// app/api/ocr/utils/tableExtraction.ts
// 완전한 테이블 추출 로직 구현

interface ExtractedRow {
  no: string;
  identificationNo: string;
  tagNo: string;
  jointNo: string;
  jointType: string;
  weldingDate: string;
  confidence: number;
  sourceTable: number;
  sourceRow: number;
}

interface TableCell {
  cellTextLines: Array<{
    cellWords: Array<{
      inferText: string;
      inferConfidence: number;
    }>;
  }>;
  rowIndex: number;
  columnIndex: number;
  rowSpan: number;
  columnSpan: number;
  inferConfidence: number;
}

interface OCRTable {
  cells: TableCell[];
  inferConfidence: number;
}

interface ColumnMapping {
  no: number;
  identification: number;
  tagNo: number;
  jointNo: number;
  jointType: number;
  weldingDate: number;
}

// 메인 테이블 추출 함수
export async function extractTablesFromOCR(ocrResult: any): Promise<ExtractedRow[][]> {
  const extractedTables: ExtractedRow[][] = [];
  const warnings: string[] = [];

  if (!ocrResult || !ocrResult.images) {
    console.warn('No OCR images found in result');
    return [];
  }

  for (let imageIndex = 0; imageIndex < ocrResult.images.length; imageIndex++) {
    const image = ocrResult.images[imageIndex];
    
    if (!image.tables || image.tables.length === 0) {
      console.warn(`No tables found in image ${imageIndex}`);
      continue;
    }

    for (let tableIndex = 0; tableIndex < image.tables.length; tableIndex++) {
      const table = image.tables[tableIndex];
      
      try {
        if (isRelevantTable(table)) {
          const extractedRows = extractTableData(table, imageIndex, tableIndex);
          
          if (extractedRows.length > 0) {
            extractedTables.push(extractedRows);
            console.log(`Successfully extracted ${extractedRows.length} rows from table ${tableIndex + 1} in image ${imageIndex + 1}`);
          } else {
            console.warn(`Table ${tableIndex + 1} in image ${imageIndex + 1} was identified as relevant but no data could be extracted`);
          }
        } else {
          console.log(`Table ${tableIndex + 1} in image ${imageIndex + 1} is not relevant (no required headers found)`);
        }
      } catch (error) {
        console.error(`Error processing table ${tableIndex + 1} in image ${imageIndex + 1}:`, error);
      }
    }
  }

  console.log(`Total extracted tables: ${extractedTables.length}`);
  return extractedTables;
}

// 관련 테이블인지 확인
function isRelevantTable(table: OCRTable): boolean {
  if (!table.cells || table.cells.length === 0) {
    return false;
  }

  // 첫 3행에서 헤더 찾기
  const headerCells = table.cells.filter(cell => cell.rowIndex <= 2);
  const headerTexts = headerCells
    .map(cell => getCellText(cell).toLowerCase())
    .filter(text => text.length > 0);

  console.log('Header texts found:', headerTexts);

  // 필수 키워드 확인
  const hasNo = headerTexts.some(text => 
    text.includes('no.') || 
    text === 'no' || 
    text.includes('번호') ||
    text.match(/^no\.?$/i)
  );
  
  const hasIdentification = headerTexts.some(text => 
    text.includes('identification') || 
    text.includes('식별') || 
    text.includes('ident') ||
    text.includes('id')
  );

  // 테이블 품질 확인
  const hasMinimumCells = table.cells.length >= 6; // 최소 헤더 + 데이터
  const hasReasonableConfidence = table.inferConfidence >= 0.5; // 신뢰도 기준 완화

  const isRelevant = hasNo && hasIdentification && hasMinimumCells && hasReasonableConfidence;
  
  console.log(`Table relevance check: hasNo=${hasNo}, hasIdentification=${hasIdentification}, minCells=${hasMinimumCells}, confidence=${hasReasonableConfidence} => ${isRelevant}`);
  
  return isRelevant;
}

// 테이블 데이터 추출
function extractTableData(table: OCRTable, imageIndex: number, tableIndex: number): ExtractedRow[] {
  console.log(`Processing table ${tableIndex + 1} in image ${imageIndex + 1}`);
  
  // 테이블 그리드 구축
  const tableGrid = buildTableGrid(table);
  
  if (tableGrid.length < 2) {
    console.warn('Table has less than 2 rows (need header + data)');
    return [];
  }

  console.log(`Table grid built: ${tableGrid.length} rows, ${tableGrid[0]?.length || 0} columns`);

  // 헤더 행 찾기
  const headerRowIndex = findHeaderRow(tableGrid);
  if (headerRowIndex === -1) {
    console.warn('No header row found');
    return [];
  }

  console.log(`Header row found at index: ${headerRowIndex}`);

