import { WorkerOptions, defineAgent, llm, voice, VAD } from '@livekit/agents';
import * as google from '@livekit/agents-plugin-google';
import * as silero from '@livekit/agents-plugin-silero';
import { z } from 'zod';

// Platform GraphQL helper
const SIDECAR_URL = process.env.SIDECAR_URL ?? 'http://localhost:4100';
const PLATFORM_API_KEY = process.env.PLATFORM_API_KEY ?? '';

async function gql<T = any>(query: string, variables?: Record<string, unknown>): Promise<T | null> {
    if (!PLATFORM_API_KEY) return null;
    try {
        const res = await fetch(`${SIDECAR_URL}/graphql`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ${PLATFORM_API_KEY}` },
            body: JSON.stringify({ query, variables }),
        });
        const data = await res.json();
        if (data.errors) {
            console.error('[AGENT-GQL] Error:', data.errors[0]?.message);
            return null;
        }
        return data.data;
    } catch (err) {
        console.error('[AGENT-GQL] Failed:', err);
        return null;
    }
}

// Resolve a phone to a {leadId, patientId} pair via the sidecar's
// caller-resolution endpoint. Always returns populated IDs (creates
// placeholder lead+patient when none exist).
async function resolveCaller(phone: string): Promise<{ leadId: string; patientId: string; firstName: string; lastName: string; isNew: boolean } | null> {
    try {
        const res = await fetch(`${SIDECAR_URL}/api/caller/resolve`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ phone }),
        });
        if (!res.ok) {
            console.error('[AGENT-RESOLVE] Failed:', res.status, await res.text().catch(() => ''));
            return null;
        }
        return await res.json();
    } catch (err) {
        console.error('[AGENT-RESOLVE] Failed:', err);
        return null;
    }
}

// Hospital context — loaded on startup
let hospitalContext = {
    doctors: [] as Array<{ name: string; department: string; specialty: string; id: string }>,
    departments: [] as string[],
};

async function loadHospitalContext() {
    const data = await gql(`{ doctors(first: 20) { edges { node { id fullName { firstName lastName } department specialty } } } }`);
    if (data?.doctors?.edges) {
        hospitalContext.doctors = data.doctors.edges.map((e: any) => ({
            id: e.node.id,
            name: `Dr. ${e.node.fullName?.firstName ?? ''} ${e.node.fullName?.lastName ?? ''}`.trim(),
            department: e.node.department ?? '',
            specialty: e.node.specialty ?? '',
        }));
        hospitalContext.departments = [...new Set(hospitalContext.doctors.map(d => d.department))] as string[];
        console.log(`[LIVEKIT-AGENT] Loaded ${hospitalContext.doctors.length} doctors, ${hospitalContext.departments.length} departments`);
    } else {
        // Fallback
        hospitalContext.doctors = [
            { id: '', name: 'Dr. Arun Sharma', department: 'Cardiology', specialty: 'Interventional Cardiology' },
            { id: '', name: 'Dr. Rajesh Kumar', department: 'Orthopedics', specialty: 'Joint Replacement' },
            { id: '', name: 'Dr. Meena Patel', department: 'Gynecology', specialty: 'Reproductive Medicine' },
            { id: '', name: 'Dr. Lakshmi Reddy', department: 'General Medicine', specialty: 'Internal Medicine' },
            { id: '', name: 'Dr. Harpreet Singh', department: 'ENT', specialty: 'Head & Neck Surgery' },
        ];
        hospitalContext.departments = ['Cardiology', 'Orthopedics', 'Gynecology', 'General Medicine', 'ENT'];
        console.log('[LIVEKIT-AGENT] Using fallback doctor list');
    }
}

