import { Injectable, Logger, OnModuleInit } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { PlatformGraphqlService } from '../platform/platform-graphql.service';
import { OzonetelAgentService } from '../ozonetel/ozonetel-agent.service';

// Ozonetel sends all timestamps in IST — convert to UTC for storage
export function istToUtc(istDateStr: string | null): string | null {
    if (!istDateStr) return null;
    const d = new Date(istDateStr);
    if (isNaN(d.getTime())) return null;
    d.setMinutes(d.getMinutes() - 330); // IST is UTC+5:30
    return d.toISOString();
}

// Normalize phone to +91XXXXXXXXXX format
export function normalizePhone(raw: string): string {
    let digits = raw.replace(/[^0-9]/g, '');
    // Strip leading country code variations: 0091, 91, 0
    if (digits.startsWith('0091')) digits = digits.slice(4);
    else if (digits.startsWith('91') && digits.length > 10) digits = digits.slice(2);
    else if (digits.startsWith('0') && digits.length > 10) digits = digits.slice(1);
    return `+91${digits.slice(-10)}`;
}

@Injectable()
export class MissedQueueService implements OnModuleInit {
    private readonly logger = new Logger(MissedQueueService.name);
    private readonly pollIntervalMs: number;
    private readonly processedUcids = new Set<string>();
    private assignmentMutex = false;

    constructor(
        private readonly config: ConfigService,
        private readonly platform: PlatformGraphqlService,
        private readonly ozonetel: OzonetelAgentService,
    ) {
        this.pollIntervalMs = this.config.get<number>('missedQueue.pollIntervalMs', 30000);
    }

    onModuleInit() {
        this.logger.log(`Starting missed call ingestion polling every ${this.pollIntervalMs}ms`);
        setInterval(() => this.ingest().catch(err => this.logger.error('Ingestion failed', err)), this.pollIntervalMs);
    }

    async ingest(): Promise<{ created: number; updated: number }> {
        let created = 0;
        let updated = 0;

        // Ozonetel fromTime/toTime use HH:MM:SS format (time of day, filters within current day)
        const now = new Date();
        const fiveMinAgo = new Date(now.getTime() - 5 * 60 * 1000);
        const toHHMMSS = (d: Date) => d.toTimeString().slice(0, 8);

        let abandonCalls: any[];
        try {
            abandonCalls = await this.ozonetel.getAbandonCalls({ fromTime: toHHMMSS(fiveMinAgo), toTime: toHHMMSS(now) });
        } catch (err) {
            this.logger.warn(`Failed to fetch abandon calls: ${err}`);
            return { created: 0, updated: 0 };
        }

        if (!abandonCalls?.length) return { created: 0, updated: 0 };

        for (const call of abandonCalls) {
            const ucid = call.monitorUCID;
            if (!ucid || this.processedUcids.has(ucid)) continue;
            this.processedUcids.add(ucid);

            const phone = normalizePhone(call.callerID || '');
            if (!phone || phone.length < 13) continue;

            const did = call.did || '';
            const callTime = istToUtc(call.callTime) ?? new Date().toISOString();

            try {
                // Look up lead by phone number — strip +91 prefix for flexible matching
                const phoneDigits = phone.replace(/^\+91/, '');
                let leadId: string | null = null;
                let leadName: string | null = null;
                try {
                    const leadResult = await this.platform.query<any>(
                        `{ leads(first: 1, filter: {
                            contactPhone: { primaryPhoneNumber: { like: "%${phoneDigits}" } }
                        }) { edges { node { id contactName { firstName lastName } patientId } } } }`,
                    );
                    const matchedLead = leadResult?.leads?.edges?.[0]?.node;
                    if (matchedLead) {
                        leadId = matchedLead.id;
                        const fn = matchedLead.contactName?.firstName ?? '';
                        const ln = matchedLead.contactName?.lastName ?? '';
                        leadName = `${fn} ${ln}`.trim() || null;
                        this.logger.log(`Matched missed call ${phone} → lead ${leadId} (${leadName})`);
                    }
                } catch (err) {
                    this.logger.warn(`Lead lookup failed for ${phone}: ${err}`);
                }

                const existing = await this.platform.query<any>(
                    `{ calls(first: 1, filter: {
                        callbackstatus: { eq: PENDING_CALLBACK },
                        callerNumber: { primaryPhoneNumber: { eq: "${phone}" } }
                    }) { edges { node { id missedcallcount } } } }`,
                );

                const existingNode = existing?.calls?.edges?.[0]?.node;

                if (existingNode) {
                    const newCount = (existingNode.missedcallcount || 1) + 1;
                    const updateParts = [
                        `missedcallcount: ${newCount}`,
                        `startedAt: "${callTime}"`,
                        `callsourcenumber: "${did}"`,
                    ];
                    if (leadId) updateParts.push(`leadId: "${leadId}"`);
                    if (leadName) updateParts.push(`leadName: "${leadName}"`);
                    await this.platform.query<any>(
                        `mutation { updateCall(id: "${existingNode.id}", data: { ${updateParts.join(', ')} }) { id } }`,
                    );
                    updated++;
                    this.logger.log(`Dedup missed call ${phone}: count now ${newCount}${leadName ? ` (${leadName})` : ''}`);
                } else {
                    const dataParts = [
                        `callStatus: MISSED`,
                        `direction: INBOUND`,
                        `callerNumber: { primaryPhoneNumber: "${phone}", primaryPhoneCallingCode: "+91" }`,
                        `callsourcenumber: "${did}"`,
                        `callbackstatus: PENDING_CALLBACK`,
                        `missedcallcount: 1`,
                        `startedAt: "${callTime}"`,
                    ];
                    if (leadId) dataParts.push(`leadId: "${leadId}"`);
                    if (leadName) dataParts.push(`leadName: "${leadName}"`);
                    await this.platform.query<any>(
                        `mutation { createCall(data: { ${dataParts.join(', ')} }) { id } }`,
                    );
                    created++;
                    this.logger.log(`Created missed call record for ${phone}${leadName ? ` → ${leadName}` : ''}`);
                }
            } catch (err) {
                this.logger.warn(`Failed to process abandon call ${ucid}: ${err}`);
            }
        }