  // 테이블 형식 결정
  const headerRow = tableGrid[headerRowIndex];
  const tableFormat = determineTableFormat(headerRow);
  console.log(`Table format detected: ${tableFormat}`);
  
  // 컬럼 매핑 찾기
  const columnMapping = findColumnMapping(headerRow, tableFormat);
  console.log('Column mapping:', columnMapping);
  
  // 데이터 행 추출
  const dataRows: ExtractedRow[] = [];
  
  for (let i = headerRowIndex + 1; i < tableGrid.length; i++) {
    const row = tableGrid[i];
    
    if (row && row.length > 0 && !isEmptyRow(row)) {
      try {
        const extractedRow = extractRowData(row, tableFormat, columnMapping, imageIndex, tableIndex, i);
        if (extractedRow && isValidRow(extractedRow)) {
          dataRows.push(extractedRow);
        }
      } catch (error) {
        console.warn(`Error processing row ${i}:`, error);
      }
    }
  }
  
  console.log(`Extracted ${dataRows.length} valid rows from table`);
  return dataRows;
}

// 테이블 그리드 구축
function buildTableGrid(table: OCRTable): string[][] {
  if (!table.cells || table.cells.length === 0) {
    return [];
  }

  const maxRow = Math.max(...table.cells.map(cell => cell.rowIndex + cell.rowSpan - 1)) + 1;
  const maxCol = Math.max(...table.cells.map(cell => cell.columnIndex + cell.columnSpan - 1)) + 1;
  
  const grid: string[][] = Array(maxRow).fill(null).map(() => Array(maxCol).fill(''));
  
  // 셀 내용으로 그리드 채우기
  table.cells.forEach(cell => {
    const text = getCellText(cell);
    
    for (let r = cell.rowIndex; r < cell.rowIndex + cell.rowSpan; r++) {
      for (let c = cell.columnIndex; c < cell.columnIndex + cell.columnSpan; c++) {
        if (grid[r] && grid[r][c] !== undefined) {
          // 기존 텍스트가 있으면 결합
          grid[r][c] = grid[r][c] ? `${grid[r][c]} ${text}`.trim() : text;
        }
      }
    }
  });
  
  return grid;
}

// 셀 텍스트 추출
function getCellText(cell: TableCell): string {
  if (!cell.cellTextLines || cell.cellTextLines.length === 0) {
    return '';
  }

  return cell.cellTextLines
    .map(line => 
      line.cellWords
        .map(word => word.inferText || '')
        .join(' ')
    )
    .join('\n')
    .trim();
}

// 헤더 행 찾기
function findHeaderRow(tableGrid: string[][]): number {
  for (let i = 0; i < Math.min(3, tableGrid.length); i++) {
    const row = tableGrid[i];
    const rowText = row.join(' ').toLowerCase();
    
    console.log(`Checking row ${i}: "${rowText}"`);
    
    const hasNo = rowText.includes('no.') || rowText.includes('번호') || /\bno\b/.test(rowText);
    const hasIdent = rowText.includes('identification') || rowText.includes('식별') || rowText.includes('ident');
    
    if (hasNo && hasIdent) {
      console.log(`Header row found at ${i}`);
      return i;
    }
  }
  return -1;
}

// 테이블 형식 결정
function determineTableFormat(headerRow: string[]): 'format1' | 'format2' {
  const headerText = headerRow.join(' ').toLowerCase();
  
  // Format 2: Tag No와 Joint No가 분리된 컬럼
  const hasTagNoColumn = headerText.includes('tag') && headerText.includes('no');
  const hasJointNoColumn = headerText.includes('joint') && headerText.includes('no');
  
  if (hasTagNoColumn && hasJointNoColumn) {
    return 'format2';
  }
  
  // Format 1: Identification No에 통합
  return 'format1';
}

// 컬럼 매핑 찾기
function findColumnMapping(headerRow: string[], format: 'format1' | 'format2'): ColumnMapping {
  const mapping: ColumnMapping = {
    no: -1,
    identification: -1,
    tagNo: -1,
    jointNo: -1,
    jointType: -1,
    weldingDate: -1
  };

  headerRow.forEach((header, index) => {
    const lowerHeader = header.toLowerCase().trim();
    
    console.log(`Column ${index}: "${header}" -> "${lowerHeader}"`);
    
