const state = {
  documents: [],
  reviewers: [],
  notifications: [],
  selectedId: null,
  selectedDocument: null,
  filter: "all",
  view: "documents",
  reviewerAction: "comment",
};

const els = {
  fileInput: document.querySelector("#fileInput"),
  uploadButton: document.querySelector("#uploadButton"),
  dropZone: document.querySelector("#dropZone"),
  ownerName: document.querySelector("#ownerName"),
  ownerEmail: document.querySelector("#ownerEmail"),
  ownerSlack: document.querySelector("#ownerSlack"),
  ownerTeams: document.querySelector("#ownerTeams"),
  sideTabs: document.querySelectorAll(".side-tab"),
  documentsView: document.querySelector("#documentsView"),
  reviewersView: document.querySelector("#reviewersView"),
  notificationsView: document.querySelector("#notificationsView"),
  notificationBadge: document.querySelector("#notificationBadge"),
  filters: document.querySelectorAll(".filter"),
  documentList: document.querySelector("#documentList"),
  reviewerForm: document.querySelector("#reviewerForm"),
  reviewerId: document.querySelector("#reviewerId"),
  reviewerName: document.querySelector("#reviewerName"),
  reviewerEmail: document.querySelector("#reviewerEmail"),
  reviewerSlack: document.querySelector("#reviewerSlack"),
  reviewerTeams: document.querySelector("#reviewerTeams"),
  reviewerSaveButton: document.querySelector("#reviewerSaveButton"),
  reviewerCancelButton: document.querySelector("#reviewerCancelButton"),
  reviewerList: document.querySelector("#reviewerList"),
  notificationList: document.querySelector("#notificationList"),
  emptyState: document.querySelector("#emptyState"),
  documentPanel: document.querySelector("#documentPanel"),
  documentMeta: document.querySelector("#documentMeta"),
  documentTitle: document.querySelector("#documentTitle"),
  ownerLine: document.querySelector("#ownerLine"),
  statusPill: document.querySelector("#statusPill"),
  downloadButton: document.querySelector("#downloadButton"),
  reviewButton: document.querySelector("#reviewButton"),
  assignmentSummary: document.querySelector("#assignmentSummary"),
  assignmentForm: document.querySelector("#assignmentForm"),
  assignmentChoices: document.querySelector("#assignmentChoices"),
  assignmentList: document.querySelector("#assignmentList"),
  reviewerActionForm: document.querySelector("#reviewerActionForm"),
  reviewerActionSelect: document.querySelector("#reviewerActionSelect"),
  reviewerSignature: document.querySelector("#reviewerSignature"),
  reviewerNote: document.querySelector("#reviewerNote"),
  findings: document.querySelector("#findings"),
  findingSummary: document.querySelector("#findingSummary"),
  commentForm: document.querySelector("#commentForm"),
  commentBody: document.querySelector("#commentBody"),
  comments: document.querySelector("#comments"),
  commentCount: document.querySelector("#commentCount"),
  activityTimeline: document.querySelector("#activityTimeline"),
  activityCount: document.querySelector("#activityCount"),
  textPreview: document.querySelector("#textPreview"),
  wordCount: document.querySelector("#wordCount"),
  toast: document.querySelector("#toast"),
};

async function api(path, options = {}) {
  return new Promise((resolve, reject) => {
    const request = new XMLHttpRequest();
    request.open(options.method || "GET", path, true);
    for (const [key, value] of Object.entries(options.headers || {})) {
      request.setRequestHeader(key, value);
    }
    request.onload = () => {
      const contentType = request.getResponseHeader("Content-Type") || "";
      const payload = contentType.includes("application/json") && request.responseText
        ? JSON.parse(request.responseText)
        : null;
      if (request.status >= 200 && request.status < 300) {
        resolve(payload);
      } else {
        reject(new Error(payload?.error || `Request failed with ${request.status}`));
      }
    };
    request.onerror = () => reject(new Error("Request failed."));
    request.send(options.body || null);
  });
}

function showToast(message, isError = false) {
  els.toast.textContent = message;
  els.toast.classList.toggle("error", isError);
  els.toast.classList.remove("hidden");
  clearTimeout(showToast.timer);
  showToast.timer = setTimeout(() => els.toast.classList.add("hidden"), 3600);
}

