// Tab Switch Logic
  document.addEventListener('DOMContentLoaded', function() {
    const tabButtons = document.querySelectorAll('.tab-btn');
    const tabPanels = document.querySelectorAll('.tab-panel');

    tabButtons.forEach(button => {
      button.addEventListener('click', () => {
        // Deactivate active tab
        tabButtons.forEach(btn => {
          btn.classList.remove('active', 'bg-blue-50', 'border-blue-100', 'text-blue-900');
          btn.classList.add('bg-transparent', 'border-transparent', 'text-slate-600');
          btn.querySelector('.tab-icon').classList.remove('bg-blue-600', 'text-white');
          btn.querySelector('.tab-icon').classList.add('bg-slate-50', 'text-slate-500');
          btn.setAttribute('aria-selected', 'false');
        });

        // Hide active panels
        tabPanels.forEach(panel => {
          panel.classList.add('hidden');
        });

        // Activate clicked tab
        button.classList.add('active', 'bg-blue-50', 'border-blue-100', 'text-blue-900');
        button.classList.remove('bg-transparent', 'border-transparent', 'text-slate-600');
        button.querySelector('.tab-icon').classList.add('bg-blue-600', 'text-white');
        button.querySelector('.tab-icon').classList.remove('bg-slate-50', 'text-slate-500');
        button.setAttribute('aria-selected', 'true');

        // Show targets panel
        const targetId = button.getAttribute('data-tab-target');
        const targetPanel = document.getElementById(targetId + '-panel');
        if (targetPanel) {
          targetPanel.classList.remove('hidden');
        }
      });
    });

  let quill;

  // Tab Switch Logic
  document.addEventListener('DOMContentLoaded', function() {
    // Initialize Quill editor
    quill = new Quill('#editor-content-quill', {
      theme: 'snow',
      modules: {
        toolbar: [
          ['bold', 'italic', 'underline', 'strike'],        // toggled buttons
          [{ 'list': 'ordered'}, { 'list': 'bullet' }],
          ['clean']                                         // remove formatting button
        ]
      }
    });

    const tabButtons = document.querySelectorAll('.tab-btn');
    const tabPanels = document.querySelectorAll('.tab-panel');

    tabButtons.forEach(button => {
      button.addEventListener('click', () => {
        // Deactivate active tab
        tabButtons.forEach(btn => {
          btn.classList.remove('active', 'bg-blue-50', 'border-blue-100', 'text-blue-900');
          btn.classList.add('bg-transparent', 'border-transparent', 'text-slate-600');
          btn.querySelector('.tab-icon').classList.remove('bg-blue-600', 'text-white');
          btn.querySelector('.tab-icon').classList.add('bg-slate-50', 'text-slate-500');
          btn.setAttribute('aria-selected', 'false');
        });

        // Hide active panels
        tabPanels.forEach(panel => {
          panel.classList.add('hidden');
        });

        // Activate clicked tab
        button.classList.add('active', 'bg-blue-50', 'border-blue-100', 'text-blue-900');
        button.classList.remove('bg-transparent', 'border-transparent', 'text-slate-600');
        button.querySelector('.tab-icon').classList.add('bg-blue-600', 'text-white');
        button.querySelector('.tab-icon').classList.remove('bg-slate-50', 'text-slate-500');
        button.setAttribute('aria-selected', 'true');

        // Show targets panel
        const targetId = button.getAttribute('data-tab-target');
        const targetPanel = document.getElementById(targetId + '-panel');
        if (targetPanel) {
          targetPanel.classList.remove('hidden');
        }
      });
    });

    // Handle initial state of date logic
    calculateEndDateFrontend();
    
    // Fetch Github commits in memory if repo is set
    fetchAllCommitsInMemory();
    
    // Select first day of the notebook workspace on load
    selectNotebookDay(0);
  });

  const githubRepoUrl = "dummy";
  let allGithubCommits = {};
  let activeDayIdx = 0;

  function fetchAllCommitsInMemory() {
    if (!githubRepoUrl) return;

    let repoClean = githubRepoUrl.replace(/https?:\/\/(www\.)?github\.com\//i, '');
    repoClean = repoClean.replace(/\/$/, '');
    const parts = repoClean.split('/');
    if (parts.length < 2) return;

    const owner = parts[0];
    const repo = parts[1].replace(/\.git$/i, '');

    fetch(`https://api.github.com/repos/${owner}/${repo}/commits?per_page=100`)
      .then(response => {
        if (!response.ok) throw new Error('API Error');
        return response.json();
      })
      .then(commits => {
        if (!Array.isArray(commits)) return;
        commits.forEach(item => {
          const dateStr = item.commit.author.date;
          if (dateStr) {
            const dateOnly = dateStr.substring(0, 10);
            if (!allGithubCommits[dateOnly]) {
              allGithubCommits[dateOnly] = [];
            }
            allGithubCommits[dateOnly].push(item);
          }
        });
      })
      .catch(err => {
        console.warn('Commits could not be pre-loaded in memory.', err);
      });
  }

