<script setup lang="ts">
/**
 * @file discovery.vue
 * @description Course Discovery / Catalog Page matching Figma Desktop Layout.
 */

definePageMeta({
  layout: "default",
  middleware: "auth",
});

useHead({
  title: "รายการคอร์ส - e-Learning",
});

const { t, locale } = useI18n();
const { currentUser } = useAuth();
const $q = useQuasar();
const { fetchCategories } = useCategory();
const { fetchCourses, fetchCourseById, enrollCourse, getLocalizedText } = useCourse();

const showDetail = ref(false);
const searchQuery = ref("");
const activeCategory = ref<number | 'all'>('all');
const viewMode = ref<'grid' | 'list'>('grid');
const sortBy = ref('ยอดนิยม');
const sortOptions = ['ยอดนิยม', 'ล่าสุด', 'ราคาต่ำ-สูงสุด', 'ราคาสูง-ต่ำสุด'];

const categories = ref<any[]>([]);
const allCourses = ref<any[]>([]);  // เก็บคอร์สทั้งหมดเพื่อกรอง client-side
const selectedCourse = ref<any>(null);

const isLoading = ref(false);
const isLoadingDetail = ref(false);
const isEnrolling = ref(false);

const currentPage = ref(1);
const totalPages = ref(1);
const itemsPerPage = 12;

const getCategoryIcon = (name: any) => {
   const text = getLocalizedText(name) || ''
   if (text.includes('เว็บ') || text.includes('Web') || text.includes('โปรแกรม') || text.includes('Program') || text.includes('โค้ด')) return 'code'
   if (text.includes('ออกแบบ') || text.includes('Design') || text.includes('UI')) return 'palette'
   if (text.includes('ธุรกิจ') || text.includes('Business') || text.includes('การตลาด') || text.includes('Market')) return 'trending_up'
   if (text.includes('ข้อมูล') || text.includes('Data') || text.includes('วิเคราะ') || text.includes('Sci')) return 'storage'
   return 'category'
}

const formatPrice = (course: any) => {
    if (course.is_free) return 'ฟรี';
    if (!course.price) return 'ฟรี';
    return `฿${parseFloat(course.price).toLocaleString()}`;
};

const getInstructorName = (course: any) => {
    let user = null;
    if (course.instructors && course.instructors.length > 0) {
        const primary = course.instructors.find((i: any) => i.is_primary);
        user = primary ? primary.user : course.instructors[0].user;
    } else {
        user = course.creator || course.instructor;
    }
    
    if (user?.profile?.first_name) {
        return `${user.profile.first_name} ${user.profile.last_name || ''}`.trim();
    }
    if (user?.first_name) {
        return `${user.first_name} ${user.last_name || ''}`.trim();
    }
    return user?.username || 'ผู้สอน';
};

const loadCategories = async () => {
  const res = await fetchCategories();
  if (res.success) categories.value = res.data || [];
};

const loadCourses = async () => {
  isLoading.value = true;

  // โหลดคอร์สทั้งหมดครั้งเดียว (limit สูงๆ เพื่อ client-side filter)
  const res = await fetchCourses({
    limit: 500,
    forceRefresh: true,
  });

  if (res.success) {
    allCourses.value = (res.data || []).map(c => {
       const cat = categories.value.find(cat => cat.id === c.category_id);
       return {
          ...c,
          category_name: cat ? getLocalizedText(cat.name) : '',
          instructor_name: getInstructorName(c),
          formatted_price: formatPrice(c),
          rating: c.rating || '4.9',
          reviews_count: c.total_lessons ? c.total_lessons * 123 : Math.floor(Math.random() * 2000) + 100
       }
    });
  }
  isLoading.value = false;
};

// Computed: กรองคอร์สแบบ real-time ตาม searchQuery + activeCategory
const filteredCourses = computed(() => {
  let result = allCourses.value;

  // กรองตามหมวดหมู่
  if (activeCategory.value !== 'all') {
    result = result.filter(c => c.category_id === activeCategory.value);
  }