function formatDate(value) {
  if (!value) return "Not recorded";
  return new Intl.DateTimeFormat(undefined, {
    month: "short",
    day: "numeric",
    hour: "numeric",
    minute: "2-digit",
  }).format(new Date(value));
}

function countsFor(document) {
  const counts = { high: 0, medium: 0, low: 0 };
  for (const finding of document.findings || []) {
    counts[finding.severity] += 1;
  }
  return counts;
}

function contactLine(contact = {}) {
  return [contact.email, contact.slack, contact.teams].filter(Boolean).join(" | ");
}

async function loadAll() {
  const [documents, reviewers, notifications] = await Promise.all([
    api("/api/documents"),
    api("/api/reviewers"),
    api("/api/notifications"),
  ]);
  state.documents = documents.documents;
  state.reviewers = reviewers.reviewers;
  state.notifications = notifications.notifications;
  renderNavigation(notifications.unread_count || 0);
  renderList();
  renderReviewerList();
  renderNotifications();

  if (state.selectedId && state.documents.some((doc) => doc.id === state.selectedId)) {
    await selectDocument(state.selectedId);
  } else if (state.documents.length > 0 && !state.selectedId) {
    await selectDocument(state.documents[0].id);
  } else if (state.documents.length === 0) {
    renderEmpty();
  }
}

async function refreshSelected() {
  const [documents, notifications] = await Promise.all([api("/api/documents"), api("/api/notifications")]);
  state.documents = documents.documents;
  state.notifications = notifications.notifications;
  renderNavigation(notifications.unread_count || 0);
  renderList();
  renderNotifications();
  if (state.selectedId) {
    state.selectedDocument = await api(`/api/documents/${state.selectedId}`);
    renderDocument();
  }
}

function renderNavigation(unreadCount = 0) {
  els.sideTabs.forEach((button) => button.classList.toggle("active", button.dataset.view === state.view));
  els.documentsView.classList.toggle("hidden", state.view !== "documents");
  els.reviewersView.classList.toggle("hidden", state.view !== "reviewers");
  els.notificationsView.classList.toggle("hidden", state.view !== "notifications");
  els.notificationBadge.textContent = `${unreadCount}`;
  els.notificationBadge.classList.toggle("hidden", unreadCount === 0);
}

function renderList() {
  const filtered = state.documents.filter((document) => {
    if (state.filter === "all") return true;
    if (state.filter === "in_review") return document.status === "in_review" || document.status === "uploaded";
    return document.status === state.filter;
  });

  if (!filtered.length) {
    els.documentList.innerHTML = `<p class="quiet">No documents in this view.</p>`;
    return;
  }

  els.documentList.innerHTML = filtered
    .map((document) => {
      const counts = countsFor(document);
      const assignments = document.assignment_counts || {};
      return `
        <button class="queue-item ${document.id === state.selectedId ? "active" : ""}" type="button" data-id="${document.id}">
          <span class="queue-title">${escapeHtml(document.filename)}</span>
          <span class="queue-meta">
            <span>${escapeHtml(document.status_label)}</span>
            <span>${document.word_count || 0} words</span>
          </span>
          <span class="queue-meta">
            <span>${assignments.approved || 0}/${assignmentTotal(assignments)} approved</span>
            <span class="mini-counts" title="High, medium, and low findings">
              <span>${counts.high}</span><span>${counts.medium}</span><span>${counts.low}</span>
            </span>
          </span>
        </button>
      `;
    })
    .join("");

  els.documentList.querySelectorAll("[data-id]").forEach((button) => {
    button.addEventListener("click", () => selectDocument(button.dataset.id));
  });
}

function assignmentTotal(counts) {
  return (counts.pending || 0) + (counts.commented || 0) + (counts.changes_requested || 0) + (counts.approved || 0);
}

function renderEmpty() {
  state.selectedDocument = null;
  els.emptyState.classList.remove("hidden");
  els.documentPanel.classList.add("hidden");
}

