"use client";

/**
 * UnifiedSelect
 * 
 * 통합 선택 컴포넌트
 * - dropdown: 드롭다운 선택
 * - radio: 라디오 버튼 그룹
 * - check: 체크박스 그룹
 * - tag: 태그 선택
 * - toggle: 토글 스위치
 * - swap: 스왑 선택 (좌우 이동)
 */

import React, { forwardRef, useCallback, useContext, useEffect, useMemo, useState } from "react";
import { Label } from "@/components/ui/label";
import { RadioGroup, RadioGroupItem } from "@/components/ui/radio-group";
import { Checkbox } from "@/components/ui/checkbox";
import { Switch } from "@/components/ui/switch";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Command, CommandEmpty, CommandGroup, CommandInput, CommandItem, CommandList } from "@/components/ui/command";
import { Popover, PopoverContent, PopoverTrigger } from "@/components/ui/popover";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
import { cn } from "@/lib/utils";
import { UnifiedSelectProps, SelectOption } from "@/types/unified-components";
import { Check, ChevronsUpDown, X, ArrowLeftRight } from "lucide-react";
import { apiClient } from "@/lib/api/client";
import UnifiedFormContext from "./UnifiedFormContext";

/**
 * 드롭다운 선택 컴포넌트
 */
const DropdownSelect = forwardRef<HTMLButtonElement, {
  options: SelectOption[];
  value?: string | string[];
  onChange?: (value: string | string[]) => void;
  placeholder?: string;
  searchable?: boolean;
  multiple?: boolean;
  maxSelect?: number;
  allowClear?: boolean;
  disabled?: boolean;
  className?: string;
}>(({ 
  options, 
  value, 
  onChange, 
  placeholder = "선택", 
  searchable, 
  multiple, 
  maxSelect,
  allowClear = true,
  disabled, 
  className 
}, ref) => {
  const [open, setOpen] = useState(false);

  // 단일 선택 + 검색 불가능 → 기본 Select 사용
  if (!searchable && !multiple) {
    return (
      <Select
        value={typeof value === "string" ? value : value?.[0] ?? ""}
        onValueChange={(v) => onChange?.(v)}
        disabled={disabled}
      >
        <SelectTrigger ref={ref} className={cn("h-10", className)}>
          <SelectValue placeholder={placeholder} />
        </SelectTrigger>
        <SelectContent>
          {options.map((option) => (
            <SelectItem key={option.value} value={option.value}>
              {option.label}
            </SelectItem>
          ))}
        </SelectContent>
      </Select>
    );
  }

  // 검색 가능 또는 다중 선택 → Combobox 사용
  const selectedValues = useMemo(() => {
    if (!value) return [];
    return Array.isArray(value) ? value : [value];
  }, [value]);

  const selectedLabels = useMemo(() => {
    return selectedValues
      .map((v) => options.find((o) => o.value === v)?.label)
      .filter(Boolean) as string[];
  }, [selectedValues, options]);

  const handleSelect = useCallback((selectedValue: string) => {
    if (multiple) {
      const newValues = selectedValues.includes(selectedValue)
        ? selectedValues.filter((v) => v !== selectedValue)
        : maxSelect && selectedValues.length >= maxSelect
          ? selectedValues
          : [...selectedValues, selectedValue];
      onChange?.(newValues);
    } else {
      onChange?.(selectedValue);
      setOpen(false);
    }
  }, [multiple, selectedValues, maxSelect, onChange]);

  const handleClear = useCallback((e: React.MouseEvent) => {
    e.stopPropagation();
    onChange?.(multiple ? [] : "");
  }, [multiple, onChange]);