  // กรองตามคำค้นหา (ค้นจากชื่อทั้ง th และ en)
  if (searchQuery.value.trim()) {
    const query = searchQuery.value.trim().toLowerCase();
    result = result.filter(c => {
      const titleTh = (c.title?.th || '').toLowerCase();
      const titleEn = (c.title?.en || '').toLowerCase();
      const titleStr = (typeof c.title === 'string' ? c.title : '').toLowerCase();
      return titleTh.includes(query) || titleEn.includes(query) || titleStr.includes(query);
    });
  }

  return result;
});

const selectCourse = async (id: number) => {
  isLoadingDetail.value = true;
  selectedCourse.value = null;
  showDetail.value = true;
  const res = await fetchCourseById(id);
  if (res.success) selectedCourse.value = res.data;
  isLoadingDetail.value = false;
};

const handleEnroll = async (id: number) => {
  if (isEnrolling.value) return;
  isEnrolling.value = true;
  const res = await enrollCourse(id);
  if (res.success) {
    return navigateTo("/dashboard/my-courses?enrolled=true");
  } else {
    $q.notify({
      type: "negative",
      message: res.error || t("enrollment.error"),
      position: "top",
      timeout: 3000,
      actions: [{ icon: "close", color: "white" }],
    });
  }
  isEnrolling.value = false;
};

watch(
  activeCategory,
  () => {
    currentPage.value = 1;
  }
);


onMounted(async () => {
  await loadCategories();
  
  // Check if category_id or course_id is in query
  const route = useRoute();
  if (route.query.category_id) {
    activeCategory.value = Number(route.query.category_id);
  }
  
  await loadCourses();

  if (route.query.course_id) {
    selectCourse(Number(route.query.course_id));
  }
});
</script>

<template>
  <div class="bg-[#F8F9FA] dark:bg-[#020617] min-h-screen p-4 md:p-8 transition-colors duration-300">
    <div class="max-w-[1240px] mx-auto">
        <!-- ส่วนของการค้นหาคอร์ส (Catalog View) -->
        <div v-if="!showDetail" class="bg-white dark:!bg-slate-900 rounded-[2rem] p-6 md:p-8 shadow-[0_2px_15px_rgb(0,0,0,0.02)] border border-slate-100 dark:!border-slate-800 min-h-[500px] mb-12 transition-colors">
            
            <!-- ส่วนหัวและการค้นหา -->
            <div class="flex flex-col md:flex-row md:items-center justify-between gap-6 mb-8">
               <h2 class="text-[1.35rem] font-bold text-slate-900 dark:text-[#f8fafc] tracking-tight">{{ $t('discovery.title') }}</h2>
               <div class="flex flex-wrap sm:flex-nowrap items-center gap-3 w-full md:w-auto">
                  <div class="relative w-full sm:w-[260px] flex-1">
                     <q-icon name="search" size="18px" class="absolute left-4 top-1/2 -translate-y-1/2 text-slate-400" />
                     <input v-model="searchQuery" class="w-full bg-slate-100 dark:bg-slate-800 border-none rounded-xl py-2.5 pl-11 pr-4 text-sm font-medium text-slate-700 dark:text-slate-200 placeholder:text-slate-400 focus:ring-2 focus:ring-blue-500/20 outline-none transition-all shadow-sm" :placeholder="$t('discovery.searchPlaceholder')" />
                  </div>
                  <div class="flex items-center gap-2 shrink-0">
                     <button @click="viewMode = 'grid'" :class="viewMode === 'grid' ? 'bg-[#E9EFFD] dark:!bg-blue-900/40 text-[#3B6BE8] dark:!text-blue-400 border-[#3B6BE8] dark:!border-blue-400' : 'bg-white border-slate-200 dark:!bg-slate-800 dark:!border-slate-700 text-slate-400 dark:!text-slate-300 hover:bg-slate-50 dark:hover:!bg-slate-700'" class="w-[42px] h-[42px] flex items-center justify-center rounded-xl border transition-colors outline-none"><q-icon name="grid_view" size="20px" /></button>
                     <button @click="viewMode = 'list'" :class="viewMode === 'list' ? 'bg-[#E9EFFD] dark:!bg-blue-900/40 text-[#3B6BE8] dark:!text-blue-400 border-[#3B6BE8] dark:!border-blue-400' : 'bg-white border-slate-200 dark:!bg-slate-800 dark:!border-slate-700 text-slate-400 dark:!text-slate-300 hover:bg-slate-50 dark:hover:!bg-slate-700'" class="w-[42px] h-[42px] flex items-center justify-center rounded-xl border transition-colors outline-none"><q-icon name="view_list" size="20px" /></button>
                  </div>
               </div>
            </div>