// ─── Tools ────────────────────────────────────────────────────────────

const lookupDoctor = llm.tool({
    description: 'Look up available doctors by department or specialty. Call this when the patient asks about a specific department or type of doctor.',
    parameters: z.object({
        department: z.string().nullable().describe('Department name like Cardiology, Orthopedics, ENT'),
        specialty: z.string().nullable().describe('Specialty or condition like joint pain, heart, ear'),
    }),
    execute: async ({ department, specialty }) => {
        let results = hospitalContext.doctors;
        if (department) {
            results = results.filter(d => d.department.toLowerCase().includes(department.toLowerCase()));
        }
        if (specialty) {
            results = results.filter(d =>
                d.specialty.toLowerCase().includes(specialty.toLowerCase()) ||
                d.department.toLowerCase().includes(specialty.toLowerCase()),
            );
        }
        if (results.length === 0) return 'No matching doctors found. Available departments: ' + hospitalContext.departments.join(', ');
        return results.map(d => `${d.name} — ${d.department} (${d.specialty})`).join('\n');
    },
});

const bookAppointment = llm.tool({
    description: 'Book an appointment for the caller. You MUST collect patient name, phone number, department, preferred date/time, and reason before calling this.',
    parameters: z.object({
        patientName: z.string().describe('Full name of the patient'),
        phoneNumber: z.string().describe('Patient phone number with country code'),
        department: z.string().describe('Department for the appointment'),
        doctorName: z.string().nullable().describe('Preferred doctor name if specified'),
        preferredDate: z.string().describe('Date in YYYY-MM-DD format or natural language'),
        preferredTime: z.string().describe('Time slot like 10:00 AM, morning, afternoon'),
        reason: z.string().describe('Reason for visit'),
    }),
    execute: async ({ patientName, phoneNumber, department, doctorName, preferredDate, preferredTime, reason }) => {
        console.log(`[LIVEKIT-AGENT] Booking: ${patientName} | ${phoneNumber} | ${department} | ${doctorName ?? 'any'} | ${preferredDate} ${preferredTime}`);

        // Parse date — try ISO format first, fallback to tomorrow
        let scheduledAt: string;
        try {
            const parsed = new Date(preferredDate);
            if (!isNaN(parsed.getTime())) {
                // Map time to hour
                const timeMap: Record<string, string> = { morning: '10:00', afternoon: '14:00', evening: '17:00' };
                const timeStr = timeMap[preferredTime.toLowerCase()] ?? preferredTime.replace(/\s*(AM|PM)/i, (_, p) => '');
                scheduledAt = new Date(`${parsed.toISOString().split('T')[0]}T${timeStr}:00`).toISOString();
            } else {
                scheduledAt = new Date(Date.now() + 86400000).toISOString(); // tomorrow
            }
        } catch {
            scheduledAt = new Date(Date.now() + 86400000).toISOString();
        }

        // Find matching doctor
        const doctor = doctorName
            ? hospitalContext.doctors.find(d => d.name.toLowerCase().includes(doctorName.toLowerCase()))
            : hospitalContext.doctors.find(d => d.department.toLowerCase().includes(department.toLowerCase()));

        // Create appointment on platform
        const result = await gql(
            `mutation($data: AppointmentCreateInput!) { createAppointment(data: $data) { id } }`,
            {
                data: {
                    name: `AI Booking — ${patientName} (${department})`,
                    scheduledAt,
                    status: 'SCHEDULED',
                    doctorName: doctor?.name ?? doctorName ?? 'To be assigned',
                    department,
                    reasonForVisit: reason,
                    ...((doctor as any)?.clinicId ? { clinicId: (doctor as any).clinicId } : {}),
                },
            },
        );

