// igv_custom.js
// IGV 브라우저가 생성된 후, 파란색 라인 2개를 ideogram/viewport에 추가하고 드래그로 이동 가능하게 함
// 라인 위치 변경 시 window에 커스텀 이벤트('igv-blue-lines-changed')를 dispatch

(function() {
  // 설정값
  const LINE_COLOR = '#007bff';
  const LINE_WIDTH = 2;
  const INIT_RATIO_1 = 0.3; // 30% 위치
  const INIT_RATIO_2 = 0.7; // 70% 위치

  // 내부 상태
  let viewportRect = null;
  let dragging = null; // 'start' or 'end' or null
  let dragOffset = 0;
  let startRatio = INIT_RATIO_1;
  let endRatio = INIT_RATIO_2;

  // 라인 DOM
  let viewportLines = [];
  let viewportFill = null;
  let ideogramLines = [];
  let ideogramFill = null;

  // IGV가 준비되면 실행
  function waitForIGVAndInit() {
    const check = () => {
      const viewport = document.querySelector('.igv-viewport-content');
      if (viewport) {
        setupLines();
      } else {
        setTimeout(check, 300);
      }
    };
    check();
  }

  // 라인 생성 및 이벤트 바인딩
  function setupLines() {
    // 모든 파란 라인 삭제
    document.querySelectorAll('.igv-blue-line').forEach(el => el.remove());
    // 기존 fill 오버레이 삭제
    document.querySelectorAll('.igv-blue-fill').forEach(el => el.remove());

    // 모든 .igv-viewport-content 중, height가 16px 초과인 첫 번째를 메인 뷰포트로 간주
    const viewports = Array.from(document.querySelectorAll('.igv-viewport-content'));
    const mainViewport = viewports.find(vp => {
      const h = vp.offsetHeight || parseInt(vp.style.height, 10);
      return h > 16;
    });
    if (!mainViewport) return;

    // 이미 있으면 중복 생성 방지
    if (mainViewport.parentNode.querySelector('.igv-blue-line')) return;

    viewportRect = mainViewport.getBoundingClientRect();

    // 라인 2개 생성 (뷰포트)
    viewportLines = [createLine('start', 'viewport', mainViewport), createLine('end', 'viewport', mainViewport)];
    viewportLines.forEach(line => mainViewport.parentNode.appendChild(line));
    // fill 오버레이 생성 및 추가 (뷰포트)
    viewportFill = document.createElement('div');
    viewportFill.className = 'igv-blue-fill';
    Object.assign(viewportFill.style, {
      position: 'absolute',
      top: (viewportRect.top - mainViewport.getBoundingClientRect().top) + 'px',
      height: viewportRect.height + 'px',
      background: 'rgba(0,123,255,0.18)',
      zIndex: 999,
      pointerEvents: 'none',
      borderRadius: '2px',
      transition: 'left 0.08s, width 0.08s',
    });
    mainViewport.parentNode.appendChild(viewportFill);

    // === ideogram(미니맵)에도 라인/오버레이 추가 ===
    const ideogram = document.querySelector('.igv-ideogram-content') || document.querySelector('.igv-ideogram');
    if (ideogram) {
      const ideogramRect = ideogram.getBoundingClientRect();
      ideogramLines = [createLine('start', 'ideogram', ideogram), createLine('end', 'ideogram', ideogram)];
      ideogramLines.forEach(line => ideogram.parentNode.appendChild(line));
      ideogramFill = document.createElement('div');
      ideogramFill.className = 'igv-blue-fill';
      Object.assign(ideogramFill.style, {
        position: 'absolute',
        top: (ideogramRect.top - ideogram.parentNode.getBoundingClientRect().top) + 'px',
        height: ideogramRect.height + 'px',
        background: 'rgba(0,123,255,0.18)',
        zIndex: 999,
        pointerEvents: 'none',
        borderRadius: '2px',
        transition: 'left 0.08s, width 0.08s',
      });
      ideogram.parentNode.appendChild(ideogramFill);
    }

    updateLinePositions();
    bindDragEvents();
  }

  // 라인 DOM 생성
  function createLine(which, area, parentEl) {
    const line = document.createElement('div');
    line.className = 'igv-blue-line';
    line.dataset.which = which;
    line.dataset.area = area;
    line._parentEl = parentEl; // 커스텀 속성으로 부모 저장
    Object.assign(line.style, {
      position: 'absolute',
      top: area === 'ideogram' ? (viewportRect.top - parentEl.getBoundingClientRect().top) + 'px' : (viewportRect.top - parentEl.getBoundingClientRect().top) + 'px',
      width: LINE_WIDTH + 'px',
      height: area === 'ideogram' ? viewportRect.height + 'px' : viewportRect.height + 'px',
      background: LINE_COLOR,
      zIndex: 1000,
      cursor: 'ew-resize',
      userSelect: 'none',
    });
    line.addEventListener('mousedown', (e) => startDrag(which, e));
    return line;
  }

