"use client";

import React, { useState, useEffect } from "react";
import { CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
import { Badge } from "@/components/ui/badge";
import { Input } from "@/components/ui/input";
import { ArrowLeft, ArrowRight, Table, Search, Loader2 } from "lucide-react";
import { toast } from "sonner";

// API import
import { getTablesFromConnection, getBatchTablesWithColumns } from "@/lib/api/multiConnection";

// 타입 import
import { Connection, TableInfo } from "@/lib/types/multiConnection";

interface TableStepProps {
  fromConnection?: Connection;
  toConnection?: Connection;
  fromTable?: TableInfo;
  toTable?: TableInfo;
  onSelectTable: (type: "from" | "to", table: TableInfo) => void;
  onNext: () => void;
  onBack: () => void;
}

/**
 * 📋 2단계: 테이블 선택
 * - FROM/TO 테이블 선택
 * - 테이블 검색 기능
 * - 컬럼 수 정보 표시
 */
const TableStep: React.FC<TableStepProps> = ({
  fromConnection,
  toConnection,
  fromTable,
  toTable,
  onSelectTable,
  onNext,
  onBack,
}) => {
  const [fromTables, setFromTables] = useState<TableInfo[]>([]);
  const [toTables, setToTables] = useState<TableInfo[]>([]);
  const [fromSearch, setFromSearch] = useState("");
  const [toSearch, setToSearch] = useState("");
  const [isLoadingFrom, setIsLoadingFrom] = useState(false);
  const [isLoadingTo, setIsLoadingTo] = useState(false);
  const [tableColumnCounts, setTableColumnCounts] = useState<Record<string, number>>({});

  // FROM 테이블 목록 로드 (배치 조회)
  useEffect(() => {
    if (fromConnection) {
      const loadFromTables = async () => {
        try {
          setIsLoadingFrom(true);
          console.log("🚀 FROM 테이블 배치 조회 시작");

          // 배치 조회로 테이블 정보와 컬럼 수를 한번에 가져오기
          const batchResult = await getBatchTablesWithColumns(fromConnection.id);

          console.log("✅ FROM 테이블 배치 조회 완료:", batchResult);

          // TableInfo 형식으로 변환
          const tables: TableInfo[] = batchResult.map((item) => ({
            tableName: item.tableName,
            displayName: item.displayName || item.tableName,
          }));

          setFromTables(tables);

          // 컬럼 수 정보를 state에 저장
          const columnCounts: Record<string, number> = {};
          batchResult.forEach((item) => {
            columnCounts[`from_${item.tableName}`] = item.columnCount;
          });

          setTableColumnCounts((prev) => ({
            ...prev,
            ...columnCounts,
          }));

          console.log(`📊 FROM 테이블 ${tables.length}개 로드 완료, 컬럼 수:`, columnCounts);
        } catch (error) {
          console.error("FROM 테이블 목록 로드 실패:", error);
          toast.error("소스 테이블 목록을 불러오는데 실패했습니다.");
        } finally {
          setIsLoadingFrom(false);
        }
      };
      loadFromTables();
    }
  }, [fromConnection]);

  // TO 테이블 목록 로드 (배치 조회)
  useEffect(() => {
    if (toConnection) {
      const loadToTables = async () => {
        try {
          setIsLoadingTo(true);
          console.log("🚀 TO 테이블 배치 조회 시작");

          // 배치 조회로 테이블 정보와 컬럼 수를 한번에 가져오기
          const batchResult = await getBatchTablesWithColumns(toConnection.id);

          console.log("✅ TO 테이블 배치 조회 완료:", batchResult);

          // TableInfo 형식으로 변환
          const tables: TableInfo[] = batchResult.map((item) => ({
            tableName: item.tableName,
            displayName: item.displayName || item.tableName,
          }));

          setToTables(tables);

