<script setup lang="ts">
import { onMounted, onUnmounted, ref, watch } from "vue";
import { useRouter } from "vue-router";
import AppHeader from "@/components/AppHeader.vue";
import ToastNotification from "@/components/ToastNotification.vue";
import { useTheme } from "@/composables/useTheme";
import { useShortcuts } from "@/composables/useShortcuts";
import { useAuthStore } from "@/stores/auth";
import { useSettingsStore } from "@/stores/settings";
import { apiGet, apiPut } from "@/api/client";

useTheme();

const router = useRouter();
const appVersion = ref("dev");
const authStore = useAuthStore();
const settingsStore = useSettingsStore();
const { showShortcuts, toggleShortcuts, closeShortcuts } = useShortcuts();

function startAppServices() {
  settingsStore.fetchSettings();
  // Sync browser timezone to the server on every login/page load.
  apiPut("/api/settings", { user_timezone: Intl.DateTimeFormat().resolvedOptions().timeZone }).catch(() => {});
}

function stopAppServices() {
  // no-op for now; kept as a hook for future per-session teardown
}

function isInputActive(): boolean {
  const el = document.activeElement;
  if (!el) return false;
  const tag = (el as HTMLElement).tagName;
  return tag === "INPUT" || tag === "TEXTAREA" || (el as HTMLElement).isContentEditable;
}

// Sequence shortcut support (e.g. g+n, g+t)
let pendingPrefix: string | null = null;
let prefixTimeout: ReturnType<typeof setTimeout> | null = null;

function clearPrefix() {
  pendingPrefix = null;
  if (prefixTimeout) clearTimeout(prefixTimeout);
  prefixTimeout = null;
}

function onGlobalKeydown(e: KeyboardEvent) {
  if (!authStore.isAuthenticated) return;

  // ? — toggle shortcuts overlay (only when not typing)
  if (e.key === "?" && !isInputActive() && !e.ctrlKey && !e.metaKey) {
    toggleShortcuts();
    return;
  }

  // Escape — progressive: close overlay → unfocus field → go home
  if (e.key === "Escape") {
    clearPrefix();
    if (showShortcuts.value) {
      closeShortcuts();
      return;
    }
    if (isInputActive()) {
      (document.activeElement as HTMLElement).blur();
      return;
    }
    router.push("/");
    return;
  }

  // All remaining shortcuts: ignore when typing or using modifier keys
  if (isInputActive() || e.ctrlKey || e.metaKey || e.altKey) return;

  // Complete a g+X sequence
  if (pendingPrefix === "g") {
    clearPrefix();
    switch (e.key) {
      case "h": router.push("/"); break;
      case "n": router.push("/notes"); break;
      case "t": router.push("/"); break;
      case "p": router.push("/projects"); break;
      case "r": router.push("/rules"); break;
      case "g": router.push("/graph"); break;
      case "x": router.push("/trash"); break;
    }
    return;
  }

  // Single-key shortcuts
  switch (e.key) {
    case "g":
      pendingPrefix = "g";
      prefixTimeout = setTimeout(clearPrefix, 1500);
      break;
    case "n":
      router.push("/notes/new");
      break;
    case "t":
      router.push("/tasks/new");
      break;
    case "e": {
      const name = router.currentRoute.value.name;
      if (name === "note-view") {
        router.push(router.currentRoute.value.path + "/edit");
      }
      break;
    }
    case "/":
      e.preventDefault();
      document.dispatchEvent(new CustomEvent("shortcut:focus-search"));
      break;
  }
}

onMounted(async () => {
  document.addEventListener("keydown", onGlobalKeydown);
  await authStore.checkAuth();
  if (authStore.isAuthenticated) {
    startAppServices();
  }
  try {
    const data = await apiGet<{ version: string }>("/api/version");
    appVersion.value = data.version;
  } catch {
    // silent — version display is non-critical
  }
});

watch(
  () => authStore.isAuthenticated,
  (authenticated) => {
    if (authenticated) {
      startAppServices();
    } else {
      stopAppServices();
    }
  }
);

onUnmounted(() => {
  document.removeEventListener("keydown", onGlobalKeydown);
  stopAppServices();
});
</script>

<template>
  <template v-if="authStore.isAuthenticated">
    <a href="#main-content" class="skip-link">Skip to main content</a>
    <div class="app-shell">
      <AppHeader />
      <div id="main-content" class="app-content">
        <router-view />
      </div>
      <footer class="app-footer">v{{ appVersion }}</footer>
    </div>

