/**
 * Offline Indicator Component
 *
 * Displays network status and sync state in the header.
 * Shows: Online, Offline, Syncing states with appropriate colors.
 */

const { ref, computed, onMounted, onUnmounted, watch } = Vue;

export default {
    name: 'OfflineIndicator',

    props: {
        // Whether offline mode is enabled in settings
        offlineModeEnabled: {
            type: Boolean,
            default: false
        },
        // Number of pending changes
        pendingCount: {
            type: Number,
            default: 0
        },
        // Whether sync is currently running
        isSyncing: {
            type: Boolean,
            default: false
        },
        // Data freshness level: 'fresh', 'stale', 'old', 'unknown'
        freshness: {
            type: String,
            default: 'unknown'
        }
    },

    emits: ['sync-click'],

    setup(props, { emit }) {
        const isOnline = ref(navigator.onLine);

        // Update online status
        const updateOnlineStatus = () => {
            isOnline.value = navigator.onLine;
        };

        onMounted(() => {
            window.addEventListener('online', updateOnlineStatus);
            window.addEventListener('offline', updateOnlineStatus);
        });

        onUnmounted(() => {
            window.removeEventListener('online', updateOnlineStatus);
            window.removeEventListener('offline', updateOnlineStatus);
        });

        // Computed display state
        const displayState = computed(() => {
            if (!props.offlineModeEnabled) {
                return isOnline.value ? 'online' : 'offline-no-cache';
            }

            if (props.isSyncing) {
                return 'syncing';
            }

            if (!isOnline.value) {
                return 'offline';
            }

            if (props.pendingCount > 0) {
                return 'pending';
            }

            return 'online';
        });

        // Status text
        const statusText = computed(() => {
            switch (displayState.value) {
                case 'syncing':
                    return 'Synchronisiere...';
                case 'offline':
                    return 'Offline';
                case 'offline-no-cache':
                    return 'Keine Verbindung';
                case 'pending':
                    return `${props.pendingCount} ausstehend`;
                case 'online':
                    return props.offlineModeEnabled ? 'Synchronisiert' : '';
                default:
                    return '';
            }
        });

        // Status icon
        const statusIcon = computed(() => {
            switch (displayState.value) {
                case 'syncing':
                    return 'sync';
                case 'offline':
                case 'offline-no-cache':
                    return 'cloud-off';
                case 'pending':
                    return 'cloud-upload';
                case 'online':
                    return 'cloud-check';
                default:
                    return 'cloud';
            }
        });

        // Status color classes
        const statusClasses = computed(() => {
            switch (displayState.value) {
                case 'syncing':
                    return 'bg-blue-100 text-blue-700 dark:bg-blue-900 dark:text-blue-300';
                case 'offline':
                    return 'bg-orange-100 text-orange-700 dark:bg-orange-900 dark:text-orange-300';
                case 'offline-no-cache':
                    return 'bg-red-100 text-red-700 dark:bg-red-900 dark:text-red-300';
                case 'pending':
                    return 'bg-yellow-100 text-yellow-700 dark:bg-yellow-900 dark:text-yellow-300';
                case 'online':
                    return 'bg-green-100 text-green-700 dark:bg-green-900 dark:text-green-300';
                default:
                    return 'bg-gray-100 text-gray-700 dark:bg-gray-800 dark:text-gray-300';
            }
        });

        // Freshness indicator color
        const freshnessColor = computed(() => {
            switch (props.freshness) {
                case 'fresh':
                    return 'bg-green-500';
                case 'stale':
                    return 'bg-yellow-500';
                case 'old':
                    return 'bg-red-500';
                default:
                    return 'bg-gray-400';
            }
        });

        // Click handler
        const handleClick = () => {
            if (isOnline.value && props.pendingCount > 0) {
                emit('sync-click');
            }
        };

        // Should show (only show if offline mode enabled or offline)
        const shouldShow = computed(() => {
            return props.offlineModeEnabled || !isOnline.value;
        });

        return {
            isOnline,
            displayState,
            statusText,
            statusIcon,
            statusClasses,
            freshnessColor,
            handleClick,
            shouldShow
        };
    },

    template: `
        <div
            v-if="shouldShow"
            :class="[
                'inline-flex items-center gap-1.5 px-2 py-1 rounded-full text-xs font-medium transition-all',
                statusClasses,
                (isOnline && pendingCount > 0) ? 'cursor-pointer hover:opacity-80' : ''
            ]"
            @click="handleClick"
        >
            <!-- Syncing spinner -->
            <svg v-if="displayState === 'syncing'" class="w-3.5 h-3.5 animate-spin" fill="none" viewBox="0 0 24 24">
                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
            </svg>

            <!-- Cloud off icon (offline) -->
            <svg v-else-if="displayState === 'offline' || displayState === 'offline-no-cache'" class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M3 3l18 18M10.5 6.5A7.5 7.5 0 0118 12m-3.5 4.5H6a4 4 0 01-.5-7.97"/>
            </svg>

            <!-- Cloud upload icon (pending) -->
            <svg v-else-if="displayState === 'pending'" class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M7 16a4 4 0 01-.88-7.903A5 5 0 1115.9 6L16 6a5 5 0 011 9.9M15 13l-3-3m0 0l-3 3m3-3v12"/>
            </svg>

            <!-- Cloud check icon (synced) -->
            <svg v-else-if="displayState === 'online'" class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M3 15a4 4 0 004 4h9a5 5 0 10-.1-9.999 5.002 5.002 0 10-9.78 2.096A4.001 4.001 0 003 15z"/>
                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 12l2 2 4-4"/>
            </svg>

            <!-- Status text -->
            <span v-if="statusText">{{ statusText }}</span>

            <!-- Freshness dot (when showing cached data) -->
            <span
                v-if="offlineModeEnabled && displayState !== 'syncing'"
                :class="['w-1.5 h-1.5 rounded-full', freshnessColor]"
                :title="freshness === 'fresh' ? 'Aktuell' : freshness === 'stale' ? 'Etwas älter' : freshness === 'old' ? 'Veraltet' : ''"
            ></span>
        </div>
    `
};