  return (
    <Popover open={open} onOpenChange={setOpen}>
      <PopoverTrigger asChild>
        <Button
          ref={ref}
          variant="outline"
          role="combobox"
          aria-expanded={open}
          disabled={disabled}
          className={cn("h-10 w-full justify-between font-normal", className)}
        >
          <span className="truncate flex-1 text-left">
            {selectedLabels.length > 0
              ? multiple 
                ? `${selectedLabels.length}개 선택됨`
                : selectedLabels[0]
              : placeholder}
          </span>
          <div className="flex items-center gap-1 ml-2">
            {allowClear && selectedValues.length > 0 && (
              <X 
                className="h-4 w-4 opacity-50 hover:opacity-100" 
                onClick={handleClear}
              />
            )}
            <ChevronsUpDown className="h-4 w-4 shrink-0 opacity-50" />
          </div>
        </Button>
      </PopoverTrigger>
      <PopoverContent className="p-0" style={{ width: "var(--radix-popover-trigger-width)" }} align="start">
        <Command
          filter={(value, search) => {
            // value는 CommandItem의 value (라벨)
            // search는 검색어
            if (!search) return 1;
            const normalizedValue = value.toLowerCase();
            const normalizedSearch = search.toLowerCase();
            if (normalizedValue.includes(normalizedSearch)) return 1;
            return 0;
          }}
        >
          {searchable && <CommandInput placeholder="검색..." className="h-9" />}
          <CommandList>
            <CommandEmpty>검색 결과가 없습니다.</CommandEmpty>
            <CommandGroup>
              {options.map((option) => {
                const displayLabel = option.label || option.value || "(빈 값)";
                return (
                  <CommandItem
                    key={option.value}
                    value={displayLabel}
                    onSelect={() => handleSelect(option.value)}
                  >
                    <Check
                      className={cn(
                        "mr-2 h-4 w-4",
                        selectedValues.includes(option.value) ? "opacity-100" : "opacity-0"
                      )}
                    />
                    {displayLabel}
                  </CommandItem>
                );
              })}
            </CommandGroup>
          </CommandList>
        </Command>
      </PopoverContent>
    </Popover>
  );
});
DropdownSelect.displayName = "DropdownSelect";

/**
 * 라디오 선택 컴포넌트
 */
const RadioSelect = forwardRef<HTMLDivElement, {
  options: SelectOption[];
  value?: string;
  onChange?: (value: string) => void;
  disabled?: boolean;
  className?: string;
}>(({ options, value, onChange, disabled, className }, ref) => {
  return (
    <RadioGroup
      ref={ref}
      value={value ?? ""}
      onValueChange={onChange}
      disabled={disabled}
      className={cn("flex flex-wrap gap-4", className)}
    >
      {options.map((option) => (
        <div key={option.value} className="flex items-center space-x-2">
          <RadioGroupItem value={option.value} id={`radio-${option.value}`} />
          <Label htmlFor={`radio-${option.value}`} className="text-sm cursor-pointer">
            {option.label}
          </Label>
        </div>
      ))}
    </RadioGroup>
  );
});
RadioSelect.displayName = "RadioSelect";

/**
 * 체크박스 선택 컴포넌트
 */
const CheckSelect = forwardRef<HTMLDivElement, {
  options: SelectOption[];
  value?: string[];
  onChange?: (value: string[]) => void;
  maxSelect?: number;
  disabled?: boolean;
  className?: string;
}>(({ options, value = [], onChange, maxSelect, disabled, className }, ref) => {
  const handleChange = useCallback((optionValue: string, checked: boolean) => {
    if (checked) {
      if (maxSelect && value.length >= maxSelect) return;
      onChange?.([...value, optionValue]);
    } else {
      onChange?.(value.filter((v) => v !== optionValue));
    }
  }, [value, maxSelect, onChange]);

  return (
    <div ref={ref} className={cn("flex flex-wrap gap-4", className)}>
      {options.map((option) => (
        <div key={option.value} className="flex items-center space-x-2">
          <Checkbox
            id={`check-${option.value}`}
            checked={value.includes(option.value)}
            onCheckedChange={(checked) => handleChange(option.value, checked as boolean)}
            disabled={disabled || (maxSelect && value.length >= maxSelect && !value.includes(option.value))}
          />
          <Label htmlFor={`check-${option.value}`} className="text-sm cursor-pointer">
            {option.label}
          </Label>
        </div>
      ))}
    </div>
  );
});
CheckSelect.displayName = "CheckSelect";

/**
 * 태그 선택 컴포넌트
 */
const TagSelect = forwardRef<HTMLDivElement, {
  options: SelectOption[];
  value?: string[];
  onChange?: (value: string[]) => void;
  maxSelect?: number;
  disabled?: boolean;
  className?: string;
}>(({ options, value = [], onChange, maxSelect, disabled, className }, ref) => {
  const handleToggle = useCallback((optionValue: string) => {
    const isSelected = value.includes(optionValue);
    if (isSelected) {
      onChange?.(value.filter((v) => v !== optionValue));
    } else {
      if (maxSelect && value.length >= maxSelect) return;
      onChange?.([...value, optionValue]);
    }
  }, [value, maxSelect, onChange]);

  return (
    <div ref={ref} className={cn("flex flex-wrap gap-2", className)}>
      {options.map((option) => {
        const isSelected = value.includes(option.value);
        return (
          <Badge
            key={option.value}
            variant={isSelected ? "default" : "outline"}
            className={cn(
              "cursor-pointer transition-colors",
              disabled && "opacity-50 cursor-not-allowed"
            )}
            onClick={() => !disabled && handleToggle(option.value)}
          >
            {option.label}
            {isSelected && <X className="ml-1 h-3 w-3" />}
          </Badge>
        );
      })}
    </div>
  );
});
TagSelect.displayName = "TagSelect";

