import { Injectable, HttpException, HttpStatus } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository, DataSource } from 'typeorm';
import { RoadSpeedProfile } from './road-speed-profile.entity';
import axios from 'axios';
import { RoadSegmentStat } from './road-stat.entity';
import { TrafficGridService } from './traffic-grid.service';
import { FuelPricingService } from './fuel-pricing.service';
import { GeocodingService } from '../geocoding/geocoding.service';
import { RedisService } from '../common/redis.service';

@Injectable()
export class MapsService {
  private readonly graphHopperUrl: string;

  constructor(
    private configService: ConfigService,
    @InjectRepository(RoadSegmentStat)
    private roadStatRepo: Repository<RoadSegmentStat>,
    private trafficGrid: TrafficGridService,
    private fuelPricingService: FuelPricingService,
    private geocodingService: GeocodingService,
    private dataSource: DataSource,
    private redisService: RedisService,
  ) {
    this.graphHopperUrl = this.configService.get('GRAPH_HOPPER_URL', 'http://routing:8080');
  }

  async requestRoutingSync() {
    await this.redisService.set('routing_sync_requested', '1');
    return { success: true, message: 'Routing sync requested and scheduled for the next minute.' };
  }


  async getRoute(waypoints: [number, number][], profile: string = 'car', steps: boolean = false, locale: string = 'en', alternatives: boolean = false) {
    if (waypoints.length < 2) {
      throw new HttpException('At least two waypoints are required', HttpStatus.BAD_REQUEST);
    }

    try {
      // GraphHopper expects [lng, lat] order
      const ghPoints = waypoints.map(wp => [wp[1], wp[0]]);

      let startName = 'Unknown Location';
      let endName = 'Unknown Location';
      try {
        const startWp = waypoints[0];
        const endWp = waypoints[waypoints.length - 1];
        const [startRes, endRes] = await Promise.all([
          this.geocodingService.reverseGeocode(startWp[0], startWp[1]),
          this.geocodingService.reverseGeocode(endWp[0], endWp[1])
        ]);

        const formatName = (r: any) => {
          const parts = [r.name_ar || r.name, r.neighbourhood, r.district, r.governorate].filter(Boolean);
          // Deduplicate items continuously (e.g. if name is similar to neighborhood)
          const uniqueParts = [...new Set(parts)];
          return uniqueParts.length > 0 ? uniqueParts.join('، ') : 'Unknown Location';
        };

        if (startRes && startRes.length > 0) startName = formatName(startRes[0]);
        if (endRes && endRes.length > 0) endName = formatName(endRes[0]);
      } catch (e) {
        console.warn('Geocoding internal error during routing:', e);
      }

      const payload: any = {
        points: ghPoints,
        profile: profile,
        locale: locale === 'en' ? 'ar' : locale, // Default to Arabic if not specified or fallback
        calc_points: true,
        points_encoded: true,
        instructions: steps || true, // Always request instructions to extract route name
      };

      // ── Closure-Aware Routing ─────────────────────────────────────────────
      // Roads the telemetry analyzer flagged as closed are handed to GraphHopper
      // as custom-model "areas" so the router avoids them. Two bugs from the first
      // version are fixed here:
      //   1. Areas MUST be polygons. road_segment_stats.geometry is a LineString,
      //      so we buffer it (~15 m) into a polygon in SQL before sending.
      //   2. Each rule must reference its area by the exact id the area declares
      //      (in_<id>). The old code called indexOf() on a different array and
      //      always produced `in_custom_area-1` (a non-existent area) — GraphHopper
      //      then rejected the request with 400, taking down ALL routing.
      // closureCount lets the send step below retry without closures if GH still
      // refuses the custom model, so a bad closure can never break routing.
      let closureCount = 0;
      try {
        const closedSegments = await this.dataSource.query(`
          SELECT ST_AsGeoJSON(
                   ST_Transform(ST_Buffer(ST_Transform(geometry::geometry, 3857), 15), 4326), 6
                 ) AS geojson
          FROM road_segment_stats
          WHERE "isClosed" = true AND geometry IS NOT NULL
          LIMIT 50
        `);

        const features = closedSegments
          .map((s: any, i: number) => {
            try {
              return { type: 'Feature', id: `closed_${i}`, geometry: JSON.parse(s.geojson), properties: {} };
            } catch { return null; }
          })
          .filter(Boolean);

        if (features.length > 0) {
          payload['custom_model'] = {
            priority: features.map((f: any) => ({ if: `in_${f.id}`, multiply_by: '0' })),
            areas: { type: 'FeatureCollection', features },
          };
          payload['ch.disable'] = true; // request-time custom models require CH disabled
          closureCount = features.length;
          console.log(`🚧 Routing: avoiding ${closureCount} closed segment(s).`);
        }
      } catch (closureError) {
        // Non-fatal — routing continues normally without closure avoidance.
        console.warn('⚠️  Could not load road closures for routing:', closureError.message);
      }
      // ─────────────────────────────────────────────────────────────────────