        // Trim processedUcids to prevent unbounded growth
        if (this.processedUcids.size > 500) {
            const arr = Array.from(this.processedUcids);
            this.processedUcids.clear();
            arr.slice(-200).forEach(u => this.processedUcids.add(u));
        }

        if (created || updated) this.logger.log(`Ingestion: ${created} created, ${updated} updated`);
        return { created, updated };
    }

    async assignNext(agentName: string): Promise<any | null> {
        if (this.assignmentMutex) return null;
        this.assignmentMutex = true;

        try {
            // Find oldest unassigned PENDING_CALLBACK call (empty agentName)
            let result = await this.platform.query<any>(
                `{ calls(first: 1, filter: {
                    callbackstatus: { eq: PENDING_CALLBACK },
                    agentName: { eq: "" }
                }, orderBy: [{ startedAt: AscNullsLast }]) {
                    edges { node {
                        id callerNumber { primaryPhoneNumber }
                        startedAt callsourcenumber missedcallcount
                    } }
                } }`,
            );

            let call = result?.calls?.edges?.[0]?.node;

            // Also check for null agentName
            if (!call) {
                result = await this.platform.query<any>(
                    `{ calls(first: 1, filter: {
                        callbackstatus: { eq: PENDING_CALLBACK },
                        agentName: { is: NULL }
                    }, orderBy: [{ startedAt: AscNullsLast }]) {
                        edges { node {
                            id callerNumber { primaryPhoneNumber }
                            startedAt callsourcenumber missedcallcount
                        } }
                    } }`,
                );
                call = result?.calls?.edges?.[0]?.node;
            }

            if (!call) return null;

            await this.platform.query<any>(
                `mutation { updateCall(id: "${call.id}", data: { agentName: "${agentName}" }) { id } }`,
            );
            this.logger.log(`Assigned missed call ${call.id} to ${agentName}`);
            return call;
        } catch (err) {
            this.logger.warn(`Assignment failed: ${err}`);
            return null;
        } finally {
            this.assignmentMutex = false;
        }
    }

    async updateStatus(callId: string, status: string, authHeader: string): Promise<any> {
        const validStatuses = ['PENDING_CALLBACK', 'CALLBACK_ATTEMPTED', 'CALLBACK_COMPLETED', 'INVALID', 'WRONG_NUMBER'];
        if (!validStatuses.includes(status)) {
            throw new Error(`Invalid status: ${status}. Must be one of: ${validStatuses.join(', ')}`);
        }

        const dataParts: string[] = [`callbackstatus: ${status}`];
        if (status === 'CALLBACK_ATTEMPTED') {
            dataParts.push(`callbackattemptedat: "${new Date().toISOString()}"`);
        }

        return this.platform.queryWithAuth<any>(
            `mutation { updateCall(id: "${callId}", data: { ${dataParts.join(', ')} }) { id callbackstatus callbackattemptedat } }`,
            undefined,
            authHeader,
        );
    }

    async getMissedQueue(agentName: string, authHeader: string): Promise<{
        pending: any[];
        attempted: any[];
        completed: any[];
        invalid: any[];
    }> {
        const fields = `id name createdAt direction callStatus agentName
            callerNumber { primaryPhoneNumber }
            startedAt endedAt durationSec disposition leadId
            callbackstatus callsourcenumber missedcallcount callbackattemptedat`;

        const buildQuery = (status: string) => `{ calls(first: 50, filter: {
            agentName: { eq: "${agentName}" },
            callStatus: { eq: MISSED },
            callbackstatus: { eq: ${status} }
        }, orderBy: [{ startedAt: AscNullsLast }]) { edges { node { ${fields} } } } }`;

        try {
            const [pending, attempted, completed, invalid, wrongNumber] = await Promise.all([
                this.platform.queryWithAuth<any>(buildQuery('PENDING_CALLBACK'), undefined, authHeader),
                this.platform.queryWithAuth<any>(buildQuery('CALLBACK_ATTEMPTED'), undefined, authHeader),
                this.platform.queryWithAuth<any>(buildQuery('CALLBACK_COMPLETED'), undefined, authHeader),
                this.platform.queryWithAuth<any>(buildQuery('INVALID'), undefined, authHeader),
                this.platform.queryWithAuth<any>(buildQuery('WRONG_NUMBER'), undefined, authHeader),
            ]);

            const extract = (r: any) => r?.calls?.edges?.map((e: any) => e.node) ?? [];

            return {
                pending: extract(pending),
                attempted: extract(attempted),
                completed: [...extract(completed), ...extract(wrongNumber)],
                invalid: extract(invalid),
            };
        } catch (err) {
            this.logger.warn(`Failed to fetch missed queue: ${err}`);
            return { pending: [], attempted: [], completed: [], invalid: [] };
        }
    }
}