/**
 * 토글 선택 컴포넌트 (Boolean용)
 */
const ToggleSelect = forwardRef<HTMLDivElement, {
  options: SelectOption[];
  value?: string;
  onChange?: (value: string) => void;
  disabled?: boolean;
  className?: string;
}>(({ options, value, onChange, disabled, className }, ref) => {
  // 토글은 2개 옵션만 지원
  const [offOption, onOption] = options.length >= 2 
    ? [options[0], options[1]] 
    : [{ value: "false", label: "아니오" }, { value: "true", label: "예" }];

  const isOn = value === onOption.value;

  return (
    <div ref={ref} className={cn("flex items-center gap-3", className)}>
      <span className={cn("text-sm", !isOn && "font-medium")}>{offOption.label}</span>
      <Switch
        checked={isOn}
        onCheckedChange={(checked) => onChange?.(checked ? onOption.value : offOption.value)}
        disabled={disabled}
      />
      <span className={cn("text-sm", isOn && "font-medium")}>{onOption.label}</span>
    </div>
  );
});
ToggleSelect.displayName = "ToggleSelect";

/**
 * 스왑 선택 컴포넌트 (좌우 이동 방식)
 */
const SwapSelect = forwardRef<HTMLDivElement, {
  options: SelectOption[];
  value?: string[];
  onChange?: (value: string[]) => void;
  maxSelect?: number;
  disabled?: boolean;
  className?: string;
}>(({ options, value = [], onChange, disabled, className }, ref) => {
  const available = useMemo(() => 
    options.filter((o) => !value.includes(o.value)),
    [options, value]
  );

  const selected = useMemo(() => 
    options.filter((o) => value.includes(o.value)),
    [options, value]
  );

  const handleMoveRight = useCallback((optionValue: string) => {
    onChange?.([...value, optionValue]);
  }, [value, onChange]);

  const handleMoveLeft = useCallback((optionValue: string) => {
    onChange?.(value.filter((v) => v !== optionValue));
  }, [value, onChange]);

  const handleMoveAllRight = useCallback(() => {
    onChange?.(options.map((o) => o.value));
  }, [options, onChange]);

  const handleMoveAllLeft = useCallback(() => {
    onChange?.([]);
  }, [onChange]);

  return (
    <div ref={ref} className={cn("flex gap-2 items-stretch", className)}>
      {/* 왼쪽: 선택 가능 */}
      <div className="flex-1 border rounded-md">
        <div className="p-2 bg-muted text-xs font-medium border-b">선택 가능</div>
        <div className="p-2 space-y-1 max-h-40 overflow-y-auto">
          {available.map((option) => (
            <div
              key={option.value}
              className={cn(
                "p-2 text-sm rounded cursor-pointer hover:bg-accent",
                disabled && "opacity-50 cursor-not-allowed"
              )}
              onClick={() => !disabled && handleMoveRight(option.value)}
            >
              {option.label}
            </div>
          ))}
          {available.length === 0 && (
            <div className="text-xs text-muted-foreground p-2">항목 없음</div>
          )}
        </div>
      </div>

      {/* 중앙: 이동 버튼 */}
      <div className="flex flex-col gap-1 justify-center">
        <Button 
          variant="outline" 
          size="icon" 
          className="h-8 w-8"
          onClick={handleMoveAllRight}
          disabled={disabled || available.length === 0}
        >
          <ArrowLeftRight className="h-4 w-4 rotate-180" />
        </Button>
        <Button 
          variant="outline" 
          size="icon" 
          className="h-8 w-8"
          onClick={handleMoveAllLeft}
          disabled={disabled || selected.length === 0}
        >
          <ArrowLeftRight className="h-4 w-4" />
        </Button>
      </div>