      // GraphHopper ONLY supports alternative routes if there are exactly 2 points (Start and End)
      if (alternatives && waypoints.length === 2) {
        payload.algorithm = 'alternative_route';
        payload['ch.disable'] = true; // Required for alternative routes
        payload['alternative_route.max_paths'] = 3; // Return main route + up to 2 distinct alternatives
        payload['alternative_route.max_weight_factor'] = 1.8;
        payload['alternative_route.max_share_factor'] = 0.75;
      }

      console.log(`Routing Request: ${waypoints.length} points via ${profile} on ${this.graphHopperUrl} | Steps: ${steps} | Locale: ${locale}`);
      let response: any;
      try {
        response = await axios.post(`${this.graphHopperUrl}/route`, payload, { timeout: 10000 });
      } catch (routeErr) {
        // Safety net: if the closure-aware custom model was rejected, retry once
        // WITHOUT it so an unsupported/bad closure can never take down all routing.
        if (closureCount > 0 && payload['custom_model']) {
          const detail = routeErr.response ? JSON.stringify(routeErr.response.data) : routeErr.message;
          console.warn(`⚠️  Closure-aware routing failed (${detail}). Retrying without closures...`);
          delete payload['custom_model'];
          // Keep ch.disable only if the alternative-route block below still needs it.
          if (!(alternatives && waypoints.length === 2)) delete payload['ch.disable'];
          response = await axios.post(`${this.graphHopperUrl}/route`, payload, { timeout: 10000 });
        } else {
          throw routeErr;
        }
      }

      console.log('Routing SUCCESS');
      const paths = response.data.paths;
      if (!paths || paths.length === 0) throw new HttpException('No route found', HttpStatus.NOT_FOUND);

      const route = paths[0];

      // --- PHASE 3: TRAFFIC-AWARE ADJUSTMENT (V3 Optimized) ---
      const now = new Date();
      const hr = now.getHours();
      const dow = now.getDay();

      const coords = this.decodePolyline(route.points);
      const trafficFactor = this.trafficGrid.getTrafficFactor(coords, hr, dow);

      const baseDuration = route.time / 1000;
      const trafficAwareDuration = baseDuration * trafficFactor;

      // 1. Identify the primary route's major artery/street
      const mainInstructions = paths[0]?.instructions || [];
      const mainStreetName = this.getRouteName(mainInstructions);

      // Process all paths to add metadata (Real Street Names, Tags, Elevation & Slope Warnings, Eco/Fuel metrics)
      const processedPaths = paths.map((p: any, index: number) => {
        const pCoords = this.decodePolyline(p.points);
        const pTrafficFactor = this.trafficGrid.getTrafficFactor(pCoords, hr, dow);
        const pBaseDuration = p.time / 1000;
        const pDuration = Math.round(pBaseDuration * pTrafficFactor);
        
        // For alternative routes, find the distinctive street that differentiates it from the main route
        let routeStreet = index === 0 
          ? mainStreetName 
          : this.getRouteName(p.instructions, mainStreetName || undefined);

        // Fallback to any valid street name if differential lookup didn't find one
        if (!routeStreet) {
          routeStreet = this.getRouteName(p.instructions);
        }

        // Format route name with Arabic prefix
        let finalRouteName = '';
        if (routeStreet) {
          const cleanStreet = routeStreet.replace(/^عبر\s+/, '').trim();
          finalRouteName = `عبر ${cleanStreet}`;
        } else {
          finalRouteName = index === 0 ? 'المسار المباشر الأسرع' : 'مسار بديل عبر الطرق الموازية';
        }
        
        // Analyze slopes and enrich instructions
        const { enrichedInstructions, slopeSummary } = this.enrichInstructionsWithSlopeAnalysis(p.instructions, pCoords);

