className="flex flex-col gap-2">
                <div className="truncate font-mono text-xs text-muted-foreground">
                  {p}
                </div>
                <ButtonGroup className="w-full">
                  <Input
                    className="grow"
                    value={inputsByKey[p] ?? ""}
                    onChange={(e) =>
                      setInputsByKey((old) => ({ ...old, [p]: e.target.value }))
                    }
                    placeholder="请输入原文本"
                    aria-label={`原文 ${p}`}
                  />
                  <DropdownMenu
                    onOpenChange={(open) => {
                      if (open) loadExistingForPath(p);
                    }}
                  >
                    <DropdownMenuTrigger asChild>
                      <Button
                        type="button"
                        variant="outline"
                        aria-label="使用已有翻译"
                      >
                        使用已有翻译
                      </Button>
                    </DropdownMenuTrigger>
                    <DropdownMenuContent
                      align="end"
                      className="max-w-96 whitespace-normal wrap-break-word"
                    >
                      {(existingCache[p]?.length ?? 0) === 0 ? (
                        <DropdownMenuItem disabled>无可用内容</DropdownMenuItem>
                      ) : (
                        (existingCache[p] || []).map((opt) => (
                          <>
                            <DropdownMenuLabel>
                              {opt.lang}
                            </DropdownMenuLabel>
                            <DropdownMenuItem
                              key={`${p}:${opt.lang}`}
                              onClick={() =>
                                setInputsByKey((old) => ({
                                  ...old,
                                  [p]: opt.text,
                                }))
                              }
                              title={opt.text}
                            >
                              <span className="truncate block">{opt.text}</span>
                            </DropdownMenuItem>
                          </>
                        ))
                      )}
                    </DropdownMenuContent>
                  </DropdownMenu>
                </ButtonGroup>
              </div>
            ))}
          </div>
          <div className="space-y-2">
            <div className="text-xs text-muted-foreground">
              请选择目标语言：
            </div>
            <div className="flex flex-wrap gap-3">
              {languages.map((lang) => {
                const checked = selectedLangs.includes(lang);

                return (
                  <label
                    key={lang}
                    className="inline-flex items-center gap-2 select-none"
                  >
                    <Checkbox
                      checked={checked}
                      onCheckedChange={(v) => {
                        setSelectedLangs((old) => {
                          const set = new Set(old);
                          if (v) set.add(lang);
                          else set.delete(lang);
                          return Array.from(set);
                        });
                      }}
                    />
                    <span className="text-sm">{lang}</span>
                  </label>
                );
              })}
            </div>
          </div>
          <label className="inline-flex items-center gap-2 select-none">
            <Checkbox
              checked={overwrite}
              onCheckedChange={(v) => setOverwrite(!!v)}
            />
            <span className="text-sm">覆盖已有翻译（默认仅填充缺失项）</span>
          </label>

          {(error || overLimit) && (
            <div className="text-sm text-red-600" role="alert">
              {error}
            </div>
          )}

          <DialogFooter>
            <Button
              type="button"
              variant="outline"
              onClick={() => {
                onOpenChange(false);
                setError(null);
              }}
              disabled={loading}
            >
              取消
            </Button>
            <Button type="submit" disabled={loading || overLimit}>
              {loading ? "翻译中..." : "生成翻译"}
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}

export const AiTranslateModal = memo(AiTranslateModalImpl);