      {/* 오른쪽: 선택됨 */}
      <div className="flex-1 border rounded-md">
        <div className="p-2 bg-primary/10 text-xs font-medium border-b">선택됨</div>
        <div className="p-2 space-y-1 max-h-40 overflow-y-auto">
          {selected.map((option) => (
            <div
              key={option.value}
              className={cn(
                "p-2 text-sm rounded cursor-pointer hover:bg-accent flex justify-between items-center",
                disabled && "opacity-50 cursor-not-allowed"
              )}
              onClick={() => !disabled && handleMoveLeft(option.value)}
            >
              <span>{option.label}</span>
              <X className="h-3 w-3 opacity-50" />
            </div>
          ))}
          {selected.length === 0 && (
            <div className="text-xs text-muted-foreground p-2">선택 없음</div>
          )}
        </div>
      </div>
    </div>
  );
});
SwapSelect.displayName = "SwapSelect";

/**
 * 메인 UnifiedSelect 컴포넌트
 */
export const UnifiedSelect = forwardRef<HTMLDivElement, UnifiedSelectProps>(
  (props, ref) => {
    const {
      id,
      label,
      required,
      readonly,
      disabled,
      style,
      size,
      config: configProp,
      value,
      onChange,
    } = props;

    // config가 없으면 기본값 사용
    const config = configProp || { mode: "dropdown" as const, source: "static" as const, options: [] };

    const [options, setOptions] = useState<SelectOption[]>(config.options || []);
    const [loading, setLoading] = useState(false);
    const [optionsLoaded, setOptionsLoaded] = useState(false);

    // 옵션 로딩에 필요한 값들만 추출 (객체 참조 대신 원시값 사용)
    // category 소스는 code로 자동 변환 (카테고리 → 공통코드 통합)
    const rawSource = config.source;
    const categoryTable = (config as any).categoryTable;
    const categoryColumn = (config as any).categoryColumn;
    
    // category 소스인 경우 code로 변환하고 codeGroup을 자동 생성
    const source = rawSource === "category" ? "code" : rawSource;
    const codeGroup = rawSource === "category" && categoryTable && categoryColumn
      ? `${categoryTable.toUpperCase()}_${categoryColumn.toUpperCase()}`
      : config.codeGroup;
    
    const entityTable = config.entityTable;
    const entityValueColumn = config.entityValueColumn || config.entityValueField;
    const entityLabelColumn = config.entityLabelColumn || config.entityLabelField;
    const table = config.table;
    const valueColumn = config.valueColumn;
    const labelColumn = config.labelColumn;
    const apiEndpoint = config.apiEndpoint;
    const staticOptions = config.options;
    
    // 계층 코드 연쇄 선택 관련
    const hierarchical = config.hierarchical;
    const parentField = config.parentField;
    
    // FormContext에서 부모 필드 값 가져오기 (Context가 없으면 null)
    const formContext = useContext(UnifiedFormContext);
    
    // 부모 필드의 값 계산
    const parentValue = useMemo(() => {
      if (!hierarchical || !parentField) return null;
      
      // FormContext가 있으면 거기서 값 가져오기
      if (formContext) {
        const val = formContext.getValue(parentField);
        return val as string | null;
      }
      
      return null;
    }, [hierarchical, parentField, formContext]);

    // 데이터 소스에 따른 옵션 로딩 (원시값 의존성만 사용)
    useEffect(() => {
      // 계층 구조인 경우 부모 값이 변경되면 다시 로드
      if (hierarchical && source === "code") {
        setOptionsLoaded(false);
      }
    }, [parentValue, hierarchical, source]);

    useEffect(() => {
      // 이미 로드된 경우 스킵 (static 제외, 계층 구조 제외)
      if (optionsLoaded && source !== "static") {
        return;
      }

      const loadOptions = async () => {
        if (source === "static") {
          setOptions(staticOptions || []);
          setOptionsLoaded(true);
          return;
        }

        setLoading(true);
        try {
          let fetchedOptions: SelectOption[] = [];