  function selectNotebookDay(idx) {
    const oldBtn = document.getElementById(`btn-day-${activeDayIdx}`);
    if (oldBtn) {
      oldBtn.classList.remove('border-blue-200', 'bg-blue-50/50');
      oldBtn.classList.add('border-slate-100', 'bg-white');
      const oldTitle = oldBtn.querySelector('span.text-xs');
      if (oldTitle) {
          oldTitle.classList.remove('text-blue-700');
          oldTitle.classList.add('text-slate-800');
      }
    }

    activeDayIdx = idx;
    const newBtn = document.getElementById(`btn-day-${idx}`);
    if (newBtn) {
      newBtn.classList.add('border-blue-200', 'bg-blue-50/50');
      newBtn.classList.remove('border-slate-100', 'bg-white');
      const newTitle = newBtn.querySelector('span.text-xs');
      if (newTitle) {
          newTitle.classList.add('text-blue-700');
          newTitle.classList.remove('text-slate-800');
      }

      const dayNum = newBtn.getAttribute('data-day-num');
      const dateVal = newBtn.getAttribute('data-date');
      const dateFormatted = newBtn.getAttribute('data-formatted-date');
      const savedContent = newBtn.getAttribute('data-saved-content');

      document.getElementById('editor-day-title').textContent = `${dayNum}. Gün`;
      document.getElementById('editor-day-date').textContent = dateFormatted;
      
      quill.root.innerHTML = savedContent || '';
      document.getElementById('save-status').textContent = '';

      // Future validation
      const dateParts = dateVal.split('-');
      const selectedDate = new Date(dateParts[0], dateParts[1] - 1, dateParts[2]);
      const today = new Date();
      today.setHours(0,0,0,0);
      
      const isFuture = selectedDate > today;
      const warningBlock = document.getElementById('future-warning');
      const saveBtn = document.getElementById('save-btn');
      const gitBtn = document.querySelector('button[onclick="fillFromGithub()"]');

      if (isFuture) {
          warningBlock.classList.remove('hidden');
          quill.enable(false);
          saveBtn.disabled = true;
          saveBtn.classList.add('opacity-50', 'cursor-not-allowed');
          if (gitBtn) {
              gitBtn.disabled = true;
              gitBtn.classList.add('opacity-50', 'cursor-not-allowed');
          }
      } else {
          warningBlock.classList.add('hidden');
          quill.enable(true);
          saveBtn.disabled = false;
          saveBtn.classList.remove('opacity-50', 'cursor-not-allowed');
          if (gitBtn) {
              gitBtn.disabled = false;
              gitBtn.classList.remove('opacity-50', 'cursor-not-allowed');
          }
      }
    }
  }

  function fillFromGithub() {
    const btn = document.getElementById(`btn-day-${activeDayIdx}`);
    if (!btn) return;

    const dateVal = btn.getAttribute('data-date');
    const dayCommits = allGithubCommits[dateVal] || [];

    if (dayCommits.length === 0) {
      alert("Bu staj gününe ait GitHub commit'i bulunamadı. Lütfen commit attığınızdan ve tarihin doğru olduğundan emin olun.");
      return;
    }

    let commitHtml = "<ul>";
    const sorted = [...dayCommits].reverse();
    sorted.forEach(c => {
      const msg = c.commit.message;
      const sha = c.sha.substring(0, 7);
      const authorDate = new Date(c.commit.author.date);
      const time = authorDate.toLocaleTimeString('tr-TR', { hour: '2-digit', minute: '2-digit' });
      commitHtml += `<li><strong>[${time}]</strong> (<em>${sha}</em>) ${msg}</li>`;
    });
    commitHtml += "</ul>";

    const currentHtml = quill.root.innerHTML.trim();
    if (currentHtml !== "" && currentHtml !== "<p><br></p>") {
      if (confirm("Mevcut rapor içeriğinizin sonuna bu günün commitlerini eklemek ister misiniz? (Hayır derseniz mevcut içerik silinip commitler yazılır.)")) {
        quill.root.innerHTML = currentHtml + "<br><br>" + commitHtml;
      } else {
        quill.root.innerHTML = commitHtml;
      }
    } else {
      quill.root.innerHTML = commitHtml;
    }
  }

  function saveActiveDay() {
    const btn = document.getElementById(`btn-day-${activeDayIdx}`);
    if (!btn) return;

    const dayNum = btn.getAttribute('data-day-num');
    const dateVal = btn.getAttribute('data-date');
    let contentVal = quill.root.innerHTML;
    if (contentVal === '<p><br></p>') {
        contentVal = '';
    }
    const statusText = document.getElementById('save-status');

