// app/api/ocr/utils/tableExtraction.ts
// 개선된 완전 테이블 추출 로직 – Format‑1 식별번호 파싱 보강 & 중복 행 제거

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/* 타입                                                                   */
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export 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;
}

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/* 메인                                                                   */
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export async function extractTablesFromOCR (ocrResult: any): Promise<ExtractedRow[][]> {
  const tables: ExtractedRow[][] = [];
  if (!ocrResult?.images) return tables;

  ocrResult.images.forEach((image: any, imgIdx: number) => {
    image.tables?.forEach((table: OCRTable, tblIdx: number) => {
      if (!isRelevantTable(table)) return;
      const rows = extractTableData(table, imgIdx, tblIdx);
      if (rows.length) tables.push(rows);
    });
  });
  return tables;
}

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/* 관련 테이블 판별                                                       */
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function isRelevantTable (table: OCRTable): boolean {
  const headers = table.cells.filter(c => c.rowIndex < 3).map(getCellText).join(' ').toLowerCase();
  return /\bno\b|번호/.test(headers) && /identification|식별|ident|id/.test(headers);
}

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/* 표 해석                                                                 */
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function extractTableData (table: OCRTable, imgIdx: number, tblIdx: number): ExtractedRow[] {
  const grid = buildGrid(table);
  const headerRowIdx = findHeaderRow(grid);
  if (headerRowIdx === -1) return [];

  const format   = detectFormat(grid[headerRowIdx]);
  const mapping  = mapColumns(grid[headerRowIdx]);

  const seen = new Set<string>();
  const data: ExtractedRow[] = [];

  for (let r = headerRowIdx + 1; r < grid.length; r++) {
    const row = grid[r];
    if (isBlankRow(row)) continue;

    const parsed = buildRow(row, format, mapping, tblIdx, r);
    if (!parsed || !isValidRow(parsed)) continue;

    const key = `${parsed.no}-${parsed.identificationNo}`;
    if (seen.has(key)) continue;
    seen.add(key);

    data.push(parsed);
  }
  return data;
}

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/* Grid & Header                                                             */
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function buildGrid (table: OCRTable): string[][] {
  const maxR = Math.max(...table.cells.map(c => c.rowIndex + c.rowSpan - 1));
  const maxC = Math.max(...table.cells.map(c => c.columnIndex + c.columnSpan - 1));
  const grid = Array.from({ length: maxR + 1 }, () => Array(maxC + 1).fill(''));

  table.cells.forEach(cell => {
    const txt = getCellText(cell);
    for (let r = cell.rowIndex; r < cell.rowIndex + cell.rowSpan; r++) {
      for (let c = cell.columnIndex; c < cell.columnIndex + cell.columnSpan; c++) {
        grid[r][c] = grid[r][c] ? `${grid[r][c]} ${txt}` : txt;
      }
    }
  });
  return grid;
}

function getCellText (cell: TableCell): string {
  return cell.cellTextLines?.flatMap(l => l.cellWords.map(w => w.inferText.trim())).filter(Boolean).join(' ') ?? '';
}

function findHeaderRow (grid: string[][]): number {
  for (let i = 0; i < Math.min(3, grid.length); i++) {
    const t = grid[i].join(' ').toLowerCase();
    if (/\bno\b|번호/.test(t) && /identification|식별|ident/.test(t)) return i;
  }
  return -1;
}

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/* Column Mapping                                                            */
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function detectFormat (header: string[]): 'format1' | 'format2' {
  const h = header.join(' ').toLowerCase();
  return h.includes('tag') && h.includes('joint') ? 'format2' : 'format1';
}

function mapColumns (header: string[]): ColumnMapping {
  const mp: ColumnMapping = { no: -1, identification: -1, tagNo: -1, jointNo: -1, jointType: -1, weldingDate: -1 };

  header.forEach((h, i) => {
    const t = h.toLowerCase();
    if (/^no\.?$/.test(t) && !/ident|tag|joint/.test(t)) mp.no = i;
    else if (/identification|ident/.test(t)) mp.identification = i;
    else if (/tag.*no/.test(t)) mp.tagNo = i;
    else if (/joint.*no/.test(t)) mp.jointNo = i;
    else if (/joint.*type/.test(t) || (/^type$/.test(t) && mp.jointType === -1)) mp.jointType = i;
    else if (/welding|date/.test(t)) mp.weldingDate = i;
  });
  return mp;
}