async function selectDocument(id) {
  state.selectedId = id;
  state.selectedDocument = await api(`/api/documents/${id}`);
  renderList();
  renderDocument();
}

function renderDocument() {
  const document = state.selectedDocument;
  if (!document) {
    renderEmpty();
    return;
  }

  els.emptyState.classList.add("hidden");
  els.documentPanel.classList.remove("hidden");
  els.documentTitle.textContent = document.filename;
  els.documentMeta.textContent = `${document.extension.toUpperCase().replace(".", "")} | Uploaded ${formatDate(document.created_at)}`;
  els.ownerLine.textContent = `Owner: ${document.owner?.name || "Owner"}${contactLine(document.owner) ? ` | ${contactLine(document.owner)}` : ""}`;
  els.statusPill.textContent = document.status_label;
  els.statusPill.className = `status-pill ${document.status}`;
  els.wordCount.textContent = `${document.word_count || 0} words`;
  els.textPreview.textContent = document.text || "";
  els.downloadButton.onclick = () => {
    window.location.href = `/api/documents/${document.id}/download`;
  };

  renderAssignments(document);
  renderFindings(document);
  renderComments(document);
  renderActivity(document);
}

function renderAssignments(document) {
  const selectedReviewerIds = new Set((document.assignments || []).map((assignment) => assignment.reviewer_id));
  if (!state.reviewers.length) {
    els.assignmentChoices.innerHTML = `<p class="quiet">Add reviewers in the sidebar first.</p>`;
  } else {
    els.assignmentChoices.innerHTML = state.reviewers
      .map(
        (reviewer) => `
          <label class="check-card">
            <input type="checkbox" value="${escapeHtml(reviewer.id)}" ${selectedReviewerIds.has(reviewer.id) ? "checked" : ""}>
            <span>
              <strong>${escapeHtml(reviewer.name)}</strong>
              <small>${escapeHtml(contactLine(reviewer) || "No contact set")}</small>
            </span>
          </label>
        `,
      )
      .join("");
  }

  const counts = document.assignment_counts || {};
  const total = assignmentTotal(counts);
  els.assignmentSummary.textContent = total ? `${counts.approved || 0}/${total} approved` : "No reviewers";

  if (!(document.assignments || []).length) {
    els.assignmentList.innerHTML = `<p class="quiet">No reviewers assigned.</p>`;
    els.reviewerActionSelect.innerHTML = `<option value="">Assign a reviewer first</option>`;
    els.reviewerActionForm.classList.add("muted-panel");
    return;
  }

  els.reviewerActionForm.classList.remove("muted-panel");
  els.assignmentList.innerHTML = document.assignments
    .map(
      (assignment) => `
        <article class="assignment-card ${assignment.status}">
          <div>
            <strong>${escapeHtml(assignment.reviewer_name)}</strong>
            <small>${escapeHtml(contactLine(assignment.reviewer_contact) || "No contact set")}</small>
          </div>
          <span class="status-chip ${assignment.status}">${escapeHtml(assignment.status_label)}</span>
          ${assignment.approved_at ? `<small>Approved ${formatDate(assignment.approved_at)} as ${escapeHtml(assignment.approval_name)}</small>` : ""}
        </article>
      `,
    )
    .join("");
  els.reviewerActionSelect.innerHTML = document.assignments
    .map((assignment) => `<option value="${escapeHtml(assignment.reviewer_id)}">${escapeHtml(assignment.reviewer_name)}</option>`)
    .join("");
}

function renderFindings(document) {
  const findings = document.findings || [];
  if (!document.reviewed_at) {
    els.findingSummary.textContent = "Not reviewed";
    els.findings.innerHTML = `<p class="quiet">Run a review to check required sections, placeholders, and vague language.</p>`;
    return;
  }

  const counts = countsFor(document);
  els.findingSummary.textContent = `${counts.high} high, ${counts.medium} medium, ${counts.low} low`;

  if (!findings.length) {
    els.findings.innerHTML = `<p class="quiet">No findings from the local rubric.</p>`;
    return;
  }

  const groups = ["high", "medium", "low"]
    .map((severity) => findings.filter((finding) => finding.severity === severity))
    .filter((group) => group.length);