        // Calculate Energy, Fuel Consumption & Eco Cost (combining Distance + Ascent/Descent Physics + Traffic/Time Delays)
        const ecoMetrics = this.calculateEcoAndFuelMetrics(
          p.distance,
          slopeSummary.totalAscentMeters,
          slopeSummary.totalDescentMeters,
          slopeSummary.maxInclinePercent,
          slopeSummary.maxDeclinePercent,
          pBaseDuration,
          pDuration,
          pTrafficFactor,
          profile
        );

        // Tags assignment
        const tags: string[] = [];
        if (index === 0) tags.push('FASTEST');
        if (paths.length > 1) {
          const isShortest = paths.every((other: any) => p.distance <= other.distance);
          if (isShortest) tags.push('SHORTEST');
          if (index > 0 && !isShortest) tags.push('ALTERNATIVE');
        }
        if (ecoMetrics.ecoScore >= 85) {
          tags.push('ECO_FRIENDLY');
        }

        return {
          routeName: finalRouteName,
          tags,
          distance: p.distance,
          duration: pDuration,
          points: p.points,
          bbox: p.bbox,
          instructions: steps ? enrichedInstructions : undefined,
          elevationSummary: slopeSummary,
          ecoMetrics
        };
      });

      const mainRoute = processedPaths[0];
      const altRoutes = processedPaths.slice(1);

      return {
        routeName: mainRoute.routeName,
        tags: mainRoute.tags,
        distance: mainRoute.distance,
        duration: mainRoute.duration,
        trafficFactor: Math.round(trafficFactor * 100) / 100,
        startName,
        endName,
        points: mainRoute.points,
        bbox: mainRoute.bbox,
        instructions: mainRoute.instructions,
        elevationSummary: mainRoute.elevationSummary,
        ecoMetrics: mainRoute.ecoMetrics,
        alternatives: altRoutes
      };
    } catch (error) {
      if (error instanceof HttpException) {
        throw error;
      }

      const ghData = error.response?.data;
      const rawMsg = ghData?.message || error.message || '';

      // 1. Point Not Found (Outside coverage area or in water/remote off-road)
      if (rawMsg.includes('Cannot find point') || rawMsg.includes('PointNotFoundException')) {
        const pointMatch = rawMsg.match(/Cannot find point\s+(\d+):\s*([0-9.,]+)/i);
        const pointIndex = pointMatch ? (Number(pointMatch[1]) + 1) : '';
        const pointCoords = pointMatch ? `[${pointMatch[2]}]` : '';
        
        throw new HttpException(
          `تعذر العثور على مسار: النقطة ${pointIndex ? `رقم ${pointIndex}` : ''} ${pointCoords} تقع خارج نطاق خريطة الأردن المعتمدة أو في منطقة حدودية/وعرة بعيدة عن شبكة الطرق المعبدة.`,
          HttpStatus.UNPROCESSABLE_ENTITY
        );
      }

      // 2. No connection between locations (e.g. islands, separated networks)
      if (rawMsg.includes('Connection between locations not found')) {
        throw new HttpException(
          'لا يوجد مسار أو شبكة طرق معبدة متصلة تربط بين نقطة الانطلاق والوجهة المحددة.',
          HttpStatus.UNPROCESSABLE_ENTITY
        );
      }

      const msg = error.response ? `GH Error: ${JSON.stringify(error.response.data)}` : `DNS/Connection Error: ${error.message}`;
      console.error('CRITICAL ROUTING FAILURE:', msg);
      throw new HttpException(`Routing Failure: ${msg}`, HttpStatus.BAD_GATEWAY);
    }
  }

  /**
   * Enriches turn-by-turn routing instructions with steep slope / incline warnings
   */
  private enrichInstructionsWithSlopeAnalysis(instructions: any[], coords: [number, number][]) {
    if (!instructions || !coords || coords.length < 2) {
      return {
        enrichedInstructions: instructions,
        slopeSummary: { totalAscentMeters: 0, totalDescentMeters: 0, maxInclinePercent: 0, maxDeclinePercent: 0, steepWarningsCount: 0, steepWarnings: [] }
      };
    }

    let totalAscent = 0;
    let totalDescent = 0;
    let maxInclinePercent = 0;
    let maxDeclinePercent = 0;
    const steepWarnings: any[] = [];

    const enrichedInstructions = instructions.map((inst: any) => {
      const interval = inst.interval || [0, 0];
      const startIdx = Math.min(interval[0], coords.length - 1);
      const endIdx = Math.min(interval[1], coords.length - 1);

