/* ============================================
   GrubFlip — Post Meal Form
   Image upload, dietary tag picker, meal
   creation with preview.
   ============================================ */

const PostMeal = (() => {
  'use strict';

  const { api, $, $$, el, toast } = GrubFlip;

  let uploadedImage = null; // { url, thumb_url, upload_id }
  let submitting = false;

  const DIETARY_TAGS = [
    'vegan', 'vegetarian', 'gluten-free', 'dairy', 'dairy-free',
    'nut-free', 'halal', 'kosher', 'high-protein', 'low-carb', 'spicy'
  ];

  const CUISINES = [
    'Italian', 'Mexican', 'Chinese', 'Japanese', 'Indian', 'Thai',
    'Mediterranean', 'American', 'Korean', 'Vietnamese', 'French',
    'Middle Eastern', 'Caribbean', 'Ethiopian', 'Other'
  ];

  // --- Image Upload ---
  function setupImageUpload() {
    const zone = $('#upload-zone');
    const fileInput = $('#image-input');
    if (!zone || !fileInput) return;

    // Click to select
    zone.addEventListener('click', (e) => {
      if (e.target.closest('.btn--remove')) return;
      fileInput.click();
    });

    // File selected
    fileInput.addEventListener('change', () => {
      if (fileInput.files.length) handleFile(fileInput.files[0]);
    });

    // Drag and drop
    zone.addEventListener('dragover', (e) => {
      e.preventDefault();
      zone.classList.add('dragover');
    });

    zone.addEventListener('dragleave', () => {
      zone.classList.remove('dragover');
    });

    zone.addEventListener('drop', (e) => {
      e.preventDefault();
      zone.classList.remove('dragover');
      const file = e.dataTransfer.files[0];
      if (file) handleFile(file);
    });

    // Remove button
    const removeBtn = zone.querySelector('.btn--remove');
    if (removeBtn) {
      removeBtn.addEventListener('click', (e) => {
        e.stopPropagation();
        clearUpload();
      });
    }
  }

  async function handleFile(file) {
    // Validate
    const validTypes = ['image/jpeg', 'image/png', 'image/webp'];
    if (!validTypes.includes(file.type)) {
      toast('Please upload a JPG, PNG, or WebP image', 'error');
      return;
    }

    if (file.size > 20 * 1024 * 1024) {
      toast('Image must be under 20MB', 'error');
      return;
    }

    const zone = $('#upload-zone');
    const previewImg = $('#upload-preview-img');

    // Show local preview immediately
    const reader = new FileReader();
    reader.onload = (e) => {
      previewImg.src = e.target.result;
      zone.classList.add('has-preview');
    };
    reader.readAsDataURL(file);

    // Upload to server
    try {
      zone.style.opacity = '0.7';
      const data = await api.upload('/uploads/image', file);
      uploadedImage = {
        url: data.url,
        thumb_url: data.thumb_url,
        upload_id: data.upload_id,
      };
      toast('Image uploaded!', 'success');
    } catch (err) {
      toast('Upload failed — ' + err.message, 'error');
      clearUpload();
    } finally {
      zone.style.opacity = '';
    }
  }

  function clearUpload() {
    uploadedImage = null;
    const zone = $('#upload-zone');
    const fileInput = $('#image-input');
    const previewImg = $('#upload-preview-img');

    if (zone) zone.classList.remove('has-preview');
    if (fileInput) fileInput.value = '';
    if (previewImg) previewImg.src = '';
  }

  // --- Expiry Picker ---
  function setupExpiryPicker() {
    const select = $('#expires-select');
    if (!select) return;

    // Populate with reasonable time windows
    const options = [
      { value: '2', label: '2 hours' },
      { value: '4', label: '4 hours' },
      { value: '6', label: '6 hours' },
      { value: '8', label: '8 hours' },
      { value: '12', label: '12 hours' },
      { value: '24', label: '24 hours' },
    ];

    select.innerHTML = '<option value="">Pick up within...</option>';
    for (const opt of options) {
      select.appendChild(el('option', { value: opt.value, textContent: opt.label }));
    }
  }

  // --- Form Validation ---
  function validate() {
    const errors = [];
    const title = $('#meal-title')?.value.trim();
    const description = $('#meal-description')?.value.trim();
    const expiresHours = $('#expires-select')?.value;

    if (!title || title.length < 3) errors.push({ field: 'meal-title', msg: 'Title must be at least 3 characters' });
    if (title && title.length > 100) errors.push({ field: 'meal-title', msg: 'Title is too long (max 100 chars)' });
    if (!description) errors.push({ field: 'meal-description', msg: 'Add a short description' });
    if (!expiresHours) errors.push({ field: 'expires-select', msg: 'Set a pickup window' });
    if (!uploadedImage) errors.push({ field: 'upload-zone', msg: 'Add a photo of your meal' });

    // Clear previous errors
    $$('.form-error').forEach(el => el.remove());
    $$('.form-input, .form-textarea, .form-select').forEach(el => el.style.borderColor = '');

    // Show errors
    for (const error of errors) {
      const fieldEl = $(`#${error.field}`);
      if (fieldEl) {
        fieldEl.style.borderColor = 'var(--gf-error)';
        const errEl = document.createElement('p');
        errEl.className = 'form-error';
        errEl.textContent = error.msg;
        fieldEl.parentElement.appendChild(errEl);
      }
    }

    return errors.length === 0;
  }

  // --- Submit ---
  async function handleSubmit(e) {
    e.preventDefault();
    if (submitting) return;
    if (!validate()) return;

    submitting = true;
    const submitBtn = $('#submit-btn');
    if (submitBtn) {
      submitBtn.disabled = true;
      submitBtn.textContent = 'Posting...';
    }

    // Gather selected dietary tags
    const selectedTags = $$('.tag-picker__option:checked').map(cb => cb.value);

    const expiresHours = parseInt($('#expires-select').value, 10);
    const expiresAt = new Date(Date.now() + expiresHours * 3600000).toISOString();

    const payload = {
      title: $('#meal-title').value.trim(),
      description: $('#meal-description').value.trim(),
      upload_id: uploadedImage.upload_id,
      dietary_tags: selectedTags,
      cuisine: $('#cuisine-select').value || null,
      portion_size: $('#portion-select').value || 'single',
      trade_type: $('#trade-type-select')?.value || 'swap',
      expires_at: expiresAt,
    };

    try {
      const result = await api.post('/meals', payload);
      toast('Meal posted! 🎉', 'success');
      // Redirect to feed after short delay
      setTimeout(() => {
        window.location.href = '/grubflip/index.html';
      }, 1000);
    } catch (err) {
      toast('Failed to post — ' + err.message, 'error');
    } finally {
      submitting = false;
      if (submitBtn) {
        submitBtn.disabled = false;
        submitBtn.textContent = 'Post Meal';
      }
    }
  }

  // --- Init ---
  function init() {
    const form = $('#post-meal-form');
    if (!form) return;

    setupImageUpload();
    setupExpiryPicker();

    form.addEventListener('submit', handleSubmit);

    // Character counter for description
    const desc = $('#meal-description');
    const counter = $('#desc-counter');
    if (desc && counter) {
      desc.addEventListener('input', () => {
        const len = desc.value.length;
        counter.textContent = `${len}/300`;
        counter.style.color = len > 300 ? 'var(--gf-error)' : 'var(--gf-neutral-400)';
      });
    }
  }

  return { init };
})();

document.addEventListener('DOMContentLoaded', PostMeal.init);