    <!-- Keyboard shortcuts overlay -->
    <Transition name="shortcuts-fade">
      <div v-if="showShortcuts" class="shortcuts-overlay" @click.self="closeShortcuts">
        <div class="shortcuts-panel">
          <div class="shortcuts-header">
            <h3>Keyboard Shortcuts</h3>
            <button class="shortcuts-close" aria-label="Close keyboard shortcuts" @click="closeShortcuts">&times;</button>
          </div>
          <div class="shortcuts-body">
            <div class="shortcuts-section">
              <div class="shortcuts-section-title">Navigation</div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">g</kbd>
                <span class="shortcut-key-sep">+</span>
                <kbd class="shortcut-key">h</kbd>
                <span class="shortcut-desc">Home</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">g</kbd>
                <span class="shortcut-key-sep">+</span>
                <kbd class="shortcut-key">n</kbd>
                <span class="shortcut-desc">Notes</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">g</kbd>
                <span class="shortcut-key-sep">+</span>
                <kbd class="shortcut-key">t</kbd>
                <span class="shortcut-desc">Knowledge (tasks)</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">g</kbd>
                <span class="shortcut-key-sep">+</span>
                <kbd class="shortcut-key">p</kbd>
                <span class="shortcut-desc">Projects</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">g</kbd>
                <span class="shortcut-key-sep">+</span>
                <kbd class="shortcut-key">x</kbd>
                <span class="shortcut-desc">Trash</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">Esc</kbd>
                <span class="shortcut-desc">Unfocus field → go home</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">?</kbd>
                <span class="shortcut-desc">Toggle this panel</span>
              </div>
            </div>
            <div class="shortcuts-section">
              <div class="shortcuts-section-title">Create</div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">n</kbd>
                <span class="shortcut-desc">New note</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">t</kbd>
                <span class="shortcut-desc">New task</span>
              </div>
            </div>
            <div class="shortcuts-section">
              <div class="shortcuts-section-title">Lists</div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">/</kbd>
                <span class="shortcut-desc">Focus search bar</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">j</kbd>
                <span class="shortcut-key-sep">/</span>
                <kbd class="shortcut-key">k</kbd>
                <span class="shortcut-desc">Move down / up</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">Enter</kbd>
                <span class="shortcut-desc">Open selected item</span>
              </div>
              <div class="shortcut-row">
                <kbd class="shortcut-key">e</kbd>
                <span class="shortcut-desc">Edit current item (viewer)</span>
              </div>
            </div>
          </div>
        </div>
      </div>
    </Transition>
  </template>
  <template v-else>
    <router-view />
  </template>
  <ToastNotification />
</template>

<style>
.skip-link {
  position: absolute;
  top: -100%;
  left: 0.5rem;
  z-index: 9999;
  padding: 0.4rem 0.75rem;
  background: var(--fs-accent);
  color: var(--fs-text-on-action);
  border-radius: 0 0 4px 4px;
  font-size: 0.875rem;
  text-decoration: none;
  transition: top 0.1s;
}
.skip-link:focus {
  top: 0;
}

.app-shell {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}
.app-shell > .app-header {
  flex-shrink: 0;
}
.app-content {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
}
.app-content:has(.knowledge-root) {
  overflow: hidden;
}

/* Version footer */
.app-footer {
  flex-shrink: 0;
  text-align: center;
  padding: 0.2rem 0;
  font-size: 0.68rem;
  color: var(--fs-text-tertiary);
  opacity: 0.45;
  user-select: none;
  letter-spacing: 0.03em;
}

/* Shortcuts overlay */
.shortcuts-overlay {
  position: fixed;
  inset: 0;
  background: var(--fs-overlay);
  z-index: 9000;
  display: flex;
  align-items: center;
  justify-content: center;
}
.shortcuts-panel {
  background: var(--fs-surface-raised);
  border: 1px solid var(--fs-border-color);
  border-radius: var(--fs-radius-lg);
  box-shadow: 0 8px 32px var(--color-shadow);
  width: min(420px, 92vw);
  overflow: hidden;
}
.shortcuts-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1rem 0.75rem;
  border-bottom: 1px solid var(--fs-border-color);
}
.shortcuts-header h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--fs-text-primary);
}
.shortcuts-close {
  background: none;
  border: none;
  font-size: 1.4rem;
  line-height: 1;
  color: var(--fs-text-tertiary);
  cursor: pointer;
  padding: 0 0.25rem;
}
.shortcuts-close:hover {
  color: var(--fs-text-primary);
}
.shortcuts-body {
  padding: 0.75rem 1rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.shortcuts-section-title {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--fs-text-tertiary);
  margin-bottom: 0.4rem;
}
.shortcut-row {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0;
}
.shortcut-key {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.8rem;
  padding: 0.15rem 0.4rem;
  background: var(--fs-surface-raised);
  border: 1px solid var(--fs-border-color);
  border-bottom-width: 2px;
  border-radius: 4px;
  font-size: 0.78rem;
  font-family: ui-monospace, monospace;
  color: var(--fs-text-primary);
  white-space: nowrap;
  user-select: none;
}
.shortcut-key-sep {
  font-size: 0.78rem;
  color: var(--fs-text-tertiary);
}
.shortcut-desc {
  font-size: 0.875rem;
  color: var(--fs-text-primary);
  margin-left: 0.25rem;
}

/* Transition */
.shortcuts-fade-enter-active,
.shortcuts-fade-leave-active {
  transition: opacity 0.15s ease;
}
.shortcuts-fade-enter-from,
.shortcuts-fade-leave-to {
  opacity: 0;
}
</style>