  // 라인 위치 갱신
  function updateLinePositions() {
    viewportRect = document.querySelector('.igv-viewport-content').getBoundingClientRect();
    let baseArea = document.querySelector('.igv-viewport-content canvas, .igv-viewport-content svg');
    let baseRect = baseArea ? baseArea.getBoundingClientRect() : viewportRect;
    // viewport 라인 위치 (실제 베이스 표시 영역 기준)
    const baseWidth = baseRect.width;
    const baseLeft = baseRect.left;
    const startX_view = baseLeft + baseWidth * startRatio;
    const endX_view = baseLeft + baseWidth * endRatio;
    viewportLines[0].style.left = (startX_view - viewportLines[0]._parentEl.getBoundingClientRect().left) + 'px';
    viewportLines[1].style.left = (endX_view - viewportLines[1]._parentEl.getBoundingClientRect().left) + 'px';
    // fill 오버레이 위치/크기 갱신
    if (viewportFill) {
      const left = Math.min(startX_view, endX_view) - viewportFill.parentNode.getBoundingClientRect().left;
      const width = Math.abs(endX_view - startX_view);
      viewportFill.style.left = left + 'px';
      viewportFill.style.width = width + 'px';
    }
    // === ideogram(미니맵) 라인/오버레이 위치 갱신 ===
    const ideogram = document.querySelector('.igv-ideogram-content') || document.querySelector('.igv-ideogram');
    if (ideogram && ideogramLines.length === 2 && ideogramFill) {
      const ideogramRect = ideogram.getBoundingClientRect();
      const ideogramWidth = ideogramRect.width;
      const ideogramLeft = ideogramRect.left;
      const startX_ideo = ideogramLeft + ideogramWidth * startRatio;
      const endX_ideo = ideogramLeft + ideogramWidth * endRatio;
      ideogramLines[0].style.left = (startX_ideo - ideogram.parentNode.getBoundingClientRect().left) + 'px';
      ideogramLines[1].style.left = (endX_ideo - ideogram.parentNode.getBoundingClientRect().left) + 'px';
      // fill
      const left = Math.min(startX_ideo, endX_ideo) - ideogramFill.parentNode.getBoundingClientRect().left;
      const width = Math.abs(endX_ideo - startX_ideo);
      ideogramFill.style.left = left + 'px';
      ideogramFill.style.width = width + 'px';
    }
  }

  // 드래그 이벤트 바인딩
  function bindDragEvents() {
    document.addEventListener('mousemove', onDrag);
    document.addEventListener('mouseup', stopDrag);
  }

  function startDrag(which, e) {
    dragging = which;
    dragOffset = e.clientX;
    e.preventDefault();
    e.stopPropagation();
  }

  function onDrag(e) {
    if (!dragging) return;
    const areaWidth = viewportRect.width;
    let x = e.clientX - viewportRect.left;
    let ratio = x / areaWidth;
    ratio = Math.max(0, Math.min(1, ratio));
    if (dragging === 'start') {
      startRatio = Math.min(ratio, endRatio - 0.01);
    } else {
      endRatio = Math.max(ratio, startRatio + 0.01);
    }
    updateLinePositions();
    fireChangeEvent();
  }

  function stopDrag() {
    dragging = null;
  }

  // 라인 위치 변경 이벤트 발생
  function fireChangeEvent() {
    console.log('fireChangeEvent 호출됨', { startRatio, endRatio });
    window.dispatchEvent(new CustomEvent('igv-blue-lines-changed', {
      detail: {
        startRatio,
        endRatio
      }
    }));
  }

  // 외부에서 라인 위치를 강제로 지정할 수 있도록 export
  window.igvCustom = {
    setLineRatios: (start, end) => {
      startRatio = start;
      endRatio = end;
      updateLinePositions();
      fireChangeEvent();
    },
    getLineRatios: () => ({ startRatio, endRatio }),
    setupLines: setupLines
  };

  // 스타일 추가
  const style = document.createElement('style');
  style.innerHTML = `.igv-blue-line { pointer-events: auto !important; }
  .igv-blue-fill { pointer-events: none !important; }`;
  document.head.appendChild(style);

  // IGV가 준비되면 실행
  setTimeout(waitForIGVAndInit, 1000);
})();