{% extends 'base.html' %}

{% block title %}Crop Image — WebTools{% endblock %}

{% block content %}
<div class="container py-5">

  <!-- Breadcrumb -->
  <nav aria-label="breadcrumb" class="mb-4">
    <ol class="breadcrumb">
      <li class="breadcrumb-item"><a href="{{ url_for('main.index') }}">Home</a></li>
      <li class="breadcrumb-item"><a href="{{ url_for('main.index') }}#image">Image Tools</a></li>
      <li class="breadcrumb-item active" aria-current="page">Crop Image</li>
    </ol>
  </nav>

  <!-- Page Header -->
  <div class="row mb-4">
    <div class="col">
      <h1 class="h2 fw-bold"><i class="fa-solid fa-crop-simple me-2 text-primary"></i>Crop Image</h1>
      <p class="text-muted">Crop your image by specifying pixel coordinates or select a preset aspect ratio.</p>
    </div>
  </div>

  <div class="row g-4">
    <!-- Left column: form -->
    <div class="col-lg-6">
      <div class="card shadow-sm border-0">
        <div class="card-body p-4">

          <!-- Drop zone -->
          <div id="dropZone" class="border border-2 rounded-3 text-center p-5 mb-4 position-relative"
               style="border-style:dashed!important;cursor:pointer;transition:background .2s;">
            <i class="fa-solid fa-cloud-arrow-up fa-2x text-muted mb-2"></i>
            <p class="mb-1 fw-semibold">Drag &amp; drop an image here</p>
            <p class="text-muted small mb-3">or click to browse</p>
            <input type="file" id="imageInput" name="image" accept="image/*"
                   class="position-absolute top-0 start-0 w-100 h-100 opacity-0" style="cursor:pointer;">
          </div>

          <!-- Preview -->
          <div id="previewWrap" class="mb-4 d-none text-center">
            <img id="imagePreview" src="" alt="Preview" class="img-fluid rounded shadow-sm" style="max-height:180px;">
            <p id="previewInfo" class="small text-muted mt-2 mb-0"></p>
          </div>

          <!-- Preset aspect ratios -->
          <div class="mb-4">
            <label class="form-label fw-semibold">Preset Aspect Ratio</label>
            <div class="btn-group w-100 flex-wrap" role="group">
              <input type="radio" class="btn-check" name="aspectPreset" id="presetFree" value="free" checked>
              <label class="btn btn-outline-secondary" for="presetFree">Free</label>
              <input type="radio" class="btn-check" name="aspectPreset" id="preset11" value="1:1">
              <label class="btn btn-outline-secondary" for="preset11">1:1</label>
              <input type="radio" class="btn-check" name="aspectPreset" id="preset43" value="4:3">
              <label class="btn btn-outline-secondary" for="preset43">4:3</label>
              <input type="radio" class="btn-check" name="aspectPreset" id="preset169" value="16:9">
              <label class="btn btn-outline-secondary" for="preset169">16:9</label>
            </div>
            <p id="presetHint" class="small text-muted mt-1 mb-0 d-none">
              <i class="fa-solid fa-circle-info me-1"></i>
              <span id="presetHintText"></span>
            </p>
          </div>

          <!-- Crop coordinates -->
          <div class="mb-4">
            <label class="form-label fw-semibold">Crop Coordinates (pixels)</label>
            <div class="row g-3">
              <div class="col-6">
                <label for="cropLeft" class="form-label small text-muted">Left (X1)</label>
                <input type="number" class="form-control" id="cropLeft" name="left" min="0" value="0" placeholder="0">
              </div>
              <div class="col-6">
                <label for="cropTop" class="form-label small text-muted">Top (Y1)</label>
                <input type="number" class="form-control" id="cropTop" name="top" min="0" value="0" placeholder="0">
              </div>
              <div class="col-6">
                <label for="cropRight" class="form-label small text-muted">Right (X2)</label>
                <input type="number" class="form-control" id="cropRight" name="right" min="1" placeholder="Width">
              </div>
              <div class="col-6">
                <label for="cropBottom" class="form-label small text-muted">Bottom (Y2)</label>
                <input type="number" class="form-control" id="cropBottom" name="bottom" min="1" placeholder="Height">
              </div>
            </div>
            <p class="small text-muted mt-2 mb-0">
              <i class="fa-solid fa-circle-info me-1"></i>Coordinates are from the top-left corner of the image.
            </p>
          </div>

          <!-- Submit -->
          <div class="d-grid">
            <button id="submitBtn" type="button" class="btn btn-primary btn-lg" disabled>
              <i class="fa-solid fa-crop-simple me-2"></i>Crop Image
            </button>
          </div>

        </div>
      </div>
    </div>

    <!-- Right column: results -->
    <div class="col-lg-6">
      <div id="errorAlert" class="alert alert-danger d-none" role="alert">
        <i class="fa-solid fa-circle-xmark me-2"></i><span id="errorMsg"></span>
      </div>

      <div id="loadingCard" class="card shadow-sm border-0 d-none">
        <div class="card-body p-5 text-center">
          <div class="spinner-border text-primary mb-3" style="width:3rem;height:3rem;" role="status">
            <span class="visually-hidden">Processing...</span>
          </div>
          <p class="fw-semibold mb-0">Cropping image…</p>
        </div>
      </div>

      <div id="resultsCard" class="card shadow-sm border-0 d-none">
        <div class="card-header bg-success text-white fw-semibold">
          <i class="fa-solid fa-circle-check me-2"></i>Crop Complete
        </div>
        <div class="card-body p-4">
          <div class="text-center mb-4">
            <img id="resultPreview" src="" alt="Cropped image" class="img-fluid rounded shadow-sm" style="max-height:220px;">
          </div>
          <div class="d-grid">
            <a id="downloadLink" href="#" class="btn btn-success btn-lg" download>
              <i class="fa-solid fa-download me-2"></i>Download Cropped Image
            </a>
          </div>
        </div>
      </div>