        // Resolve caller — if isNew, create Lead + Patient with the
        // AI-collected name; otherwise update the existing record.
        const cleanPhone = phoneNumber.replace(/[^0-9]/g, '').slice(-10);
        const resolved = await resolveCaller(cleanPhone);
        const fn = patientName.split(' ')[0];
        const ln = patientName.split(' ').slice(1).join(' ') || '';
        if (resolved?.isNew) {
            const p = await gql(
                `mutation($data: PatientCreateInput!) { createPatient(data: $data) { id } }`,
                { data: { fullName: { firstName: fn, lastName: ln }, phones: { primaryPhoneNumber: `+91${cleanPhone}` }, patientType: 'NEW' } },
            );
            const newPatientId = p?.createPatient?.id;
            await gql(
                `mutation($data: LeadCreateInput!) { createLead(data: $data) { id } }`,
                {
                    data: {
                        name: `AI — ${patientName}`,
                        contactName: { firstName: fn, lastName: ln },
                        contactPhone: { primaryPhoneNumber: `+91${cleanPhone}` },
                        source: 'PHONE',
                        status: 'APPOINTMENT_SET',
                        interestedService: department,
                        ...(newPatientId ? { patientId: newPatientId } : {}),
                    },
                },
            );
        } else if (resolved?.leadId) {
            await gql(
                `mutation($id: UUID!, $data: LeadUpdateInput!) { updateLead(id: $id, data: $data) { id } }`,
                {
                    id: resolved.leadId,
                    data: {
                        name: `AI — ${patientName}`,
                        contactName: { firstName: fn, lastName: ln },
                        source: 'PHONE',
                        status: 'APPOINTMENT_SET',
                        interestedService: department,
                    },
                },
            );
            if (resolved.patientId) {
                await gql(
                    `mutation($id: UUID!, $data: PatientUpdateInput!) { updatePatient(id: $id, data: $data) { id } }`,
                    { id: resolved.patientId, data: { fullName: { firstName: fn, lastName: ln } } },
                );
            }
        }

        const refNum = `GH-${Date.now().toString().slice(-6)}`;
        if (result?.createAppointment?.id) {
            console.log(`[LIVEKIT-AGENT] Appointment created: ${result.createAppointment.id}`);
            return `Appointment booked successfully! Reference number ${refNum}. ${patientName} is scheduled for ${department} on ${preferredDate} at ${preferredTime} with ${doctor?.name ?? 'an available doctor'}. A confirmation SMS will be sent to ${phoneNumber}.`;
        }
        return `I have noted the appointment request. Reference number ${refNum}. Our team will confirm the booking and send an SMS to ${phoneNumber}.`;
    },
});

const collectLeadInfo = llm.tool({
    description: 'Save the caller as a lead/enquiry when they are interested but not ready to book. Collect their name and phone number.',
    parameters: z.object({
        name: z.string().describe('Caller name'),
        phoneNumber: z.string().describe('Caller phone number'),
        interest: z.string().describe('What they are interested in or enquiring about'),
    }),
    execute: async ({ name, phoneNumber, interest }) => {
        console.log(`[LIVEKIT-AGENT] Lead: ${name} | ${phoneNumber} | ${interest}`);

        const cleanPhone = phoneNumber.replace(/[^0-9]/g, '').slice(-10);
        const resolved = await resolveCaller(cleanPhone);
        const fn = name.split(' ')[0];
        const ln = name.split(' ').slice(1).join(' ') || '';

        if (resolved?.isNew) {
            // Net-new caller — create Patient + Lead with the AI-collected name.
            const p = await gql(
                `mutation($data: PatientCreateInput!) { createPatient(data: $data) { id } }`,
                { data: { fullName: { firstName: fn, lastName: ln }, phones: { primaryPhoneNumber: `+91${cleanPhone}` }, patientType: 'NEW' } },
            );
            const newPatientId = p?.createPatient?.id;
            const created = await gql(
                `mutation($data: LeadCreateInput!) { createLead(data: $data) { id } }`,
                {
                    data: {
                        name: `AI Enquiry — ${name}`,
                        contactName: { firstName: fn, lastName: ln },
                        contactPhone: { primaryPhoneNumber: `+91${cleanPhone}` },
                        source: 'PHONE',
                        status: 'NEW',
                        interestedService: interest,
                        ...(newPatientId ? { patientId: newPatientId } : {}),
                    },
                },
            );
            console.log(`[LIVEKIT-AGENT] Lead created: ${created?.createLead?.id ?? 'none'} (patient ${newPatientId ?? 'none'})`);
        } else if (resolved?.leadId) {
            await gql(
                `mutation($id: UUID!, $data: LeadUpdateInput!) { updateLead(id: $id, data: $data) { id } }`,
                {
                    id: resolved.leadId,
                    data: {
                        name: `AI Enquiry — ${name}`,
                        contactName: { firstName: fn, lastName: ln },
                        source: 'PHONE',
                        status: 'NEW',
                        interestedService: interest,
                    },
                },
            );
            if (resolved.patientId) {
                await gql(
                    `mutation($id: UUID!, $data: PatientUpdateInput!) { updatePatient(id: $id, data: $data) { id } }`,
                    { id: resolved.patientId, data: { fullName: { firstName: fn, lastName: ln } } },
                );
            }
            console.log(`[LIVEKIT-AGENT] Lead updated: ${resolved.leadId} (patient ${resolved.patientId})`);
        }
        return `Thank you ${name}. I have noted your enquiry about ${interest}. One of our team members will call you back on ${phoneNumber} shortly.`;
    },
});