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/* Row Extraction                                                            */
/* -------------------------------------------------------------------------- */

function buildRow (
  row: string[],
  format: 'format1' | 'format2',
  mp: ColumnMapping,
  tblIdx: number,
  rowIdx: number
): ExtractedRow | null {
  const out: ExtractedRow = {
    no: mp.no >= 0 ? clean(row[mp.no]) : '',
    identificationNo: '',
    tagNo: '',
    jointNo: '',
    jointType: mp.jointType >= 0 ? clean(row[mp.jointType]) : '',
    weldingDate: '',
    confidence: 0,
    sourceTable: tblIdx,
    sourceRow: rowIdx,
  };

  if (mp.weldingDate >= 0) out.weldingDate = clean(row[mp.weldingDate]);
  else {
    const idx = row.findIndex(col => /\d{4}[.\-/]\d{1,2}[.\-/]\d{1,2}/.test(col));
    if (idx >= 0) out.weldingDate = clean(row[idx]);
  }

  if (format === 'format2') {
    if (mp.identification >= 0) out.identificationNo = clean(row[mp.identification]);
    if (mp.jointNo >= 0) out.jointNo = clean(row[mp.jointNo]);
    if (mp.tagNo >= 0) out.tagNo = clean(row[mp.tagNo]);
  } else {
    const combined = mp.identification >= 0 ? row[mp.identification] : '';
    const parsed = parseIdentificationData(combined);
    out.identificationNo = parsed.identificationNo;
    out.jointNo         = parsed.jointNo;
    out.tagNo           = parsed.tagNo;
  }

  out.confidence = scoreRow(out);
  return out;
}

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/* Format‑1 셀 파싱                                                         */
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function parseIdentificationData (txt: string): { identificationNo: string; jointNo: string; tagNo: string } {
  const cleaned = clean(txt);
  if (!cleaned) return { identificationNo: '', jointNo: '', tagNo: '' };

  const tokens = cleaned.split(/\s+/).map(clean).filter(Boolean);

  // Identification 후보: 하이픈이 2개 이상 포함된 토큰 가운데 가장 긴 것
  const idCand = tokens.filter(t => t.split('-').length >= 3).sort((a, b) => b.length - a.length);
  const identificationNo = idCand[0] || '';

  const residual = tokens.filter(t => t !== identificationNo);
  if (!residual.length) return { identificationNo, jointNo: '', tagNo: '' };

  residual.sort((a, b) => a.length - b.length);
  const jointNo = residual[0] || '';
  const tagNo   = residual[residual.length - 1] || '';

  return { identificationNo, jointNo, tagNo };
}

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/* Helpers                                                                   */
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const clean = (s: string = '') => s.replace(/[\r\n\t]+/g, ' ').replace(/\s+/g, ' ').trim();
const isBlankRow = (row: string[]) => row.every(c => !clean(c));
const isValidRow = (r: ExtractedRow) => !!(r.no || r.identificationNo);

function scoreRow (r: ExtractedRow): number {
  const w: Record<keyof ExtractedRow, number> = {
    no: 1, identificationNo: 3, tagNo: 2, jointNo: 2, jointType: 1, weldingDate: 1,
    confidence: 0, sourceTable: 0, sourceRow: 0,
  } as any;
  let s = 0, t = 0;
  (Object.keys(w) as (keyof ExtractedRow)[]).forEach(k => { t += w[k]; if ((r[k] as string)?.length) s += w[k]; });
  return t ? s / t : 0;
}

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/* OCR 품질 분석 (기존 로직 유지)                                            */
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export function analyzeOCRQuality (ocrResult: any) {
  let conf = 0, cnt = 0, tbl = 0, kw = 0;
  const keys = ['no.', 'identification', 'joint', 'tag', 'type', 'weld', 'date'];

  ocrResult.images?.forEach((img: any) => {
    tbl += img.tables?.length || 0;
    img.fields?.forEach((f: any) => {
      conf += f.inferConfidence || 0; cnt++;
      const t = (f.inferText || '').toLowerCase();
      keys.forEach(k => { if (t.includes(k)) kw++; });
    });
  });

  return { confidence: cnt ? conf / cnt : 0, tablesFound: tbl, textQuality: cnt ? kw / cnt : 0, keywordCount: kw };
}