import { useEffect, useMemo, useState } from 'react';
import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
import { faHeadset } from '@fortawesome/pro-duotone-svg-icons';
import { TopBar } from '@/components/layout/top-bar';
import { Badge } from '@/components/base/badges/badges';
import { Button } from '@/components/base/buttons/button';
import { Table } from '@/components/application/table/table';
import { apiClient } from '@/lib/api-client';
import { useData } from '@/providers/data-provider';

type ActiveCall = {
    ucid: string;
    agentId: string;
    callerNumber: string;
    callType: string;
    startTime: string;
    status: 'active' | 'on-hold';
};

const formatDuration = (startTime: string): string => {
    const seconds = Math.max(0, Math.floor((Date.now() - new Date(startTime).getTime()) / 1000));
    const m = Math.floor(seconds / 60);
    const s = seconds % 60;
    return `${m}:${s.toString().padStart(2, '0')}`;
};

const KpiCard = ({ value, label }: { value: string | number; label: string }) => (
    <div className="flex flex-1 flex-col items-center justify-center rounded-xl border border-secondary bg-primary py-6">
        <p className="text-3xl font-bold text-primary">{value}</p>
        <p className="text-xs text-tertiary mt-1">{label}</p>
    </div>
);

export const LiveMonitorPage = () => {
    const [activeCalls, setActiveCalls] = useState<ActiveCall[]>([]);
    const [loading, setLoading] = useState(true);
    const [tick, setTick] = useState(0);
    const { leads } = useData();

    // Poll active calls every 5 seconds
    useEffect(() => {
        const fetchCalls = () => {
            apiClient.get<ActiveCall[]>('/api/supervisor/active-calls', { silent: true })
                .then(setActiveCalls)
                .catch(() => {})
                .finally(() => setLoading(false));
        };

        fetchCalls();
        const interval = setInterval(fetchCalls, 5000);
        return () => clearInterval(interval);
    }, []);

    // Tick every second to update duration counters
    useEffect(() => {
        const interval = setInterval(() => setTick(t => t + 1), 1000);
        return () => clearInterval(interval);
    }, []);

    const onHold = activeCalls.filter(c => c.status === 'on-hold').length;
    const avgDuration = useMemo(() => {
        if (activeCalls.length === 0) return '0:00';
        const totalSec = activeCalls.reduce((sum, c) => {
            return sum + Math.max(0, Math.floor((Date.now() - new Date(c.startTime).getTime()) / 1000));
        }, 0);
        const avg = Math.floor(totalSec / activeCalls.length);
        return `${Math.floor(avg / 60)}:${(avg % 60).toString().padStart(2, '0')}`;
    }, [activeCalls, tick]);

    // Match caller to lead
    const resolveCallerName = (phone: string): string | null => {
        if (!phone) return null;
        const clean = phone.replace(/\D/g, '');
        const lead = leads.find(l => {
            const lp = (l.contactPhone?.[0]?.number ?? '').replace(/\D/g, '');
            return lp && (lp.endsWith(clean) || clean.endsWith(lp));
        });
        if (lead) {
            return `${lead.contactName?.firstName ?? ''} ${lead.contactName?.lastName ?? ''}`.trim() || null;
        }
        return null;
    };

    return (
        <>
            <TopBar title="Live Call Monitor" subtitle="Listen, whisper, or barge into active calls" />

            <div className="flex flex-1 flex-col overflow-y-auto">
                {/* KPI Cards */}
                <div className="px-6 pt-5">
                    <div className="flex gap-4">
                        <KpiCard value={activeCalls.length} label="Active Calls" />
                        <KpiCard value={onHold} label="On Hold" />
                        <KpiCard value={avgDuration} label="Avg Duration" />
                    </div>
                </div>

                {/* Active Calls Table */}
                <div className="px-6 pt-6">
                    <h3 className="text-sm font-semibold text-secondary mb-3">Active Calls</h3>

                    {loading ? (
                        <div className="flex items-center justify-center py-12">
                            <p className="text-sm text-tertiary">Loading...</p>
                        </div>
                    ) : activeCalls.length === 0 ? (
                        <div className="flex flex-col items-center justify-center py-16 text-center rounded-xl border border-secondary bg-primary">
                            <FontAwesomeIcon icon={faHeadset} className="size-12 text-fg-quaternary mb-4" />
                            <p className="text-sm font-medium text-secondary">No active calls</p>
                            <p className="text-xs text-tertiary mt-1">Active calls will appear here in real-time</p>
                        </div>
                    ) : (
                        <Table size="sm">
                            <Table.Header>
                                <Table.Head label="Agent" isRowHeader />
                                <Table.Head label="Caller" />
                                <Table.Head label="Type" className="w-16" />
                                <Table.Head label="Duration" className="w-20" />
                                <Table.Head label="Status" className="w-24" />
                                <Table.Head label="Actions" className="w-48" />
                            </Table.Header>
                            <Table.Body items={activeCalls}>
                                {(call) => {
                                    const callerName = resolveCallerName(call.callerNumber);
                                    const typeLabel = call.callType === 'InBound' ? 'In' : 'Out';
                                    const typeColor = call.callType === 'InBound' ? 'blue' : 'brand';

                                    return (
                                        <Table.Row id={call.ucid}>
                                            <Table.Cell>
                                                <span className="text-sm font-medium text-primary">{call.agentId}</span>
                                            </Table.Cell>
                                            <Table.Cell>
                                                <div>
                                                    {callerName && <span className="text-sm font-medium text-primary block">{callerName}</span>}
                                                    <span className="text-xs text-tertiary">{call.callerNumber}</span>
                                                </div>
                                            </Table.Cell>
                                            <Table.Cell>
                                                <Badge size="sm" color={typeColor} type="pill-color">{typeLabel}</Badge>
                                            </Table.Cell>
                                            <Table.Cell>
                                                <span className="text-sm font-mono text-primary">{formatDuration(call.startTime)}</span>
                                            </Table.Cell>
                                            <Table.Cell>
                                                <Badge size="sm" color={call.status === 'on-hold' ? 'warning' : 'success'} type="pill-color">
                                                    {call.status}
                                                </Badge>
                                            </Table.Cell>
                                            <Table.Cell>
                                                <div className="flex items-center gap-1.5">
                                                    <Button size="sm" color="secondary" isDisabled title="Coming soon — pending Ozonetel API">Listen</Button>
                                                    <Button size="sm" color="secondary" isDisabled title="Coming soon — pending Ozonetel API">Whisper</Button>
                                                    <Button size="sm" color="primary-destructive" isDisabled title="Coming soon — requires supervisor SIP extension">Barge</Button>
                                                </div>
                                            </Table.Cell>
                                        </Table.Row>
                                    );
                                }}
                            </Table.Body>
                        </Table>
                    )}
                </div>

                {/* Monitoring hint */}
                {activeCalls.length > 0 && (
                    <div className="px-6 pt-6 pb-8">
                        <div className="flex flex-col items-center justify-center py-8 rounded-xl border border-secondary bg-secondary_alt text-center">
                            <FontAwesomeIcon icon={faHeadset} className="size-8 text-fg-quaternary mb-3" />
                            <p className="text-sm text-secondary">Select "Listen" on any active call to start monitoring</p>
                            <p className="text-xs text-tertiary mt-1">Agent will not be notified during listen mode</p>
                        </div>
                    </div>
                )}
            </div>
        </>
    );
};