          // 컬럼 수 정보를 state에 저장
          const columnCounts: Record<string, number> = {};
          batchResult.forEach((item) => {
            columnCounts[`to_${item.tableName}`] = item.columnCount;
          });

          setTableColumnCounts((prev) => ({
            ...prev,
            ...columnCounts,
          }));

          console.log(`📊 TO 테이블 ${tables.length}개 로드 완료, 컬럼 수:`, columnCounts);
        } catch (error) {
          console.error("TO 테이블 목록 로드 실패:", error);
          toast.error("대상 테이블 목록을 불러오는데 실패했습니다.");
        } finally {
          setIsLoadingTo(false);
        }
      };
      loadToTables();
    }
  }, [toConnection]);

  // 테이블 필터링
  const filteredFromTables = fromTables.filter((table) =>
    (table.displayName || table.tableName).toLowerCase().includes(fromSearch.toLowerCase()),
  );

  const filteredToTables = toTables.filter((table) =>
    (table.displayName || table.tableName).toLowerCase().includes(toSearch.toLowerCase()),
  );

  const handleTableSelect = (type: "from" | "to", tableName: string) => {
    const tables = type === "from" ? fromTables : toTables;
    const table = tables.find((t) => t.tableName === tableName);
    if (table) {
      onSelectTable(type, table);
    }
  };

  const canProceed = fromTable && toTable;

  const renderTableItem = (table: TableInfo, type: "from" | "to") => {
    const displayName =
      table.displayName && table.displayName !== table.tableName ? table.displayName : table.tableName;

    const columnCount = tableColumnCounts[`${type}_${table.tableName}`];

    return (
      <div className="flex w-full items-center justify-between">
        <div className="flex items-center gap-2">
          <Table className="h-4 w-4" />
          <span>{displayName}</span>
        </div>
        <Badge variant="outline" className="text-xs">
          {columnCount !== undefined ? columnCount : table.columnCount || 0}개 컬럼
        </Badge>
      </div>
    );
  };

  return (
    <>
      <CardHeader>
        <CardTitle className="flex items-center gap-2">
          <Table className="h-5 w-5" />
          2단계: 테이블 선택
        </CardTitle>
        <p className="text-muted-foreground text-sm">연결된 데이터베이스에서 소스와 대상 테이블을 선택하세요.</p>
      </CardHeader>

      <CardContent className="max-h-[calc(100vh-400px)] min-h-[400px] space-y-6 overflow-y-auto">
        {/* FROM 테이블 선택 */}
        <div className="space-y-3">
          <div className="flex items-center justify-between">
            <h3 className="font-medium">FROM 테이블 (소스)</h3>
            <Badge variant="outline" className="text-xs">
              {fromConnection?.name}
            </Badge>
          </div>

          {/* 검색 */}
          <div className="relative">
            <Search className="text-muted-foreground absolute top-1/2 left-3 h-4 w-4 -translate-y-1/2 transform" />
            <Input
              placeholder="테이블 검색..."
              value={fromSearch}
              onChange={(e) => setFromSearch(e.target.value)}
              className="pl-9"
            />
          </div>

          {/* 테이블 선택 */}
          {isLoadingFrom ? (
            <div className="flex items-center justify-center py-4">
              <Loader2 className="mr-2 h-4 w-4 animate-spin" />
              <span className="text-sm">테이블 목록 로드 중...</span>
            </div>
          ) : (
            <Select value={fromTable?.tableName || ""} onValueChange={(value) => handleTableSelect("from", value)}>
              <SelectTrigger>
                <SelectValue placeholder="소스 테이블을 선택하세요" />
              </SelectTrigger>
              <SelectContent>
                {filteredFromTables.map((table) => (
                  <SelectItem key={table.tableName} value={table.tableName}>
                    {renderTableItem(table, "from")}
                  </SelectItem>
                ))}
              </SelectContent>
            </Select>
          )}