    statusText.textContent = "Kaydediliyor...";
    statusText.className = "text-xs font-semibold text-slate-400 animate-pulse";

    fetch(""dummy"", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        "X-CSRF-TOKEN": ""dummy""
      },
      body: JSON.stringify({
        day_number: dayNum,
        date: dateVal,
        content: contentVal
      })
    })
    .then(response => response.json())
    .then(data => {
      if (data.success) {
        statusText.textContent = "Başarıyla kaydedildi.";
        statusText.className = "text-xs font-semibold text-green-600";

        btn.setAttribute('data-saved-content', contentVal);

        const badge = document.getElementById(`badge-day-${activeDayIdx}`);
        if (badge) {
          if (contentVal.trim() !== '') {
            badge.textContent = 'DOLU';
            badge.className = "inline-flex px-2 py-0.5 rounded-lg text-[9px] font-extrabold uppercase bg-green-50 text-green-700 border border-green-200";
          } else {
            badge.textContent = 'BOŞ';
            badge.className = "inline-flex px-2 py-0.5 rounded-lg text-[9px] font-extrabold uppercase bg-slate-50 text-slate-400 border border-slate-200";
          }
        }
      } else {
        statusText.textContent = data.message || "Kaydedilemedi.";
        statusText.className = "text-xs font-semibold text-red-600";
      }
    })
    .catch(err => {
      console.error(err);
      statusText.textContent = "Bağlantı hatası oluştu.";
      statusText.className = "text-xs font-semibold text-red-600";
    });
  }

  function openPrintModal() {
    const modal = document.getElementById('print-modal');
    const card = document.getElementById('print-modal-card');
    modal.classList.remove('hidden');
    setTimeout(() => {
      card.classList.remove('scale-95', 'opacity-0');
      card.classList.add('scale-100', 'opacity-100');
    }, 10);
  }

  function closePrintModal() {
    const modal = document.getElementById('print-modal');
    const card = document.getElementById('print-modal-card');
    card.classList.remove('scale-100', 'opacity-100');
    card.classList.add('scale-95', 'opacity-0');
    setTimeout(() => {
      modal.classList.add('hidden');
    }, 300);
  }

  function handleFileSelected(input) {
    const fileNameElement = document.getElementById('selected-file-name');
    const submitBtn = document.getElementById('submit-upload-btn');
    if (input.files && input.files.length > 0) {
      const file = input.files[0];
      const fileSizeMB = file.size / (1024 * 1024);
      if (fileSizeMB > 50) {
        alert('Dosya boyutu 50MB\'ı aşamaz.');
        input.value = '';
        fileNameElement.textContent = '';
        submitBtn.disabled = true;
        submitBtn.classList.add('opacity-50', 'cursor-not-allowed');
        return;
      }
      fileNameElement.textContent = 'Seçilen dosya: ' + file.name + ' (' + fileSizeMB.toFixed(2) + ' MB)';
      submitBtn.disabled = false;
      submitBtn.classList.remove('opacity-50', 'cursor-not-allowed');
    } else {
      fileNameElement.textContent = '';
      submitBtn.disabled = true;
      submitBtn.classList.add('opacity-50', 'cursor-not-allowed');
    }
  }

  function calculateEndDateFrontend() {
    const startDateVal = document.getElementById('internship_start_date').value;
    const totalDaysVal = document.getElementById('internship_total_days').value;
    const endDateInput = document.getElementById('internship_end_date');
    
    if (!startDateVal || !totalDaysVal || totalDaysVal <= 0) {
      return;
    }
    
    let date = new Date(startDateVal);
    let daysToAdd = parseInt(totalDaysVal);
    let count = 0;
    let endDate = new Date(startDateVal);
    
    while (count < daysToAdd) {
      const dayOfWeek = date.getDay();
      if (dayOfWeek === 6 || dayOfWeek === 0) { // 6 = Saturday, 0 = Sunday
        date.setDate(date.getDate() + 1);
        continue;
      }
      endDate = new Date(date);
      date.setDate(date.getDate() + 1);
      count++;
    }
    
    // Format to YYYY-MM-DD
    const yyyy = endDate.getFullYear();
    const mm = String(endDate.getMonth() + 1).padStart(2, '0');
    const dd = String(endDate.getDate()).padStart(2, '0');
    endDateInput.value = `${yyyy}-${mm}-${dd}`;
  }

  function copyToClipboard(elementId, btn) {
    const text = document.getElementById(elementId).textContent;
    navigator.clipboard.writeText(text).then(() => {
      const icon = btn.querySelector('i');
      const originalClass = icon.className;
      icon.className = 'uil uil-check text-green-500';
      setTimeout(() => {
        icon.className = originalClass;
      }, 2000);
    });
  }