  els.findings.innerHTML = groups
    .map((group) => {
      const severity = group[0].severity;
      return `
        <div class="finding-group">
          <div class="severity-heading">
            <span class="severity-dot ${severity}"></span>
            ${severity} severity
          </div>
          ${group.map(renderFinding).join("")}
        </div>
      `;
    })
    .join("");
}

function renderFinding(finding) {
  return `
    <article class="finding ${finding.severity}">
      <h4>${escapeHtml(finding.title)}</h4>
      <p>${escapeHtml(finding.detail)}</p>
      ${finding.snippet ? `<div class="snippet">${escapeHtml(finding.snippet)}</div>` : ""}
    </article>
  `;
}

function renderComments(document) {
  const comments = document.comments || [];
  els.commentCount.textContent = `${comments.length}`;
  if (!comments.length) {
    els.comments.innerHTML = `<p class="quiet">No comments yet.</p>`;
    return;
  }
  els.comments.innerHTML = comments
    .slice()
    .reverse()
    .map(
      (comment) => `
        <article class="comment">
          <strong>${escapeHtml(comment.author)}</strong>
          <time>${formatDate(comment.created_at)}</time>
          <p>${escapeHtml(comment.body)}</p>
        </article>
      `,
    )
    .join("");
}

function renderActivity(document) {
  const activity = document.activity || [];
  els.activityCount.textContent = `${activity.length}`;
  if (!activity.length) {
    els.activityTimeline.innerHTML = `<p class="quiet">No activity yet.</p>`;
    return;
  }
  els.activityTimeline.innerHTML = activity
    .map(
      (item) => `
        <article class="timeline-item">
          <span></span>
          <div>
            <strong>${escapeHtml(item.actor)}</strong>
            <p>${escapeHtml(item.message)}</p>
            <time>${formatDate(item.created_at)}</time>
          </div>
        </article>
      `,
    )
    .join("");
}

function renderReviewerList() {
  if (!state.reviewers.length) {
    els.reviewerList.innerHTML = `<p class="quiet">No reviewers yet.</p>`;
    return;
  }
  els.reviewerList.innerHTML = state.reviewers
    .map(
      (reviewer) => `
        <article class="person-card">
          <div>
            <strong>${escapeHtml(reviewer.name)}</strong>
            <small>${escapeHtml(contactLine(reviewer) || "No contact set")}</small>
          </div>
          <div class="icon-row">
            <button class="secondary tiny" type="button" data-edit-reviewer="${escapeHtml(reviewer.id)}">Edit</button>
            <button class="secondary tiny danger-text" type="button" data-delete-reviewer="${escapeHtml(reviewer.id)}">Remove</button>
          </div>
        </article>
      `,
    )
    .join("");

  els.reviewerList.querySelectorAll("[data-edit-reviewer]").forEach((button) => {
    button.addEventListener("click", () => editReviewer(button.dataset.editReviewer));
  });
  els.reviewerList.querySelectorAll("[data-delete-reviewer]").forEach((button) => {
    button.addEventListener("click", () => deleteReviewer(button.dataset.deleteReviewer));
  });
}

function renderNotifications() {
  if (!state.notifications.length) {
    els.notificationList.innerHTML = `<p class="quiet">No notifications yet.</p>`;
    return;
  }
  els.notificationList.innerHTML = state.notifications
    .map(
      (notification) => `
        <article class="notification-card ${notification.read_at ? "" : "unread"}">
          <div>
            <strong>${escapeHtml(notification.recipient_name)}</strong>
            <small>${escapeHtml(notification.recipient_type)} | ${formatDate(notification.created_at)}</small>
          </div>
          <p>${escapeHtml(notification.message)}</p>
          <div class="icon-row">
            <button class="secondary tiny" type="button" data-copy-notification="${escapeHtml(notification.id)}">Copy</button>
            ${
              notification.read_at
                ? `<span class="quiet tiny-label">Read</span>`
                : `<button class="secondary tiny" type="button" data-read-notification="${escapeHtml(notification.id)}">Mark read</button>`
            }
          </div>
        </article>
      `,
    )
    .join("");