            <!-- Filters Category -->
            <div class="flex flex-col xl:flex-row xl:items-center justify-between gap-4 mb-10 w-full relative">
                <!-- Figma Style: Separate pill buttons -->
                <div class="flex flex-wrap items-center gap-3 w-full xl:w-auto">
                   <button 
                     @click="activeCategory = 'all'"
                     :class="activeCategory === 'all' ? 'bg-[#E9EFFD] dark:!bg-blue-900/40 text-[#3B6BE8] dark:!text-blue-400 border-transparent font-bold' : 'bg-white dark:!bg-slate-800 border-slate-200 dark:!border-slate-700 text-slate-800 dark:!text-slate-200 hover:border-slate-300 dark:hover:!border-slate-600 font-medium'"
                     class="px-5 py-2.5 rounded-full border text-[13px] sm:text-[14px] flex items-center justify-center gap-2 transition-all outline-none">
                     <q-icon name="check_circle_outline" size="18px" :class="activeCategory === 'all' ? 'text-[#3B6BE8] dark:!text-blue-400' : 'text-slate-400 dark:!text-slate-400'"/> {{ $t('discovery.allCategory') }}
                   </button>
                   
                   <button 
                     v-for="cat in categories" :key="cat.id"
                     @click="activeCategory = cat.id"
                     :class="activeCategory === cat.id ? 'bg-[#E9EFFD] dark:!bg-blue-900/40 text-[#3B6BE8] dark:!text-blue-400 border-transparent font-bold' : 'bg-white dark:!bg-slate-800 border-slate-200 dark:!border-slate-700 text-slate-800 dark:!text-slate-200 hover:border-slate-300 dark:hover:!border-slate-600 font-medium'"
                     class="px-5 py-2.5 rounded-full border text-[13px] sm:text-[14px] flex items-center justify-center gap-2 transition-all outline-none">
                     <q-icon :name="getCategoryIcon(cat.name)" size="18px" :class="activeCategory === cat.id ? 'text-[#3B6BE8] dark:!text-blue-400' : 'text-slate-600 dark:!text-slate-400'"/>
                     {{ getLocalizedText(cat.name) }}
                   </button>
                </div>
                

            </div>

            <!-- Loader -->
            <div v-if="isLoading" class="flex justify-center py-24">
               <q-spinner size="3rem" color="primary" />
            </div>

            <div v-else-if="filteredCourses.length > 0">
               <!-- GRID VIEW -->
               <div v-if="viewMode === 'grid'" class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-6">
                  <div v-for="course in filteredCourses" :key="course.id" class="flex flex-col rounded-[1.5rem] bg-white dark:!bg-slate-900 border border-slate-100 dark:!border-slate-800 overflow-hidden shadow-[0_2px_10px_rgb(0,0,0,0.03)] hover:shadow-[0_8px_30px_rgb(0,0,0,0.08)] transition-all duration-300 group cursor-pointer" @click="selectCourse(course.id)">
                     <!-- Thumbnail -->
                     <div class="relative w-full aspect-[16/10] bg-slate-100 dark:bg-slate-800 overflow-hidden">
                        <img :src="course.thumbnail_url" class="w-full h-full object-cover group-hover:scale-105 transition-transform duration-500" />
                        <div v-if="course.category_name" class="absolute top-3 left-3 bg-white/95 dark:bg-slate-900/95 backdrop-blur-md text-[#3B6BE8] dark:text-blue-400 font-bold text-[10px] px-3.5 py-1 rounded-full shadow-sm" style="border-radius: 9999px; padding: 4px 12px;">
                           {{ course.category_name }}
                        </div>
                     </div>
                     
                     <!-- Body -->
                     <div class="p-5 flex flex-col flex-1">
                        <h3 class="font-bold text-slate-900 dark:text-[#f8fafc] text-[15px] leading-snug line-clamp-2 mb-2 group-hover:text-blue-600 dark:group-hover:text-blue-400 transition-colors">{{ getLocalizedText(course.title) }}</h3>
                        

                        
                        <div class="mt-auto flex items-center justify-between">
                            <div class="font-[900] text-[18px]" :class="course.is_free ? 'text-green-500' : 'text-[#2563EB] dark:text-blue-400'">
                                {{ course.formatted_price }}
                            </div>
                            <button class="w-[38px] h-[38px] rounded-full bg-slate-50 dark:!bg-slate-800 text-slate-400 dark:!text-slate-300 flex items-center justify-center hover:bg-blue-50 hover:text-blue-600 dark:hover:!bg-slate-700 dark:hover:!text-blue-400 border border-slate-100 dark:!border-slate-700 transition-colors shadow-sm outline-none">
                                <q-icon name="visibility" size="18px" />
                            </button>
                        </div>
                     </div>
                  </div>
               </div>

