import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import axios from 'axios';
import type {
  LeadNode,
  LeadActivityNode,
  CreateCallInput,
  CreateLeadActivityInput,
  UpdateLeadInput,
} from './platform.types';

@Injectable()
export class PlatformGraphqlService {
  private readonly graphqlUrl: string;
  private readonly apiKey: string;

  constructor(private config: ConfigService) {
    this.graphqlUrl = config.get<string>('platform.graphqlUrl')!;
    this.apiKey = config.get<string>('platform.apiKey')!;
  }

  // Server-to-server query using API key
  async query<T>(query: string, variables?: Record<string, any>): Promise<T> {
    return this.queryWithAuth<T>(query, variables, `Bearer ${this.apiKey}`);
  }

  // Query using a passed-through auth header (user JWT)
  async queryWithAuth<T>(
    query: string,
    variables: Record<string, any> | undefined,
    authHeader: string,
  ): Promise<T> {
    const response = await axios.post(
      this.graphqlUrl,
      { query, variables },
      {
        headers: {
          'Content-Type': 'application/json',
          Authorization: authHeader,
        },
      },
    );

    if (response.data.errors) {
      throw new Error(`GraphQL error: ${JSON.stringify(response.data.errors)}`);
    }

    return response.data.data;
  }

  async findLeadByPhone(phone: string): Promise<LeadNode | null> {
    // Note: The exact filter syntax for PHONES fields depends on the platform
    // This queries leads and filters client-side by phone number
    const data = await this.query<{ leads: { edges: { node: LeadNode }[] } }>(
      `query FindLeads($first: Int) {
                leads(first: $first, orderBy: { createdAt: DescNullsLast }) {
                    edges {
                        node {
                            id createdAt
                            contactName { firstName lastName }
                            contactPhone { number callingCode }
                            contactEmail { address }
                            leadSource leadStatus interestedService
                            assignedAgent campaignId adId
                            contactAttempts spamScore isSpam
                            aiSummary aiSuggestedAction
                        }
                    }
                }
            }`,
      { first: 100 },
    );

    // Client-side phone matching (strip non-digits for comparison)
    const normalizedPhone = phone.replace(/\D/g, '');
    return (
      data.leads.edges.find((edge) => {
        const leadPhones = edge.node.contactPhone ?? [];
        return leadPhones.some(
          (p) =>
            p.number.replace(/\D/g, '').endsWith(normalizedPhone) ||
            normalizedPhone.endsWith(p.number.replace(/\D/g, '')),
        );
      })?.node ?? null
    );
  }

  async findLeadById(id: string): Promise<LeadNode | null> {
    const data = await this.query<{ lead: LeadNode }>(
      `query FindLead($id: ID!) {
                lead(id: $id) {
                    id createdAt
                    contactName { firstName lastName }
                    contactPhone { number callingCode }
                    contactEmail { address }
                    leadSource leadStatus interestedService
                    assignedAgent campaignId adId
                    contactAttempts spamScore isSpam
                    aiSummary aiSuggestedAction
                }
            }`,
      { id },
    );
    return data.lead;
  }

  async updateLead(id: string, input: UpdateLeadInput): Promise<LeadNode> {
    const data = await this.query<{ updateLead: LeadNode }>(
      `mutation UpdateLead($id: ID!, $data: LeadUpdateInput!) {
                updateLead(id: $id, data: $data) {
                    id leadStatus aiSummary aiSuggestedAction
                }
            }`,
      { id, data: input },
    );
    return data.updateLead;
  }

  async createCall(input: CreateCallInput): Promise<{ id: string }> {
    const data = await this.query<{ createCall: { id: string } }>(
      `mutation CreateCall($data: CallCreateInput!) {
                createCall(data: $data) { id }
            }`,
      { data: input },
    );
    return data.createCall;
  }

  async createLeadActivity(
    input: CreateLeadActivityInput,
  ): Promise<{ id: string }> {
    const data = await this.query<{ createLeadActivity: { id: string } }>(
      `mutation CreateLeadActivity($data: LeadActivityCreateInput!) {
                createLeadActivity(data: $data) { id }
            }`,
      { data: input },
    );
    return data.createLeadActivity;
  }

  // --- Token passthrough versions (for user-driven requests) ---

  async findLeadByPhoneWithToken(
    phone: string,
    authHeader: string,
  ): Promise<LeadNode | null> {
    const normalizedPhone = phone.replace(/\D/g, '');
    const last10 = normalizedPhone.slice(-10);

    const data = await this.queryWithAuth<{
      leads: { edges: { node: LeadNode }[] };
    }>(
      `query FindLeads($first: Int) {
                leads(first: $first, orderBy: [{ createdAt: DescNullsLast }]) {
                    edges {
                        node {
                            id createdAt
                            contactName { firstName lastName }
                            contactPhone { number callingCode }
                            contactEmail { address }
                            leadSource leadStatus interestedService
                            assignedAgent campaignId adId
                            contactAttempts spamScore isSpam
                            aiSummary aiSuggestedAction
                        }
                    }
                }
            }`,
      { first: 200 },
      authHeader,
    );

