"use client";

import * as React from "react";
import { zodResolver } from "@hookform/resolvers/zod";
import { useForm } from "react-hook-form";
import * as z from "zod";
import { toast } from "sonner";
import { v4 as uuidv4 } from 'uuid';
import { Dialog, DialogTrigger, DialogContent, DialogHeader, DialogTitle, DialogDescription, DialogFooter } from "@/components/ui/dialog";
import {
  Form,
  FormControl,
  FormField,
  FormItem,
  FormLabel,
  FormMessage,
  FormDescription,
} from "@/components/ui/form";
import { Input } from "@/components/ui/input";
import { Button } from "@/components/ui/button";
import { Checkbox } from "@/components/ui/checkbox";
import { Switch } from "@/components/ui/switch";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Dropzone,
  DropzoneZone,
  DropzoneUploadIcon,
  DropzoneTitle,
  DropzoneDescription,
  DropzoneInput
} from "@/components/ui/dropzone";
import { Progress } from "@/components/ui/progress";
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
import { Separator } from "@/components/ui/separator";
import { useRouter } from "next/navigation";
import { BUSINESS_UNITS } from "@/config/basicContractColumnsConfig";
import { getExistingTemplateNames } from "../service";

// ✅ 서버 액션 import

// 전체 템플릿 후보
const TEMPLATE_NAME_OPTIONS = [
  "준법서약 (한글)",
  "준법서약 (영문)",
  "기술자료 요구서", 
  "비밀유지 계약서",
  "표준하도급기본 계약서",
  "General GTC",
  "안전보건관리 약정서",
  "동반성장",
  "윤리규범 준수 서약서",
  "기술자료 동의서",
  "내국신용장 미개설 합의서",
  "직납자재 하도급대급등 연동제 의향서"
] as const;

const templateFormSchema = z.object({
  templateName: z.enum(TEMPLATE_NAME_OPTIONS, {
    required_error: "템플릿 이름을 선택해주세요.",
  }),
  legalReviewRequired: z.boolean().default(false),
  // 적용 범위
  shipBuildingApplicable: z.boolean().default(false),
  windApplicable: z.boolean().default(false),
  pcApplicable: z.boolean().default(false),
  nbApplicable: z.boolean().default(false),
  rcApplicable: z.boolean().default(false),
  gyApplicable: z.boolean().default(false),
  sysApplicable: z.boolean().default(false),
  infraApplicable: z.boolean().default(false),
  file: z.instanceof(File).optional(),
})
.refine((data) => {
  if (data.templateName !== "General GTC" && !data.file) return false;
  return true;
}, {
  message: "파일을 업로드해주세요.",
  path: ["file"],
})
.refine((data) => {
  if (data.file && data.file.size > 100 * 1024 * 1024) return false;
  return true;
}, {
  message: "파일 크기는 100MB 이하여야 합니다.",
  path: ["file"],
})
.refine((data) => {
  if (data.file) {
    const isValidType = data.file.type === 'application/msword' || 
      data.file.type === 'application/vnd.openxmlformats-officedocument.wordprocessingml.document';
    return isValidType;
  }
  return true;
}, {
  message: "워드 파일(.doc, .docx)만 업로드 가능합니다.",
  path: ["file"],
})
.refine((data) => {
  const scopeFields = [
    'shipBuildingApplicable', 'windApplicable', 'pcApplicable', 'nbApplicable',
    'rcApplicable', 'gyApplicable', 'sysApplicable', 'infraApplicable'
  ];
  return scopeFields.some(field => data[field as keyof typeof data] === true);
}, {
  message: "적어도 하나의 적용 범위를 선택해야 합니다.",
  path: ["shipBuildingApplicable"],
});

type TemplateFormValues = z.infer<typeof templateFormSchema>;

export function AddTemplateDialog() {
  const [open, setOpen] = React.useState(false);
  const [isLoading, setIsLoading] = React.useState(false);
  const [selectedFile, setSelectedFile] = React.useState<File | null>(null);
  const [uploadProgress, setUploadProgress] = React.useState(0);
  const [showProgress, setShowProgress] = React.useState(false);
  const [availableTemplateNames, setAvailableTemplateNames] = React.useState<typeof TEMPLATE_NAME_OPTIONS[number][]>(TEMPLATE_NAME_OPTIONS);
  const router = useRouter();

