{% extends 'base.html' %}

{% block title %}Face Blur — 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">Face Blur</li>
    </ol>
  </nav>

  <!-- Page Header -->
  <div class="row mb-4">
    <div class="col">
      <h1 class="h2 fw-bold"><i class="fa-solid fa-user-secret me-2 text-primary"></i>Face Blur</h1>
      <p class="text-muted">Automatically detect and blur faces in photos to protect privacy.</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">

          <!-- OpenCV notice -->
          <div class="alert alert-info mb-4">
            <i class="fa-solid fa-circle-info me-2"></i>
            <strong>Automatic Detection:</strong> Uses OpenCV's Haar Cascade classifier for face detection.
            Accuracy varies with image quality and lighting conditions.
          </div>

          <!-- 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="previewName" class="small text-muted mt-2 mb-0"></p>
          </div>

          <!-- Blur strength -->
          <div class="mb-4">
            <label class="form-label fw-semibold">Blur Strength</label>
            <div class="row g-3">
              <div class="col-4">
                <input type="radio" class="btn-check" name="blur_strength" id="blurLight" value="light">
                <label class="btn btn-outline-secondary w-100 py-3" for="blurLight">
                  <i class="fa-solid fa-droplet d-block mb-1"></i>
                  <strong>Light</strong>
                  <small class="d-block text-muted">Subtle blur</small>
                </label>
              </div>
              <div class="col-4">
                <input type="radio" class="btn-check" name="blur_strength" id="blurMedium" value="medium" checked>
                <label class="btn btn-outline-secondary w-100 py-3" for="blurMedium">
                  <i class="fa-solid fa-droplet d-block mb-1 fa-lg"></i>
                  <strong>Medium</strong>
                  <small class="d-block text-muted">Recommended</small>
                </label>
              </div>
              <div class="col-4">
                <input type="radio" class="btn-check" name="blur_strength" id="blurHeavy" value="heavy">
                <label class="btn btn-outline-secondary w-100 py-3" for="blurHeavy">
                  <i class="fa-solid fa-droplet d-block mb-1 fa-2x"></i>
                  <strong>Heavy</strong>
                  <small class="d-block text-muted">Maximum blur</small>
                </label>
              </div>
            </div>
          </div>

          <!-- Submit -->
          <div class="d-grid">
            <button id="submitBtn" type="button" class="btn btn-primary btn-lg" disabled>
              <i class="fa-solid fa-user-secret me-2"></i>Blur Faces
            </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">Detecting and blurring faces…</p>
          <p class="small text-muted">Running face detection on the 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>Face Blur Complete
        </div>
        <div class="card-body p-4">
          <!-- Detection count badge -->
          <div id="faceCountWrap" class="mb-4">
            <div class="d-flex align-items-center gap-3 p-3 rounded bg-light">
              <i class="fa-solid fa-users fa-2x text-primary"></i>
              <div>
                <p class="mb-0 fw-semibold">Faces Detected &amp; Blurred</p>
                <p class="mb-0 h3 text-primary"><span id="faceCount">0</span></p>
              </div>
            </div>
          </div>
          <div id="noFacesAlert" class="alert alert-warning d-none mb-4">
            <i class="fa-solid fa-triangle-exclamation me-2"></i>
            No faces were detected in this image. The image is returned unchanged.
          </div>
          <div class="text-center mb-4">
            <img id="resultPreview" src="" alt="Blurred image" class="img-fluid rounded shadow-sm" style="max-height:280px;">
          </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 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-user-secret fa-3x mb-3 opacity-25"></i>
          <p class="mb-0">Upload a photo and faces will be automatically detected and blurred.</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 previewName = document.getElementById('previewName');
  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');

  let selectedFile = null;

  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;
    previewName.textContent = file.name;
    const reader = new FileReader();
    reader.onload = (e) => {
      document.getElementById('imagePreview').src = e.target.result;
      previewWrap.classList.remove('d-none');
    };
    reader.readAsDataURL(file);
    submitBtn.disabled = false;
    hideResults();
  }

  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('blur_strength', document.querySelector('input[name="blur_strength"]:checked').value);

    try {
      const resp = await fetch('/tools/image/face-blur/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 faceCount = parseInt(resp.headers.get('X-Faces-Detected') || '0');
      document.getElementById('faceCount').textContent = faceCount;

      const noFacesAlert = document.getElementById('noFacesAlert');
      if (faceCount === 0) {
        noFacesAlert.classList.remove('d-none');
        document.getElementById('faceCountWrap').classList.add('d-none');
      } else {
        noFacesAlert.classList.add('d-none');
        document.getElementById('faceCountWrap').classList.remove('d-none');
      }

      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 = 'blurred_' + 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 %}