    if ((lowerHeader.includes('no.') || lowerHeader === 'no') && 
        !lowerHeader.includes('identification') && 
        !lowerHeader.includes('tag') && 
        !lowerHeader.includes('joint')) {
      mapping.no = index;
      console.log(`  -> Mapped to 'no'`);
    } else if (lowerHeader.includes('identification') || lowerHeader.includes('ident')) {
      mapping.identification = index;
      console.log(`  -> Mapped to 'identification'`);
    } else if (lowerHeader.includes('tag') && lowerHeader.includes('no')) {
      mapping.tagNo = index;
      console.log(`  -> Mapped to 'tagNo'`);
    } else if (lowerHeader.includes('joint') && lowerHeader.includes('no')) {
      mapping.jointNo = index;
      console.log(`  -> Mapped to 'jointNo'`);
    } else if (lowerHeader.includes('joint') && lowerHeader.includes('type')) {
      mapping.jointType = index;
      console.log(`  -> Mapped to 'jointType'`);
    } else if (lowerHeader.includes('type') && !lowerHeader.includes('joint')) {
      mapping.jointType = index;
      console.log(`  -> Mapped to 'jointType'`);
    } else if (lowerHeader.includes('welding') || lowerHeader.includes('date')) {
      mapping.weldingDate = index;
      console.log(`  -> Mapped to 'weldingDate'`);
    }
  });

  console.log('Final column mapping:', mapping);
  return mapping;
}

// 행 데이터 추출
function extractRowData(
  row: string[], 
  format: 'format1' | 'format2', 
  columnMapping: ColumnMapping,
  imageIndex: number,
  tableIndex: number,
  rowIndex: number
): ExtractedRow | null {
  
  const extractedRow: ExtractedRow = {
    no: '',
    identificationNo: '',
    tagNo: '',
    jointNo: '',
    jointType: '',
    weldingDate: '',
    confidence: 0,
    sourceTable: tableIndex,
    sourceRow: rowIndex
  };

  console.log(`Processing row ${rowIndex}: [${row.map(cell => `"${cell}"`).join(', ')}]`);

  // No. 추출
  if (columnMapping.no >= 0 && columnMapping.no < row.length) {
    extractedRow.no = cleanText(row[columnMapping.no]);
  }

  if (format === 'format1') {
    // Format 1: 통합된 identification 데이터
    if (columnMapping.identification >= 0 && columnMapping.identification < row.length) {
      const combinedText = row[columnMapping.identification];
      const parsedData = parseIdentificationData(combinedText);
      extractedRow.identificationNo = parsedData.identificationNo;
      extractedRow.tagNo = parsedData.tagNo;
      extractedRow.jointNo = parsedData.jointNo;
      
      console.log(`  Parsed identification: "${combinedText}" -> `, parsedData);
    }
  } else {
    // Format 2: 분리된 컬럼들
    if (columnMapping.identification >= 0 && columnMapping.identification < row.length) {
      extractedRow.identificationNo = cleanText(row[columnMapping.identification]);
    }
    if (columnMapping.tagNo >= 0 && columnMapping.tagNo < row.length) {
      extractedRow.tagNo = cleanText(row[columnMapping.tagNo]);
    }
    if (columnMapping.jointNo >= 0 && columnMapping.jointNo < row.length) {
      extractedRow.jointNo = cleanText(row[columnMapping.jointNo]);
    }
  }

  // Joint Type 추출
  if (columnMapping.jointType >= 0 && columnMapping.jointType < row.length) {
    extractedRow.jointType = cleanText(row[columnMapping.jointType]);
  }

  // Welding Date 추출 (컬럼 매핑이 있으면 사용, 없으면 날짜 패턴으로 찾기)
  if (columnMapping.weldingDate >= 0 && columnMapping.weldingDate < row.length) {
    extractedRow.weldingDate = cleanText(row[columnMapping.weldingDate]);
  } else {
    const dateIndex = findDateColumn(row);
    if (dateIndex >= 0) {
      extractedRow.weldingDate = cleanText(row[dateIndex]);
    }
  }

  // 신뢰도 계산
  extractedRow.confidence = calculateRowConfidence(extractedRow);

  console.log(`  Extracted row:`, extractedRow);

  return extractedRow;
}

// Identification 데이터 파싱 (Format 1용)
function parseIdentificationData(combinedText: string): {
  identificationNo: string;
  tagNo: string;
  jointNo: string;
} {
  const cleanedText = cleanText(combinedText);
  
  console.log(`Parsing identification data: "${cleanedText}"`);
  
  // 줄바꿈으로 먼저 분리
  const lines = cleanedText.split(/[\r\n]+/).map(line => line.trim()).filter(line => line.length > 0);
  
  const allParts: string[] = [];
  lines.forEach(line => {
    // 공백과 특수문자로 분리
    const parts = line.split(/[\s\-_]+/).filter(part => part.length > 0);
    allParts.push(...parts);
  });

  console.log(`  Split into parts:`, allParts);

  if (allParts.length === 0) {
    return { identificationNo: cleanedText, tagNo: '', jointNo: '' };
  }

  if (allParts.length === 1) {
    return { identificationNo: allParts[0], tagNo: '', jointNo: '' };
  }