          if (source === "code" && codeGroup) {
            // 계층 구조 사용 시 자식 코드만 로드
            if (hierarchical) {
              const params = new URLSearchParams();
              if (parentValue) {
                params.append("parentCodeValue", parentValue);
              }
              const queryString = params.toString();
              const url = `/common-codes/categories/${codeGroup}/children${queryString ? `?${queryString}` : ""}`;
              const response = await apiClient.get(url);
              const data = response.data;
              if (data.success && data.data) {
                fetchedOptions = data.data.map((item: { value: string; label: string; hasChildren: boolean }) => ({
                  value: item.value,
                  label: item.label,
                }));
              }
            } else {
              // 일반 공통코드에서 로드 (올바른 API 경로: /common-codes/categories/:categoryCode/options)
              const response = await apiClient.get(`/common-codes/categories/${codeGroup}/options`);
              const data = response.data;
              if (data.success && data.data) {
                fetchedOptions = data.data.map((item: { value: string; label: string }) => ({
                  value: item.value,
                  label: item.label,
                }));
              }
            }
          } else if (source === "db" && table) {
            // DB 테이블에서 로드
            const response = await apiClient.get(`/entity/${table}/options`, {
              params: {
                value: valueColumn || "id",
                label: labelColumn || "name",
              },
            });
            const data = response.data;
            if (data.success && data.data) {
              fetchedOptions = data.data;
            }
          } else if (source === "entity" && entityTable) {
            // 엔티티(참조 테이블)에서 로드
            const valueCol = entityValueColumn || "id";
            const labelCol = entityLabelColumn || "name";
            const response = await apiClient.get(`/entity/${entityTable}/options`, {
              params: {
                value: valueCol,
                label: labelCol,
              },
            });
            const data = response.data;
            if (data.success && data.data) {
              fetchedOptions = data.data;
            }
          } else if (source === "api" && apiEndpoint) {
            // 외부 API에서 로드
            const response = await apiClient.get(apiEndpoint);
            const data = response.data;
            if (Array.isArray(data)) {
              fetchedOptions = data;
            }
          }

          setOptions(fetchedOptions);
          setOptionsLoaded(true);
        } catch (error) {
          console.error("옵션 로딩 실패:", error);
          setOptions([]);
        } finally {
          setLoading(false);
        }
      };

        loadOptions();
    }, [source, entityTable, entityValueColumn, entityLabelColumn, codeGroup, table, valueColumn, labelColumn, apiEndpoint, staticOptions, optionsLoaded, hierarchical, parentValue]);

    // 모드별 컴포넌트 렌더링
    const renderSelect = () => {
      if (loading) {
        return <div className="h-10 flex items-center text-sm text-muted-foreground">로딩 중...</div>;
      }

      const isDisabled = disabled || readonly;

      switch (config.mode) {
        case "dropdown":
          return (
            <DropdownSelect
              options={options}
              value={value}
              onChange={onChange}
              placeholder="선택"
              searchable={config.searchable}
              multiple={config.multiple}
              maxSelect={config.maxSelect}
              allowClear={config.allowClear}
              disabled={isDisabled}
            />
          );

        case "radio":
          return (
            <RadioSelect
              options={options}
              value={typeof value === "string" ? value : value?.[0]}
              onChange={(v) => onChange?.(v)}
              disabled={isDisabled}
            />
          );

        case "check":
          return (
            <CheckSelect
              options={options}
              value={Array.isArray(value) ? value : value ? [value] : []}
              onChange={onChange}
              maxSelect={config.maxSelect}
              disabled={isDisabled}
            />
          );

        case "tag":
          return (
            <TagSelect
              options={options}
              value={Array.isArray(value) ? value : value ? [value] : []}
              onChange={onChange}
              maxSelect={config.maxSelect}
              disabled={isDisabled}
            />
          );

        case "toggle":
          return (
            <ToggleSelect
              options={options}
              value={typeof value === "string" ? value : value?.[0]}
              onChange={(v) => onChange?.(v)}
              disabled={isDisabled}
            />
          );

        case "swap":
          return (
            <SwapSelect
              options={options}
              value={Array.isArray(value) ? value : value ? [value] : []}
              onChange={onChange}
              maxSelect={config.maxSelect}
              disabled={isDisabled}
            />
          );

        default:
          return (
            <DropdownSelect
              options={options}
              value={value}
              onChange={onChange}
              disabled={isDisabled}
            />
          );
      }
    };

    const showLabel = label && style?.labelDisplay !== false;
    const componentWidth = size?.width || style?.width;
    const componentHeight = size?.height || style?.height;

    return (
      <div
        ref={ref}
        id={id}
        className="flex flex-col"
        style={{
          width: componentWidth,
          height: componentHeight,
        }}
      >
        {showLabel && (
          <Label
            htmlFor={id}
            style={{
              fontSize: style?.labelFontSize,
              color: style?.labelColor,
              fontWeight: style?.labelFontWeight,
              marginBottom: style?.labelMarginBottom,
            }}
            className="text-sm font-medium flex-shrink-0"
          >
            {label}
            {required && <span className="text-orange-500 ml-0.5">*</span>}
          </Label>
        )}
        <div className="flex-1 min-h-0">
          {renderSelect()}
        </div>
      </div>
    );
  }
);

UnifiedSelect.displayName = "UnifiedSelect";

export default UnifiedSelect;