  // 기본값
  const defaultValues: Partial<TemplateFormValues> = {
    templateName: undefined,
    legalReviewRequired: false,
    shipBuildingApplicable: false,
    windApplicable: false,
    pcApplicable: false,
    nbApplicable: false,
    rcApplicable: false,
    gyApplicable: false,
    sysApplicable: false,
    infraApplicable: false,
  };

  const form = useForm<TemplateFormValues>({
    resolver: zodResolver(templateFormSchema),
    defaultValues,
    mode: "onChange",
  });

  // 🔸 마운트 시 이미 등록된 templateName 목록 가져와서 필터링
  React.useEffect(() => {
    let cancelled = false;
    (async () => {
      try {
        const usedNames = await getExistingTemplateNames();
        if (cancelled) return;

        // 이미 있는 이름 제외
        const filtered = TEMPLATE_NAME_OPTIONS.filter(name => !usedNames.includes(name));
        setAvailableTemplateNames(filtered);
      } catch (err) {
        console.error("Failed to fetch existing template names", err);
        // 실패 시 전체 옵션 보여주거나, 오류 알려주기
      }
    })();
    return () => { cancelled = true; };
  }, []);

  const handleFileChange = (files: File[]) => {
    if (files.length > 0) {
      const file = files[0];
      setSelectedFile(file);
      form.setValue("file", file);
    }
  };

  const handleSelectAllScopes = (checked: boolean) => {
    BUSINESS_UNITS.forEach(unit => {
      form.setValue(unit.key as keyof TemplateFormValues, checked);
    });
  };

  // 청크 업로드 설정
  const CHUNK_SIZE = 1 * 1024 * 1024;

  const uploadFileInChunks = async (file: File, fileId: string) => {
    const totalChunks = Math.ceil(file.size / CHUNK_SIZE);
    setShowProgress(true);
    setUploadProgress(0);

    for (let chunkIndex = 0; chunkIndex < totalChunks; chunkIndex++) {
      const start = chunkIndex * CHUNK_SIZE;
      const end = Math.min(start + CHUNK_SIZE, file.size);
      const chunk = file.slice(start, end);

      const formData = new FormData();
      formData.append('chunk', chunk);
      formData.append('filename', file.name);
      formData.append('chunkIndex', chunkIndex.toString());
      formData.append('totalChunks', totalChunks.toString());
      formData.append('fileId', fileId);

      const response = await fetch('/api/upload/basicContract/chunk', {
        method: 'POST',
        body: formData,
      });

      if (!response.ok) {
        throw new Error(`청크 업로드 실패: ${response.statusText}`);
      }

      const progress = Math.round(((chunkIndex + 1) / totalChunks) * 100);
      setUploadProgress(progress);

      const result = await response.json();
      if (chunkIndex === totalChunks - 1) {
        return result;
      }
    }
  };

  async function onSubmit(formData: TemplateFormValues) {
    setIsLoading(true);
    try {
      let uploadResult = null;

      if (formData.file) {
        const fileId = uuidv4();
        uploadResult = await uploadFileInChunks(formData.file, fileId);

        if (!uploadResult?.success) {
          throw new Error("파일 업로드에 실패했습니다.");
        }
      }

      const saveResponse = await fetch('/api/upload/basicContract/complete', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          templateName: formData.templateName,
          revision: 1,
          legalReviewRequired: formData.legalReviewRequired,
          shipBuildingApplicable: formData.shipBuildingApplicable,
          windApplicable: formData.windApplicable,
          pcApplicable: formData.pcApplicable,
          nbApplicable: formData.nbApplicable,
          rcApplicable: formData.rcApplicable,
          gyApplicable: formData.gyApplicable,
          sysApplicable: formData.sysApplicable,
          infraApplicable: formData.infraApplicable,
          status: "ACTIVE",
          fileName: uploadResult?.fileName || `${formData.templateName}_v1.docx`,
          filePath: uploadResult?.filePath || "",
        }),
        next: { tags: ["basic-contract-templates"] },
      });

      const saveResult = await saveResponse.json();
      if (!saveResult.success) {
        throw new Error(saveResult.error || "템플릿 정보 저장에 실패했습니다.");
      }

      toast.success('템플릿이 성공적으로 추가되었습니다.');
      form.reset();
      setSelectedFile(null);
      setOpen(false);
      setShowProgress(false);
      router.refresh();
    } catch (error) {
      console.error("Submit error:", error);
      toast.error(error instanceof Error ? error.message : "템플릿 추가 중 오류가 발생했습니다.");
    } finally {
      setIsLoading(false);
    }
  }

