import React, {useEffect, useState} from "react";
import {HomepageAlertCard} from "./HomepageAlertCard.tsx";
import {Button} from "@/components/ui/button.tsx";
import axios from "axios";

interface TermixAlert {
    id: string;
    title: string;
    message: string;
    expiresAt: string;
    priority?: 'low' | 'medium' | 'high' | 'critical';
    type?: 'info' | 'warning' | 'error' | 'success';
    actionUrl?: string;
    actionText?: string;
}

interface AlertManagerProps {
    userId: string | null;
    loggedIn: boolean;
}

const apiBase = import.meta.env.DEV ? "http://localhost:8081/alerts" : "/alerts";

const API = axios.create({
    baseURL: apiBase,
});

export function HomepageAlertManager({userId, loggedIn}: AlertManagerProps): React.ReactElement {
    const [alerts, setAlerts] = useState<TermixAlert[]>([]);
    const [currentAlertIndex, setCurrentAlertIndex] = useState(0);
    const [loading, setLoading] = useState(false);
    const [error, setError] = useState<string | null>(null);

    useEffect(() => {
        if (loggedIn && userId) {
            fetchUserAlerts();
        }
    }, [loggedIn, userId]);

    const fetchUserAlerts = async () => {
        if (!userId) return;

        setLoading(true);
        setError(null);
        
        try {
            const response = await API.get(`/user/${userId}`);
            
            const userAlerts = response.data.alerts || [];

            const sortedAlerts = userAlerts.sort((a: TermixAlert, b: TermixAlert) => {
                const priorityOrder = { critical: 4, high: 3, medium: 2, low: 1 };
                const aPriority = priorityOrder[a.priority as keyof typeof priorityOrder] || 0;
                const bPriority = priorityOrder[b.priority as keyof typeof priorityOrder] || 0;
                
                if (aPriority !== bPriority) {
                    return bPriority - aPriority;
                }

                return new Date(a.expiresAt).getTime() - new Date(b.expiresAt).getTime();
            });

            setAlerts(sortedAlerts);
            setCurrentAlertIndex(0);
        } catch (err) {
            setError('Failed to load alerts');
        } finally {
            setLoading(false);
        }
    };

    const handleDismissAlert = async (alertId: string) => {
        if (!userId) return;
        
        try {
            const response = await API.post('/dismiss', {
                userId,
                alertId
            });

            setAlerts(prev => {
                const newAlerts = prev.filter(alert => alert.id !== alertId);
                return newAlerts;
            });

            setCurrentAlertIndex(prevIndex => {
                const newAlertsLength = alerts.length - 1;
                if (newAlertsLength === 0) return 0;
                if (prevIndex >= newAlertsLength) return Math.max(0, newAlertsLength - 1);
                return prevIndex;
            });
        } catch (err) {
            setError('Failed to dismiss alert');
        }
    };

    const handleCloseCurrentAlert = () => {
        if (alerts.length === 0) return;

        if (currentAlertIndex < alerts.length - 1) {
            setCurrentAlertIndex(currentAlertIndex + 1);
        } else {
            setAlerts([]);
            setCurrentAlertIndex(0);
        }
    };

    const handlePreviousAlert = () => {
        if (currentAlertIndex > 0) {
            setCurrentAlertIndex(currentAlertIndex - 1);
        }
    };

    const handleNextAlert = () => {
        if (currentAlertIndex < alerts.length - 1) {
            setCurrentAlertIndex(currentAlertIndex + 1);
        }
    };

    if (!loggedIn || !userId) {
        return null;
    }

    if (loading) {
        return (
            <div className="fixed top-4 right-4 z-50">
                <div className="bg-background border rounded-lg p-3 shadow-lg">
                    <div className="flex items-center gap-2">
                        <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-primary"></div>
                        <span className="text-sm text-muted-foreground">Loading alerts...</span>
                    </div>
                </div>
            </div>
        );
    }

    if (alerts.length === 0) {
        return null;
    }

    const currentAlert = alerts[currentAlertIndex];

    if (!currentAlert) {
        return null;
    }
    
    const priorityCounts = { critical: 0, high: 0, medium: 0, low: 0 };
    alerts.forEach(alert => {
        const priority = alert.priority || 'low';
        priorityCounts[priority as keyof typeof priorityCounts]++;
    });
    const hasMultipleAlerts = alerts.length > 1;

    return (
        <div className="fixed inset-0 flex items-center justify-center bg-background/80 backdrop-blur-sm z-10">
            <div className="relative w-full max-w-2xl mx-4">
                <HomepageAlertCard
                    alert={currentAlert}
                    onDismiss={handleDismissAlert}
                    onClose={handleCloseCurrentAlert}
                />

                {hasMultipleAlerts && (
                    <div className="absolute -bottom-16 left-1/2 transform -translate-x-1/2 flex items-center gap-2">
                        <Button
                            variant="outline"
                            size="sm"
                            onClick={handlePreviousAlert}
                            disabled={currentAlertIndex === 0}
                            className="h-8 px-3"
                        >
                            Previous
                        </Button>
                        <span className="text-sm text-muted-foreground">
                            {currentAlertIndex + 1} of {alerts.length}
                        </span>
                        <Button
                            variant="outline"
                            size="sm"
                            onClick={handleNextAlert}
                            disabled={currentAlertIndex === alerts.length - 1}
                            className="h-8 px-3"
                        >
                            Next
                        </Button>
                    </div>
                )}

                {error && (
                    <div className="absolute -bottom-20 left-1/2 transform -translate-x-1/2">
                        <div className="bg-destructive text-destructive-foreground px-3 py-1 rounded text-sm">
                            {error}
                        </div>
                    </div>
                )}
            </div>
        </div>
    );
}