  // 길이별로 정렬하여 식별
  const sortedParts = [...allParts].sort((a, b) => b.length - a.length);
  
  const identificationNo = sortedParts[0]; // 가장 긴 것
  const jointNo = allParts.find(part => part.length <= 3 && /^[A-Z0-9]+$/i.test(part)) || 
                 sortedParts[sortedParts.length - 1]; // 3글자 이하 영숫자 또는 가장 짧은 것
  const tagNo = allParts.find(part => part !== identificationNo && part !== jointNo) || '';
  
  const result = { identificationNo, tagNo, jointNo };
  console.log(`  Parsed result:`, result);
  
  return result;
}

// 날짜 컬럼 찾기
function findDateColumn(row: string[]): number {
  const datePattern = /\d{4}[.\-\/]\d{1,2}[.\-\/]\d{1,2}/;
  
  for (let i = 0; i < row.length; i++) {
    if (datePattern.test(row[i])) {
      console.log(`  Found date in column ${i}: "${row[i]}"`);
      return i;
    }
  }
  
  return -1;
}

// 텍스트 정리
function cleanText(text: string): string {
  return text
    .replace(/[\r\n\t]+/g, ' ')
    .replace(/\s+/g, ' ')
    .trim();
}

// 빈 행 확인
function isEmptyRow(row: string[]): boolean {
  return row.every(cell => !cell || cell.trim().length === 0);
}

// 유효한 행 확인
function isValidRow(row: ExtractedRow): boolean {
  // 번호나 식별번호 중 하나라도 있으면 유효
  const hasBasicData = !!(row.no || row.identificationNo);
  
  // 너무 짧은 데이터는 제외 (오인식 방지)
  const hasReasonableLength = (row.identificationNo?.length || 0) >= 3 || 
                             (row.no?.length || 0) >= 1;
  
  return hasBasicData && hasReasonableLength;
}

// 행 신뢰도 계산
function calculateRowConfidence(row: ExtractedRow): number {
  let score = 0;
  let maxScore = 0;

  // 각 필드별 가중치
  const weights = {
    no: 1,
    identificationNo: 3, // 가장 중요
    tagNo: 2,
    jointNo: 2,
    jointType: 1,
    weldingDate: 1
  };

  Object.entries(weights).forEach(([field, weight]) => {
    maxScore += weight;
    const value = row[field as keyof ExtractedRow] as string;
    
    if (value && value.length > 0) {
      // 기본 점수
      score += weight * 0.5;
      
      // 길이 보너스
      if (field === 'identificationNo' && value.length > 10) {
        score += weight * 0.3;
      } else if (field === 'no' && /^\d+$/.test(value)) {
        score += weight * 0.3;
      } else if (field === 'weldingDate' && /\d{4}[.\-\/]\d{1,2}[.\-\/]\d{1,2}/.test(value)) {
        score += weight * 0.3;
      } else if (value.length > 2) {
        score += weight * 0.2;
      }
    }
  });

  return maxScore > 0 ? Math.min(score / maxScore, 1) : 0;
}

// 유틸리티: OCR 결과 품질 분석
export function analyzeOCRQuality(ocrResult: any): { 
  confidence: number; 
  tablesFound: number; 
  textQuality: number;
  keywordCount: number;
} {
  let totalConfidence = 0;
  let totalFields = 0;
  let tablesFound = 0;
  let relevantKeywords = 0;

  const keywords = ['no.', 'identification', 'joint', 'tag', 'type', 'weld', 'date'];

  if (ocrResult.images) {
    ocrResult.images.forEach((image: any) => {
      // 테이블 분석
      if (image.tables) {
        tablesFound += image.tables.length;
      }

      // 필드 신뢰도 분석
      if (image.fields) {
        image.fields.forEach((field: any) => {
          const confidence = field.inferConfidence || 0;
          const text = (field.inferText || '').toLowerCase();
          
          totalConfidence += confidence;
          totalFields++;

          // 관련 키워드 확인
          keywords.forEach(keyword => {
            if (text.includes(keyword)) {
              relevantKeywords++;
            }
          });
        });
      }
    });
  }

  const avgConfidence = totalFields > 0 ? totalConfidence / totalFields : 0;
  const textQuality = totalFields > 0 ? relevantKeywords / totalFields : 0;

  return {
    confidence: avgConfidence,
    tablesFound,
    textQuality,
    keywordCount: relevantKeywords
  };
}