    // Client-side phone matching
    return (
      data.leads.edges.find((edge) => {
        const phones = edge.node.contactPhone ?? [];
        if (Array.isArray(phones)) {
          return phones.some((p: any) => {
            const num = (p.number ?? p.primaryPhoneNumber ?? '').replace(
              /\D/g,
              '',
            );
            return num.endsWith(last10) || last10.endsWith(num);
          });
        }
        // Handle single phone object
        const num = (
          (phones as any).primaryPhoneNumber ??
          (phones as any).number ??
          ''
        ).replace(/\D/g, '');
        return num.endsWith(last10) || last10.endsWith(num);
      })?.node ?? null
    );
  }

  async getLeadActivitiesWithToken(
    leadId: string,
    authHeader: string,
    limit = 5,
  ): Promise<LeadActivityNode[]> {
    const data = await this.queryWithAuth<{
      leadActivities: { edges: { node: LeadActivityNode }[] };
    }>(
      `query GetLeadActivities($filter: LeadActivityFilterInput, $first: Int) {
                leadActivities(filter: $filter, first: $first, orderBy: [{ occurredAt: DescNullsLast }]) {
                    edges {
                        node {
                            id activityType summary occurredAt performedBy channel
                        }
                    }
                }
            }`,
      { filter: { leadId: { eq: leadId } }, first: limit },
      authHeader,
    );
    return data.leadActivities.edges.map((e) => e.node);
  }

  async updateLeadWithToken(
    id: string,
    input: UpdateLeadInput,
    authHeader: string,
  ): Promise<LeadNode> {
    // Response fragment deliberately excludes `leadStatus` — the staging
    // platform schema has this field renamed to `status`. Selecting the
    // old name rejects the whole mutation. Callers don't use the
    // returned fragment today, so returning just the id + AI fields
    // keeps this working across both schema shapes without a wider
    // rename hotfix.
    const data = await this.queryWithAuth<{ updateLead: LeadNode }>(
      `mutation UpdateLead($id: ID!, $data: LeadUpdateInput!) {
                updateLead(id: $id, data: $data) {
                    id aiSummary aiSuggestedAction
                }
            }`,
      { id, data: input },
      authHeader,
    );
    return data.updateLead;
  }

  // Fetch a single lead by id with the caller's JWT. Used by the
  // lead-enrich flow when the agent explicitly renames a caller from
  // the appointment/enquiry form and we need to regenerate the lead's
  // AI summary against fresh identity.
  //
  // The selected fields deliberately use the staging-aligned names
  // (`status`, `source`, `lastContacted`) rather than the older
  // `leadStatus`/`leadSource`/`lastContactedAt` names — otherwise the
  // query would be rejected on staging.
  async findLeadByIdWithToken(
    id: string,
    authHeader: string,
  ): Promise<any | null> {
    try {
      const data = await this.queryWithAuth<{ lead: any }>(
        `query FindLead($id: UUID!) {
                    lead(filter: { id: { eq: $id } }) {
                        id
                        createdAt
                        contactName { firstName lastName }
                        contactPhone { primaryPhoneNumber primaryPhoneCallingCode }
                        source
                        status
                        interestedService
                        contactAttempts
                        lastContacted
                        aiSummary
                        aiSuggestedAction
                    }
                }`,
        { id },
        authHeader,
      );
      return data.lead ?? null;
    } catch {
      // Fall back to edge-style query in case the singular field
      // doesn't exist on this platform version.
      const data = await this.queryWithAuth<{
        leads: { edges: { node: any }[] };
      }>(
        `query FindLead($id: UUID!) {
                    leads(filter: { id: { eq: $id } }, first: 1) {
                        edges {
                            node {
                                id
                                createdAt
                                contactName { firstName lastName }
                                contactPhone { primaryPhoneNumber primaryPhoneCallingCode }
                                source
                                status
                                interestedService
                                contactAttempts
                                lastContacted
                                aiSummary
                                aiSuggestedAction
                            }
                        }
                    }
                }`,
        { id },
        authHeader,
      );
      return data.leads.edges[0]?.node ?? null;
    }
  }

  async getPatientWithToken(
    patientId: string,
    authHeader: string,
  ): Promise<any | null> {
    try {
      const data = await this.queryWithAuth<{ patient: any }>(
        `query GetPatient($id: UUID!) {
                    patient(filter: { id: { eq: $id } }) {
                        id
                        fullName { firstName lastName }
                        dateOfBirth
                        patientType
                    }
                }`,
        { id: patientId },
        authHeader,
      );
      return data.patient ?? null;
    } catch {
      return null;
    }
  }

  async getUpcomingAppointmentsWithToken(
    patientId: string,
    authHeader: string,
    limit = 3,
  ): Promise<any[]> {
    try {
      const data = await this.queryWithAuth<{
        appointments: { edges: { node: any }[] };
      }>(
        `query GetAppointments($filter: AppointmentFilterInput, $first: Int) {
                    appointments(filter: $filter, first: $first, orderBy: [{ scheduledAt: AscNullsLast }]) {
                        edges {
                            node {
                                id
                                scheduledAt
                                appointmentType
                                doctorName
                                status
                            }
                        }
                    }
                }`,
        {
          filter: {
            patientId: { eq: patientId },
            scheduledAt: { gte: new Date().toISOString() },
          },
          first: limit,
        },
        authHeader,
      );
      return data.appointments.edges.map((e) => e.node);
    } catch {
      return [];
    }
  }

  // --- Server-to-server versions (for webhooks, background jobs) ---

  async getLeadActivities(
    leadId: string,
    limit = 3,
  ): Promise<LeadActivityNode[]> {
    const data = await this.query<{
      leadActivities: { edges: { node: LeadActivityNode }[] };
    }>(
      `query GetLeadActivities($filter: LeadActivityFilterInput, $first: Int) {
                leadActivities(filter: $filter, first: $first, orderBy: { occurredAt: DescNullsLast }) {
                    edges {
                        node {
                            id activityType summary occurredAt performedBy channel
                        }
                    }
                }
            }`,
      { filter: { leadId: { eq: leadId } }, first: limit },
    );
    return data.leadActivities.edges.map((e) => e.node);
  }
}