  els.notificationList.querySelectorAll("[data-copy-notification]").forEach((button) => {
    button.addEventListener("click", () => copyNotification(button.dataset.copyNotification));
  });
  els.notificationList.querySelectorAll("[data-read-notification]").forEach((button) => {
    button.addEventListener("click", () => markNotificationRead(button.dataset.readNotification));
  });
}

async function uploadFile(file) {
  if (!file) return;
  const form = new FormData();
  form.append("file", file);
  form.append("owner_name", els.ownerName.value.trim());
  form.append("owner_email", els.ownerEmail.value.trim());
  form.append("owner_slack", els.ownerSlack.value.trim());
  form.append("owner_teams", els.ownerTeams.value.trim());
  els.uploadButton.disabled = true;
  els.uploadButton.textContent = "Uploading...";
  try {
    const document = await api("/api/upload", { method: "POST", body: form });
    showToast("Document uploaded.");
    state.selectedId = document.id;
    await loadAll();
  } catch (error) {
    showToast(error.message, true);
  } finally {
    els.uploadButton.disabled = false;
    els.uploadButton.innerHTML = `<span class="button-icon">+</span>Upload document`;
    els.fileInput.value = "";
  }
}

async function refreshSelectedWith(action, message) {
  if (!state.selectedId) return;
  try {
    state.selectedDocument = await api(`/api/documents/${state.selectedId}/${action}`, { method: "POST" });
    showToast(message);
    await refreshSelected();
  } catch (error) {
    showToast(error.message, true);
  }
}

async function saveReviewer(event) {
  event.preventDefault();
  const payload = {
    name: els.reviewerName.value.trim(),
    email: els.reviewerEmail.value.trim(),
    slack: els.reviewerSlack.value.trim(),
    teams: els.reviewerTeams.value.trim(),
  };
  const id = els.reviewerId.value;
  try {
    if (id) {
      await api(`/api/reviewers/${id}`, {
        method: "PUT",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(payload),
      });
      showToast("Reviewer updated.");
    } else {
      await api("/api/reviewers", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(payload),
      });
      showToast("Reviewer added.");
    }
    resetReviewerForm();
    await loadAll();
  } catch (error) {
    showToast(error.message, true);
  }
}

function editReviewer(id) {
  const reviewer = state.reviewers.find((item) => item.id === id);
  if (!reviewer) return;
  els.reviewerId.value = reviewer.id;
  els.reviewerName.value = reviewer.name;
  els.reviewerEmail.value = reviewer.email || "";
  els.reviewerSlack.value = reviewer.slack || "";
  els.reviewerTeams.value = reviewer.teams || "";
  els.reviewerSaveButton.textContent = "Update reviewer";
  els.reviewerCancelButton.classList.remove("hidden");
}

function resetReviewerForm() {
  els.reviewerForm.reset();
  els.reviewerId.value = "";
  els.reviewerSaveButton.textContent = "Save reviewer";
  els.reviewerCancelButton.classList.add("hidden");
}

async function deleteReviewer(id) {
  const reviewer = state.reviewers.find((item) => item.id === id);
  if (!reviewer) return;
  if (!window.confirm(`Remove ${reviewer.name} from the reviewer directory? Historical assignments stay on documents.`)) {
    return;
  }
  try {
    await api(`/api/reviewers/${id}`, { method: "DELETE" });
    showToast("Reviewer removed.");
    await loadAll();
  } catch (error) {
    showToast(error.message, true);
  }
}

async function assignReviewers(event) {
  event.preventDefault();
  if (!state.selectedId) return;
  const reviewerIds = Array.from(els.assignmentChoices.querySelectorAll("input[type='checkbox']:checked")).map((input) => input.value);
  try {
    await api(`/api/documents/${state.selectedId}/assign-reviewers`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ reviewer_ids: reviewerIds }),
    });
    showToast("Reviewer assignments updated.");
    await refreshSelected();
  } catch (error) {
    showToast(error.message, true);
  }
}