  React.useEffect(() => {
    if (!open) {
      form.reset();
      setSelectedFile(null);
      setShowProgress(false);
      setUploadProgress(0);
    }
  }, [open, form]);

  function handleDialogOpenChange(nextOpen: boolean) {
    if (!nextOpen) {
      form.reset();
    }
    setOpen(nextOpen);
  }

  const selectedScopesCount = BUSINESS_UNITS.filter(unit =>
    form.watch(unit.key as keyof TemplateFormValues)
  ).length;

  const templateNameIsRequired = form.watch("templateName") !== "General GTC";

  const isSubmitDisabled = isLoading ||
    !form.watch("templateName") ||
    (templateNameIsRequired && !form.watch("file")) ||
    !BUSINESS_UNITS.some(unit => form.watch(unit.key as keyof TemplateFormValues));

  return (
    <Dialog open={open} onOpenChange={handleDialogOpenChange}>
      <DialogTrigger asChild>
        <Button variant="default" size="sm">
          템플릿 추가
        </Button>
      </DialogTrigger>
      <DialogContent className="sm:max-w-[600px] h-[90vh] flex flex-col p-0">
        <DialogHeader className="p-6 pb-4 border-b">
          <DialogTitle>새 기본계약서 템플릿 추가</DialogTitle>
          <DialogDescription>
            템플릿 정보를 입력하고 계약서 파일을 업로드하세요. (리비전은 자동으로 1로 설정됩니다)
            <span className="text-red-500 mt-1 block text-sm">* 표시된 항목은 필수 입력사항입니다.</span>
          </DialogDescription>
        </DialogHeader>

        <div className="flex-1 overflow-y-auto px-6">
          <Form {...form}>
            <form onSubmit={form.handleSubmit(onSubmit)} className="space-y-6 py-4">
              {/* 기본 정보 */}
              <Card>
                <CardHeader>
                  <CardTitle className="text-lg">기본 정보</CardTitle>
                </CardHeader>
                <CardContent className="space-y-4">
                  <div className="grid grid-cols-1 gap-4">
                    <FormField
                      control={form.control}
                      name="templateName"
                      render={({ field }) => (
                        <FormItem>
                          <FormLabel>
                            템플릿 이름 <span className="text-red-500">*</span>
                          </FormLabel>
                          <Select onValueChange={field.onChange} value={field.value}>
                            <FormControl>
                              <SelectTrigger disabled={availableTemplateNames.length === 0}>
                                <SelectValue placeholder={
                                  availableTemplateNames.length === 0
                                    ? "사용 가능한 템플릿이 없습니다"
                                    : "템플릿 이름을 선택하세요"
                                } />
                              </SelectTrigger>
                            </FormControl>
                            <SelectContent>
                              {availableTemplateNames.map((option) => (
                                <SelectItem key={option} value={option}>
                                  {option}
                                </SelectItem>
                              ))}
                            </SelectContent>
                          </Select>
                          <FormDescription>
                            이미 등록되지 않은 템플릿만 표시됩니다. (리비전 1로 생성)
                          </FormDescription>
                          <FormMessage />
                        </FormItem>
                      )}
                    />
                  </div>

                  <FormField
                    control={form.control}
                    name="legalReviewRequired"
                    render={({ field }) => (
                      <FormItem className="flex flex-row items-center justify-between rounded-lg border p-3 shadow-sm">
                        <div className="space-y-0.5">
                          <FormLabel>법무검토 필요</FormLabel>
                          <FormDescription>
                            법무팀 검토가 필요한 템플릿인지 설정
                          </FormDescription>
                        </div>
                        <FormControl>
                          <Switch
                            checked={field.value}
                            onCheckedChange={field.onChange}
                          />
                        </FormControl>
                      </FormItem>
                    )}
                  />
                </CardContent>
              </Card>