      <div id="placeholderCard" class="card border-0 bg-light">
        <div class="card-body p-5 text-center text-muted">
          <i class="fa-solid fa-crop-simple fa-3x mb-3 opacity-25"></i>
          <p class="mb-0">Your cropped image will appear here after processing.</p>
        </div>
      </div>
    </div>
  </div>
</div>
{% endblock %}

{% block scripts %}
<script>
(function () {
  'use strict';

  const dropZone    = document.getElementById('dropZone');
  const fileInput   = document.getElementById('imageInput');
  const previewWrap = document.getElementById('previewWrap');
  const previewInfo = document.getElementById('previewInfo');
  const submitBtn   = document.getElementById('submitBtn');
  const errorAlert  = document.getElementById('errorAlert');
  const errorMsg    = document.getElementById('errorMsg');
  const loadingCard = document.getElementById('loadingCard');
  const resultsCard = document.getElementById('resultsCard');
  const placeholder = document.getElementById('placeholderCard');
  const cropRight   = document.getElementById('cropRight');
  const cropBottom  = document.getElementById('cropBottom');
  const presetHint  = document.getElementById('presetHint');
  const presetHintTxt = document.getElementById('presetHintText');

  let selectedFile = null;
  let imgW = 0, imgH = 0;

  dropZone.addEventListener('dragover', (e) => { e.preventDefault(); dropZone.classList.add('bg-primary','bg-opacity-10'); });
  dropZone.addEventListener('dragleave', () => { dropZone.classList.remove('bg-primary','bg-opacity-10'); });
  dropZone.addEventListener('drop', (e) => {
    e.preventDefault();
    dropZone.classList.remove('bg-primary','bg-opacity-10');
    if (e.dataTransfer.files[0]) handleFile(e.dataTransfer.files[0]);
  });
  fileInput.addEventListener('change', () => { if (fileInput.files[0]) handleFile(fileInput.files[0]); });

  function handleFile(file) {
    selectedFile = file;
    const reader = new FileReader();
    reader.onload = (ev) => {
      const img = document.getElementById('imagePreview');
      img.src = ev.target.result;
      img.onload = () => {
        imgW = img.naturalWidth;
        imgH = img.naturalHeight;
        previewInfo.textContent = file.name + ' — ' + imgW + ' × ' + imgH + 'px';
        cropRight.value  = imgW;
        cropRight.max    = imgW;
        cropBottom.value = imgH;
        cropBottom.max   = imgH;
        document.getElementById('cropLeft').max = imgW - 1;
        document.getElementById('cropTop').max  = imgH - 1;
      };
      previewWrap.classList.remove('d-none');
    };
    reader.readAsDataURL(file);
    submitBtn.disabled = false;
    hideResults();
  }

  // Preset aspect ratio logic
  document.querySelectorAll('input[name="aspectPreset"]').forEach(r => {
    r.addEventListener('change', () => {
      if (r.value === 'free' || !imgW) {
        presetHint.classList.add('d-none');
        return;
      }
      const [rw, rh] = r.value.split(':').map(Number);
      // Compute crop box centred on image
      let cw, ch;
      if (imgW / imgH > rw / rh) {
        ch = imgH;
        cw = Math.round(ch * rw / rh);
      } else {
        cw = imgW;
        ch = Math.round(cw * rh / rw);
      }
      const left = Math.round((imgW - cw) / 2);
      const top  = Math.round((imgH - ch) / 2);
      document.getElementById('cropLeft').value   = left;
      document.getElementById('cropTop').value    = top;
      document.getElementById('cropRight').value  = left + cw;
      document.getElementById('cropBottom').value = top  + ch;
      presetHintTxt.textContent = 'Crop area auto-set for ' + r.value + ' ratio (' + cw + '×' + ch + 'px).';
      presetHint.classList.remove('d-none');
    });
  });

  function hideResults() {
    errorAlert.classList.add('d-none');
    loadingCard.classList.add('d-none');
    resultsCard.classList.add('d-none');
    placeholder.classList.remove('d-none');
  }

  submitBtn.addEventListener('click', async () => {
    if (!selectedFile) return;
    errorAlert.classList.add('d-none');
    loadingCard.classList.remove('d-none');
    resultsCard.classList.add('d-none');
    placeholder.classList.add('d-none');
    submitBtn.disabled = true;

    const fd = new FormData();
    fd.append('image', selectedFile);
    fd.append('left',   document.getElementById('cropLeft').value);
    fd.append('top',    document.getElementById('cropTop').value);
    fd.append('right',  document.getElementById('cropRight').value);
    fd.append('bottom', document.getElementById('cropBottom').value);

    try {
      const resp = await fetch('/tools/image/crop/process', { method: 'POST', body: fd });
      if (!resp.ok) {
        let msg = 'Server error ' + resp.status;
        try { const j = await resp.json(); msg = j.error || msg; } catch(_) {}
        throw new Error(msg);
      }
      const blob = await resp.blob();
      const url  = URL.createObjectURL(blob);
      document.getElementById('resultPreview').src = url;
      const dl = document.getElementById('downloadLink');
      dl.href     = url;
      dl.download = 'cropped_' + selectedFile.name;
      loadingCard.classList.add('d-none');
      resultsCard.classList.remove('d-none');
    } catch (err) {
      loadingCard.classList.add('d-none');
      placeholder.classList.remove('d-none');
      errorMsg.textContent = err.message;
      errorAlert.classList.remove('d-none');
    } finally {
      submitBtn.disabled = false;
    }
  });
})();
</script>
{% endblock %}