               <!-- LIST VIEW -->
               <div v-else class="flex flex-col gap-5">
                  <div v-for="course in filteredCourses" :key="course.id" class="flex flex-col sm:flex-row rounded-[1.5rem] bg-white dark:!bg-slate-900 border border-slate-100 dark:!border-slate-800 p-3 sm:p-4 gap-4 sm:gap-6 shadow-sm hover:shadow-[0_8px_30px_rgb(0,0,0,0.06)] transition-all duration-300 group cursor-pointer" @click="selectCourse(course.id)">
                     <div class="relative w-full sm:w-[260px] aspect-[16/10] sm:aspect-auto sm:h-[160px] rounded-[1rem] bg-slate-100 dark:bg-slate-800 overflow-hidden shrink-0">
                        <img :src="course.thumbnail_url" class="w-full h-full object-cover group-hover:scale-105 transition-transform duration-500" />
                        <div v-if="course.category_name" class="absolute top-3 left-3 bg-white/95 dark:bg-slate-900/95 backdrop-blur-md text-[#3B6BE8] dark:text-blue-400 font-bold text-[10px] px-3.5 py-1.5 rounded-full shadow-sm" style="border-radius: 9999px; padding: 4px 12px;">
                           {{ course.category_name }}
                        </div>
                     </div>
                     <div class="flex flex-col flex-1 py-1">
                        <div class="flex-1">
                            <h3 class="font-bold text-slate-900 dark:text-[#f8fafc] text-[16px] md:text-[18px] leading-snug line-clamp-2 md:line-clamp-1 mb-2 group-hover:text-blue-600 dark:group-hover:text-blue-400 transition-colors">{{ getLocalizedText(course.title) }}</h3>

                        </div>
                        <div class="mt-4 sm:mt-auto flex items-center justify-between">
                            <div class="font-[900] text-[20px]" :class="course.is_free ? 'text-green-500' : 'text-[#2563EB] dark:text-blue-400'">
                                {{ course.formatted_price }}
                            </div>
                            <button class="px-6 py-2 rounded-full bg-slate-50 text-slate-600 dark:!bg-slate-800 dark:!text-slate-300 font-bold text-[13px] flex items-center gap-2 hover:bg-blue-50 hover:text-blue-600 dark:hover:!bg-slate-700 dark:hover:!text-blue-400 border border-slate-100 dark:!border-slate-700 transition-colors">
                                <q-icon name="visibility" size="16px" /> {{ $t('discovery.viewDetails') }}
                            </button>
                        </div>
                     </div>
                  </div>
               </div>

               <!-- Pagination -->
               <div v-if="totalPages > 1" class="flex justify-center pt-8 pb-4">
                  <q-pagination v-model="currentPage" :max="totalPages" :max-pages="6" boundary-numbers direction-links color="primary" flat active-design="unelevated" active-color="primary" @update:model-value="loadCourses"/>
               </div>
            </div>

            <!-- Empty State -->
            <div v-else class="flex flex-col items-center justify-center py-20 bg-white dark:!bg-slate-900/50 rounded-3xl border border-dashed border-slate-200 dark:!border-slate-800">
               <q-icon name="search_off" size="64px" class="text-slate-300 dark:text-slate-600 mb-4" />
               <h3 class="text-xl font-bold text-slate-900 dark:!text-white mb-2">{{ $t("discovery.emptyTitle") }}</h3>
               <p class="text-slate-500 dark:text-slate-400 text-center max-w-md">{{ $t("discovery.emptyDesc") }}</p>
               <button class="mt-6 font-bold text-blue-600 hover:text-blue-700 transition-colors" @click="searchQuery = ''; activeCategory = 'all';">
                  {{ $t("discovery.showAll") }}
               </button>
            </div>
        </div>

        <!-- COURSE DETAIL VIEW: Detailed information about a specific course -->
        <div v-else>
          <button @click="showDetail = false" class="inline-flex items-center gap-2 text-slate-600 dark:text-white hover:text-blue-600 dark:hover:text-blue-300 mb-6 transition-all font-black text-lg md:text-xl group">
            <q-icon name="arrow_back" size="24px" class="transition-transform group-hover:-translate-x-1" />
            {{ $t("discovery.backToCatalog") }}
          </button>
          <div v-if="isLoadingDetail" class="flex justify-center py-20"><q-spinner size="3rem" color="primary" /></div>
          <CourseDetailView v-else-if="selectedCourse" :course="selectedCourse" :user="currentUser" @back="showDetail = false" @enroll="handleEnroll"/>
        </div>
    </div>
  </div>
</template>

<style scoped>
/* Disable default scrollbar for filter container */
.scrollbar-hide::-webkit-scrollbar {
    display: none;
}
.scrollbar-hide {
    -ms-overflow-style: none;
    scrollbar-width: none;
}
</style>
