/**
 * Caller Resolution Service — unit tests
 *
 * QA coverage: TC-IB-05 (lead creation from enquiry),
 * TC-IB-06 (new patient registration), TC-IB-07/08 (AI context)
 *
 * Tests the phone→lead+patient resolution logic:
 *   - Existing patient + existing lead → returns both, links if needed
 *   - Existing lead, no patient → creates patient, links
 *   - Existing patient, no lead → creates lead, links
 *   - New caller (neither exists) → creates both
 *   - Phone normalization (strips +91, non-digits)
 *   - Cache hit/miss behavior
 */
import { Test } from '@nestjs/testing';
import { CallerResolutionService, ResolvedCaller } from './caller-resolution.service';
import { PlatformGraphqlService } from '../platform/platform-graphql.service';
import { SessionService } from '../auth/session.service';

describe('CallerResolutionService', () => {
    let service: CallerResolutionService;
    let platform: jest.Mocked<PlatformGraphqlService>;
    let cache: jest.Mocked<SessionService>;

    const AUTH = 'Bearer test-token';

    const existingLead = {
        id: 'lead-001',
        contactName: { firstName: 'Priya', lastName: 'Sharma' },
        contactPhone: { primaryPhoneNumber: '+919949879837' },
        patientId: 'patient-001',
    };

    const existingPatient = {
        id: 'patient-001',
        fullName: { firstName: 'Priya', lastName: 'Sharma' },
        phones: { primaryPhoneNumber: '+919949879837' },
    };

    beforeEach(async () => {
        const module = await Test.createTestingModule({
            providers: [
                CallerResolutionService,
                {
                    provide: PlatformGraphqlService,
                    useValue: {
                        queryWithAuth: jest.fn(),
                    },
                },
                {
                    provide: SessionService,
                    useValue: {
                        getCache: jest.fn().mockResolvedValue(null), // no cache by default
                        setCache: jest.fn().mockResolvedValue(undefined),
                    },
                },
            ],
        }).compile();

        service = module.get(CallerResolutionService);
        platform = module.get(PlatformGraphqlService);
        cache = module.get(SessionService);
    });

    // ── TC-IB-05: Existing lead + existing patient ───────────────

    it('TC-IB-05: should return existing lead+patient when both found by phone', async () => {
        platform.queryWithAuth
            // leads query
            .mockResolvedValueOnce({ leads: { edges: [{ node: existingLead }] } })
            // patients query
            .mockResolvedValueOnce({ patients: { edges: [{ node: existingPatient }] } });

        const result = await service.resolve('9949879837', AUTH);

        expect(result.leadId).toBe('lead-001');
        expect(result.patientId).toBe('patient-001');
        expect(result.isNew).toBe(false);
        expect(result.firstName).toBe('Priya');
    });

    // ── TC-IB-06: New caller → creates both lead + patient ──────

    it('TC-IB-06: should create both lead+patient for unknown caller', async () => {
        platform.queryWithAuth
            // leads query → empty
            .mockResolvedValueOnce({ leads: { edges: [] } })
            // patients query → empty
            .mockResolvedValueOnce({ patients: { edges: [] } })
            // createPatient
            .mockResolvedValueOnce({ createPatient: { id: 'new-patient-001' } })
            // createLead
            .mockResolvedValueOnce({ createLead: { id: 'new-lead-001' } });

        const result = await service.resolve('6309248884', AUTH);

        expect(result.leadId).toBe('new-lead-001');
        expect(result.patientId).toBe('new-patient-001');
        expect(result.isNew).toBe(true);
    });

    // ── Lead exists, no patient → creates patient ────────────────

    it('should create patient when lead exists without patient match', async () => {
        const leadNoPatient = { ...existingLead, patientId: null };

        platform.queryWithAuth
            .mockResolvedValueOnce({ leads: { edges: [{ node: leadNoPatient }] } })
            .mockResolvedValueOnce({ patients: { edges: [] } })
            // createPatient
            .mockResolvedValueOnce({ createPatient: { id: 'new-patient-002' } })
            // linkLeadToPatient (updateLead)
            .mockResolvedValueOnce({ updateLead: { id: 'lead-001' } });

        const result = await service.resolve('9949879837', AUTH);

        expect(result.patientId).toBe('new-patient-002');
        expect(result.leadId).toBe('lead-001');
        expect(result.isNew).toBe(false);
    });

    // ── Patient exists, no lead → creates lead ───────────────────

    it('should create lead when patient exists without lead match', async () => {
        platform.queryWithAuth
            .mockResolvedValueOnce({ leads: { edges: [] } })
            .mockResolvedValueOnce({ patients: { edges: [{ node: existingPatient }] } })
            // createLead
            .mockResolvedValueOnce({ createLead: { id: 'new-lead-002' } });

        const result = await service.resolve('9949879837', AUTH);

        expect(result.leadId).toBe('new-lead-002');
        expect(result.patientId).toBe('patient-001');
        expect(result.isNew).toBe(false);
    });

    // ── Phone normalization ──────────────────────────────────────

    it('should normalize phone: strip +91 prefix and non-digits', async () => {
        platform.queryWithAuth
            .mockResolvedValueOnce({ leads: { edges: [] } })
            .mockResolvedValueOnce({ patients: { edges: [] } })
            .mockResolvedValueOnce({ createPatient: { id: 'p' } })
            .mockResolvedValueOnce({ createLead: { id: 'l' } });

        const result = await service.resolve('+91-994-987-9837', AUTH);

        expect(result.phone).toBe('9949879837');
    });

    it('should reject invalid short phone numbers', async () => {
        await expect(service.resolve('12345', AUTH)).rejects.toThrow('Invalid phone');
    });

    // ── Cache hit ────────────────────────────────────────────────

    it('should return cached result without hitting platform', async () => {
        const cached: ResolvedCaller = {
            leadId: 'cached-lead',
            patientId: 'cached-patient',
            firstName: 'Cache',
            lastName: 'Hit',
            phone: '9949879837',
            isNew: false,
        };
        cache.getCache.mockResolvedValueOnce(JSON.stringify(cached));

        const result = await service.resolve('9949879837', AUTH);

        expect(result).toEqual(cached);
        expect(platform.queryWithAuth).not.toHaveBeenCalled();
    });

    // ── Cache write ──────────────────────────────────────────────

    it('should cache result after successful resolve', async () => {
        platform.queryWithAuth
            .mockResolvedValueOnce({ leads: { edges: [{ node: existingLead }] } })
            .mockResolvedValueOnce({ patients: { edges: [{ node: existingPatient }] } });

        await service.resolve('9949879837', AUTH);

        expect(cache.setCache).toHaveBeenCalledWith(
            'caller:9949879837',
            expect.any(String),
            3600,
        );
    });

    // ── Links unlinked lead to patient ───────────────────────────

    it('should link lead to patient when both exist but are unlinked', async () => {
        const unlinkedLead = { ...existingLead, patientId: null };

        platform.queryWithAuth
            .mockResolvedValueOnce({ leads: { edges: [{ node: unlinkedLead }] } })
            .mockResolvedValueOnce({ patients: { edges: [{ node: existingPatient }] } })
            // updateLead to link
            .mockResolvedValueOnce({ updateLead: { id: 'lead-001' } });

        const result = await service.resolve('9949879837', AUTH);

        expect(result.leadId).toBe('lead-001');
        expect(result.patientId).toBe('patient-001');

        // Verify the link mutation was called
        const linkCall = platform.queryWithAuth.mock.calls.find(
            c => typeof c[0] === 'string' && c[0].includes('updateLead'),
        );
        expect(linkCall).toBeDefined();
    });
});