async function submitReviewerAction(event) {
  event.preventDefault();
  const submitter = event.submitter;
  const action = submitter?.dataset.reviewerAction || state.reviewerAction;
  const reviewerId = els.reviewerActionSelect.value;
  const signature = els.reviewerSignature.value.trim();
  const body = els.reviewerNote.value.trim();
  if (!reviewerId) {
    showToast("Choose an assigned reviewer.", true);
    return;
  }
  if (action === "approve" && !signature) {
    showToast("Enter a name or initials to approve.", true);
    return;
  }
  if ((action === "comment" || action === "request") && !body) {
    showToast("Add a note first.", true);
    return;
  }
  if (action === "approve" && (state.selectedDocument?.findings || []).length) {
    if (!window.confirm("This document still has review findings. Approve anyway?")) {
      return;
    }
  }

  const endpoint = {
    comment: "reviewer-comment",
    request: "reviewer-request-changes",
    approve: "reviewer-approve",
  }[action];

  try {
    await api(`/api/documents/${state.selectedId}/${endpoint}`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ reviewer_id: reviewerId, signature, body }),
    });
    els.reviewerNote.value = "";
    els.reviewerSignature.value = "";
    showToast(action === "approve" ? "Reviewer approval recorded." : "Reviewer response recorded.");
    await refreshSelected();
  } catch (error) {
    showToast(error.message, true);
  }
}

async function copyNotification(id) {
  const notification = state.notifications.find((item) => item.id === id);
  if (!notification) return;
  try {
    await navigator.clipboard.writeText(notification.message);
    showToast("Notification copied.");
  } catch {
    showToast(notification.message);
  }
}

async function markNotificationRead(id) {
  try {
    await api(`/api/notifications/${id}/read`, { method: "POST" });
    showToast("Notification marked read.");
    const payload = await api("/api/notifications");
    state.notifications = payload.notifications;
    renderNavigation(payload.unread_count || 0);
    renderNotifications();
  } catch (error) {
    showToast(error.message, true);
  }
}

function escapeHtml(value) {
  return String(value ?? "")
    .replaceAll("&", "&amp;")
    .replaceAll("<", "&lt;")
    .replaceAll(">", "&gt;")
    .replaceAll('"', "&quot;")
    .replaceAll("'", "&#039;");
}

els.sideTabs.forEach((button) => {
  button.addEventListener("click", () => {
    state.view = button.dataset.view;
    renderNavigation(state.notifications.filter((item) => !item.read_at).length);
  });
});

els.uploadButton.addEventListener("click", () => els.fileInput.click());
els.fileInput.addEventListener("change", () => uploadFile(els.fileInput.files[0]));

["dragenter", "dragover"].forEach((eventName) => {
  els.dropZone.addEventListener(eventName, (event) => {
    event.preventDefault();
    els.dropZone.classList.add("dragging");
  });
});

["dragleave", "drop"].forEach((eventName) => {
  els.dropZone.addEventListener(eventName, (event) => {
    event.preventDefault();
    els.dropZone.classList.remove("dragging");
  });
});

els.dropZone.addEventListener("drop", (event) => uploadFile(event.dataTransfer.files[0]));

els.filters.forEach((button) => {
  button.addEventListener("click", () => {
    state.filter = button.dataset.filter;
    els.filters.forEach((item) => item.classList.toggle("active", item === button));
    renderList();
  });
});

els.reviewerForm.addEventListener("submit", saveReviewer);
els.reviewerCancelButton.addEventListener("click", resetReviewerForm);
els.assignmentForm.addEventListener("submit", assignReviewers);
els.reviewerActionForm.addEventListener("submit", submitReviewerAction);
els.reviewButton.addEventListener("click", () => refreshSelectedWith("review", "Review complete."));

els.commentForm.addEventListener("submit", async (event) => {
  event.preventDefault();
  if (!state.selectedId) return;
  const body = els.commentBody.value.trim();
  if (!body) return;

  try {
    state.selectedDocument = await api(`/api/documents/${state.selectedId}/comments`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ body, author: state.selectedDocument?.owner?.name || "Owner" }),
    });
    els.commentBody.value = "";
    showToast("Comment added.");
    await refreshSelected();
  } catch (error) {
    showToast(error.message, true);
  }
});

loadAll().catch((error) => showToast(error.message, true));