const transferToAgent = llm.tool({
    description: 'Transfer the call to a human agent. Use this when the caller explicitly asks to speak with a person, or when the query is too complex.',
    parameters: z.object({
        reason: z.string().describe('Why the caller needs a human agent'),
    }),
    execute: async ({ reason }) => {
        console.log(`[LIVEKIT-AGENT] Transfer requested: ${reason}`);
        // TODO: When SIP is connected, trigger Ozonetel transfer via sidecar API
        return 'I am transferring you to one of our agents now. Please hold for a moment. If no agent is available, someone will call you back within 15 minutes.';
    },
});

// ─── Agent ────────────────────────────────────────────────────────────

const hospitalAgent = new voice.Agent({
    instructions: `You are the AI receptionist for Global Hospital, Bangalore. Your name is Helix.

PERSONALITY:
- Warm, professional, and empathetic
- Speak clearly and at a moderate pace
- Use simple language — many callers may not be fluent in English
- Be concise — this is a phone call, not a chat
- Respond in the same language the caller uses (English, Hindi, Kannada)

CAPABILITIES:
- Answer questions about hospital departments, doctors, and specialties
- Book appointments — collect: name, phone, department, preferred date/time, reason
- Take messages and create enquiries for callback
- Transfer to a human agent when needed

HOSPITAL INFO:
- Global Hospital, Bangalore
- Open Monday to Saturday, 8 AM to 8 PM
- Emergency services available 24/7
- Departments: ${hospitalContext.departments.join(', ') || 'Cardiology, Orthopedics, Gynecology, General Medicine, ENT'}

RULES:
- Greet: "Hello, thank you for calling Global Hospital. This is Helix, how may I help you today?"
- If caller asks about pricing, say you will have the team call back with details
- Never give medical advice — always recommend consulting a doctor
- If the caller is in an emergency, tell them to visit the ER immediately or call 108
- Always confirm all details before booking an appointment
- End calls politely: "Thank you for calling Global Hospital. Have a good day!"
- If you cannot understand the caller, politely ask them to repeat`,
    llm: new google.beta.realtime.RealtimeModel({
        model: 'gemini-2.5-flash-native-audio-latest',
        voice: 'Aoede',
        temperature: 0.7,
    }),
    tools: { lookupDoctor, bookAppointment, collectLeadInfo, transferToAgent },
});

// ─── Entry Point ──────────────────────────────────────────────────────

export default defineAgent({
    prewarm: async (proc) => {
        proc.userData.vad = await silero.VAD.load();
        await loadHospitalContext();
    },
    entry: async (ctx) => {
        await ctx.connect();
        console.log(`[LIVEKIT-AGENT] Connected to room: ${ctx.room.name}`);

        const session = new voice.AgentSession({
            vad: ctx.proc.userData.vad as VAD,
        });

        await session.start({ agent: hospitalAgent, room: ctx.room });
        console.log('[LIVEKIT-AGENT] Voice session started');

        // Gemini Realtime handles greeting via instructions — no separate say() needed
    },
});

// CLI runner
if (require.main === module) {
    const options = new WorkerOptions({
        agent: __filename,
    });
    const { cli } = require('@livekit/agents');
    cli.runApp(options);
}