          {fromTable && (
            <div className="bg-muted/50 rounded-lg p-3">
              <div className="mb-2 flex items-center justify-between">
                <span className="font-medium">{fromTable.displayName || fromTable.tableName}</span>
                <Badge variant="secondary">
                  📊 {tableColumnCounts[`from_${fromTable.tableName}`] || fromTable.columnCount || 0}개 컬럼
                </Badge>
              </div>
              {fromTable.description && <p className="text-muted-foreground text-xs">{fromTable.description}</p>}
            </div>
          )}
        </div>

        {/* TO 테이블 선택 */}
        <div className="space-y-3">
          <div className="flex items-center justify-between">
            <h3 className="font-medium">TO 테이블 (대상)</h3>
            <Badge variant="outline" className="text-xs">
              {toConnection?.name}
            </Badge>
          </div>

          {/* 검색 */}
          <div className="relative">
            <Search className="text-muted-foreground absolute top-1/2 left-3 h-4 w-4 -translate-y-1/2 transform" />
            <Input
              placeholder="테이블 검색..."
              value={toSearch}
              onChange={(e) => setToSearch(e.target.value)}
              className="pl-9"
            />
          </div>

          {/* 테이블 선택 */}
          {isLoadingTo ? (
            <div className="flex items-center justify-center py-4">
              <Loader2 className="mr-2 h-4 w-4 animate-spin" />
              <span className="text-sm">테이블 목록 로드 중...</span>
            </div>
          ) : (
            <Select value={toTable?.tableName || ""} onValueChange={(value) => handleTableSelect("to", value)}>
              <SelectTrigger>
                <SelectValue placeholder="대상 테이블을 선택하세요" />
              </SelectTrigger>
              <SelectContent>
                {filteredToTables.map((table) => (
                  <SelectItem key={table.tableName} value={table.tableName}>
                    {renderTableItem(table, "to")}
                  </SelectItem>
                ))}
              </SelectContent>
            </Select>
          )}

          {toTable && (
            <div className="bg-muted/50 rounded-lg p-3">
              <div className="mb-2 flex items-center justify-between">
                <span className="font-medium">{toTable.displayName || toTable.tableName}</span>
                <Badge variant="secondary">
                  📊 {tableColumnCounts[`to_${toTable.tableName}`] || toTable.columnCount || 0}개 컬럼
                </Badge>
              </div>
              {toTable.description && <p className="text-muted-foreground text-xs">{toTable.description}</p>}
            </div>
          )}
        </div>

        {/* 테이블 매핑 표시 */}
        {fromTable && toTable && (
          <div className="bg-primary/5 border-primary/20 rounded-lg border p-4">
            <div className="flex items-center justify-center gap-4">
              <div className="text-center">
                <div className="font-medium">{fromTable.displayName || fromTable.tableName}</div>
                <div className="text-muted-foreground text-xs">
                  {tableColumnCounts[`from_${fromTable.tableName}`] || fromTable.columnCount || 0}개 컬럼
                </div>
              </div>

              <ArrowRight className="text-primary h-5 w-5" />

              <div className="text-center">
                <div className="font-medium">{toTable.displayName || toTable.tableName}</div>
                <div className="text-muted-foreground text-xs">
                  {tableColumnCounts[`to_${toTable.tableName}`] || toTable.columnCount || 0}개 컬럼
                </div>
              </div>
            </div>

            <div className="mt-3 text-center">
              <Badge variant="outline" className="text-primary">
                💡 테이블 매핑: {fromTable.displayName || fromTable.tableName} →{" "}
                {toTable.displayName || toTable.tableName}
              </Badge>
            </div>
          </div>
        )}

        {/* 네비게이션 버튼 */}
        <div className="flex justify-between pt-4">
          <Button variant="outline" onClick={onBack} className="flex items-center gap-2">
            <ArrowLeft className="h-4 w-4" />
            이전: 연결 선택
          </Button>

          <Button onClick={onNext} disabled={!canProceed} className="flex items-center gap-2">
            다음: 컬럼 매핑
            <ArrowRight className="h-4 w-4" />
          </Button>
        </div>
      </CardContent>
    </>
  );
};

export default TableStep;