              {/* 적용 범위 */}
              <Card>
                <CardHeader>
                  <CardTitle className="text-lg">
                    적용 범위 <span className="text-red-500">*</span>
                  </CardTitle>
                  <CardDescription>
                    이 템플릿이 적용될 사업부를 선택하세요. ({selectedScopesCount}개 선택됨)
                  </CardDescription>
                </CardHeader>
                <CardContent className="space-y-4">
                  <div className="flex items-center space-x-2">
                    <Checkbox 
                      id="select-all"
                      checked={selectedScopesCount === BUSINESS_UNITS.length}
                      onCheckedChange={handleSelectAllScopes}
                    />
                    <label htmlFor="select-all" className="text-sm font-medium">
                      전체 선택
                    </label>
                  </div>

                  <Separator />

                  <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
                    {BUSINESS_UNITS.map((unit) => (
                      <FormField
                        key={unit.key}
                        control={form.control}
                        name={unit.key as keyof TemplateFormValues}
                        render={({ field }) => (
                          <FormItem className="flex flex-row items-start space-x-3 space-y-0">
                            <FormControl>
                              <Checkbox
                                checked={field.value as boolean}
                                onCheckedChange={field.onChange}
                              />
                            </FormControl>
                            <div className="space-y-1 leading-none">
                              <FormLabel className="text-sm font-normal">
                                {unit.label}
                              </FormLabel>
                            </div>
                          </FormItem>
                        )}
                      />
                    ))}
                  </div>

                  {form.formState.errors.shipBuildingApplicable && (
                    <p className="text-sm text-destructive">
                      {form.formState.errors.shipBuildingApplicable.message}
                    </p>
                  )}
                </CardContent>
              </Card>

              {/* 파일 업로드 */}
              <Card>
                <CardHeader>
                  <CardTitle className="text-lg">파일 업로드</CardTitle>
                  <CardDescription>
                    {form.watch("templateName") === "General GTC" 
                      ? "General GTC는 파일 업로드가 선택사항입니다"
                      : "템플릿 파일을 업로드하세요"}
                  </CardDescription>
                </CardHeader>
                <CardContent>
                  <FormField
                    control={form.control}
                    name="file"
                    render={() => (
                      <FormItem>
                        <FormLabel>
                          템플릿 파일 
                          {form.watch("templateName") !== "General GTC" && (
                            <span className="text-red-500"> *</span>
                          )}
                          {form.watch("templateName") === "General GTC" && (
                            <span className="text-muted-foreground"> (선택사항)</span>
                          )}
                        </FormLabel>
                        <FormControl>
                          <Dropzone
                            onDrop={handleFileChange}
                            accept={{
                              'application/msword': ['.doc'],
                              'application/vnd.openxmlformats-officedocument.wordprocessingml.document': ['.docx']
                            }}
                          >
                            <DropzoneZone>
                              <DropzoneUploadIcon className="h-10 w-10 text-muted-foreground" />
                              <DropzoneTitle>
                                {selectedFile ? selectedFile.name : "워드 파일을 여기에 드래그하세요"}
                              </DropzoneTitle>
                              <DropzoneDescription>
                                {selectedFile
                                  ? `파일 크기: ${(selectedFile.size / (1024 * 1024)).toFixed(2)} MB`
                                  : form.watch("templateName") === "General GTC"
                                    ? "또는 클릭하여 워드 파일(.doc, .docx)을 선택하세요 (선택사항, 최대 100MB)"
                                    : "또는 클릭하여 워드 파일(.doc, .docx)을 선택하세요 (최대 100MB)"}
                              </DropzoneDescription>
                              <DropzoneInput />
                            </DropzoneZone>
                          </Dropzone>
                        </FormControl>
                        <FormMessage />
                      </FormItem>
                    )}
                  />

                  {showProgress && (
                    <div className="space-y-2 mt-4">
                      <div className="flex justify-between text-sm">
                        <span>업로드 진행률</span>
                        <span>{uploadProgress}%</span>
                      </div>
                      <Progress value={uploadProgress} />
                    </div>
                  )}
                </CardContent>
              </Card>
            </form>
          </Form>
        </div>

        <DialogFooter className="p-6 pt-4 border-t">
          <Button
            type="button"
            variant="outline"
            onClick={() => setOpen(false)}
            disabled={isLoading}
          >
            취소
          </Button>
          <Button
            type="button"
            onClick={form.handleSubmit(onSubmit)}
            disabled={isSubmitDisabled}
          >
            {isLoading ? "처리 중..." : "추가"}
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}
