import { useMemo } from 'react';

import { cx } from '@/utils/cx';
import type { Lead } from '@/types/entities';

interface LeadFunnelProps {
    leads: Lead[];
}

type FunnelStage = {
    label: string;
    count: number;
    color: string;
};

export const LeadFunnel = ({ leads }: LeadFunnelProps) => {
    const stages = useMemo((): FunnelStage[] => {
        const total = leads.length;

        const contacted = leads.filter((lead) =>
            lead.leadStatus === 'CONTACTED' ||
            lead.leadStatus === 'QUALIFIED' ||
            lead.leadStatus === 'NURTURING' ||
            lead.leadStatus === 'APPOINTMENT_SET' ||
            lead.leadStatus === 'CONVERTED',
        ).length;

        const appointmentSet = leads.filter((lead) =>
            lead.leadStatus === 'APPOINTMENT_SET' ||
            lead.leadStatus === 'CONVERTED',
        ).length;

        const converted = leads.filter((lead) =>
            lead.leadStatus === 'CONVERTED',
        ).length;

        return [
            { label: 'Generated', count: total, color: 'bg-brand-600' },
            { label: 'Contacted', count: contacted, color: 'bg-brand-500' },
            { label: 'Appointment Set', count: appointmentSet, color: 'bg-brand-400' },
            { label: 'Converted', count: converted, color: 'bg-success-500' },
        ];
    }, [leads]);

    const maxCount = stages[0]?.count || 1;

    return (
        <div className="rounded-2xl border border-secondary bg-primary p-5">
            <h3 className="text-sm font-bold text-primary">Lead Funnel &middot; This Week</h3>

            <div className="mt-4 space-y-3">
                {stages.map((stage, index) => {
                    const widthPercent = maxCount > 0 ? (stage.count / maxCount) * 100 : 0;
                    const previousCount = index > 0 ? stages[index - 1].count : null;
                    const conversionRate =
                        previousCount !== null && previousCount > 0
                            ? ((stage.count / previousCount) * 100).toFixed(0)
                            : null;

                    return (
                        <div key={stage.label} className="space-y-1">
                            <div className="flex items-center justify-between">
                                <span className="text-xs font-medium text-secondary">{stage.label}</span>
                                <div className="flex items-center gap-2">
                                    <span className="text-sm font-bold text-primary">{stage.count}</span>
                                    {conversionRate !== null && (
                                        <span className="text-xs text-tertiary">({conversionRate}%)</span>
                                    )}
                                </div>
                            </div>
                            <div className="h-6 w-full overflow-hidden rounded-md bg-secondary">
                                <div
                                    className={cx('h-full rounded-md transition-all', stage.color)}
                                    style={{ width: `${Math.max(widthPercent, 2)}%` }}
                                />
                            </div>
                        </div>
                    );
                })}
            </div>
        </div>
    );
};