      // 1. Localize text into 100% fluent Arabic
      const localizedBaseText = this.localizeInstructionToArabic(inst.text);

      if (startIdx < endIdx) {
        let stepAscent = 0;
        let stepDescent = 0;

        for (let i = startIdx; i < endIdx; i++) {
          const c1 = coords[i];
          const c2 = coords[i + 1];
          const e1 = this.estimateElevation(c1[1], c1[0]);
          const e2 = this.estimateElevation(c2[1], c2[0]);
          const dDiff = e2 - e1;

          if (dDiff > 0) stepAscent += dDiff;
          else stepDescent += Math.abs(dDiff);
        }

        totalAscent += stepAscent;
        totalDescent += stepDescent;

        const dist = Math.max(40, inst.distance || 1);
        const netStepDiff = stepAscent - stepDescent;

        // Realistic slope calculation calibrated for highway/urban gradients
        const calculatedSlope = Math.round((netStepDiff / dist) * 100);
        const slopePercent = Math.max(-14, Math.min(14, calculatedSlope));

        if (slopePercent > maxInclinePercent) maxInclinePercent = slopePercent;
        if (slopePercent < maxDeclinePercent) maxDeclinePercent = slopePercent;

        // Warning only for truly steep inclines/declines (10% or higher)
        let warning_ar: string | null = null;
        if (slopePercent >= 10) {
          warning_ar = `⚠️ تنبيه: صعود حاد (+${slopePercent}%)`;
          steepWarnings.push({ text: localizedBaseText, slopePercent, type: 'incline', street: inst.street_name });
        } else if (slopePercent <= -10) {
          warning_ar = `⚠️ تنبيه: منحدر شديد (${slopePercent}%) - خفف السرعة`;
          steepWarnings.push({ text: localizedBaseText, slopePercent, type: 'decline', street: inst.street_name });
        }

        return {
          ...inst,
          slopePercent,
          elevationChangeMeters: Math.round(netStepDiff),
          slopeWarning: warning_ar || undefined,
          text: warning_ar ? `${localizedBaseText} (${warning_ar})` : localizedBaseText
        };
      }

      return {
        ...inst,
        text: localizedBaseText
      };
    });

    return {
      enrichedInstructions,
      slopeSummary: {
        totalAscentMeters: Math.round(totalAscent),
        totalDescentMeters: Math.round(totalDescent),
        maxInclinePercent: Math.round(maxInclinePercent),
        maxDeclinePercent: Math.round(maxDeclinePercent),
        steepWarningsCount: steepWarnings.length,
        steepWarnings
      }
    };
  }

  /**
   * Calculates comprehensive fuel, energy, and eco-cost metrics combining distance, elevation topography, and traffic delays.
   */
  private calculateEcoAndFuelMetrics(
    distanceMeters: number,
    totalAscentMeters: number,
    totalDescentMeters: number,
    maxInclinePercent: number,
    maxDeclinePercent: number,
    baseDurationSeconds: number,
    actualDurationSeconds: number,
    trafficFactor: number,
    profile: string = 'car'
  ) {
    const distKm = distanceMeters / 1000;
    
    // 1. Base Cruising Fuel: ~0.070 L/km for standard passenger car
    const baseFuelRateLPerKm = profile === 'truck' ? 0.28 : (profile === 'bike' || profile === 'foot') ? 0.0 : 0.070;
    const baseGasolineLiters = distKm * baseFuelRateLPerKm;
    
    // 2. Gravity Work Penalty on Ascent: +0.16 Liters per 100m vertical ascent
    const ascentFuelPenaltyLiters = (totalAscentMeters / 100) * (profile === 'truck' ? 0.45 : 0.16);
    
    // 3. Descent Savings (Gravity Assist / Engine Braking): -0.04 Liters per 100m descent
    const descentFuelSavingLiters = (totalDescentMeters / 100) * (profile === 'truck' ? 0.10 : 0.04);
    
    // 4. Traffic & Congestion Delay Fuel (Idling + Stop-and-Go Re-acceleration):
    const delayHours = Math.max(0, actualDurationSeconds - baseDurationSeconds) / 3600;
    const congestionFactorBonus = trafficFactor > 1.15 ? (trafficFactor - 1.0) * 0.4 : 0.0;
    const trafficFuelLiters = (delayHours * 1.1) + (baseGasolineLiters * congestionFactorBonus);
    
    // Net Gasoline Consumption
    const netGasolineLiters = Math.max(0.05, baseGasolineLiters + ascentFuelPenaltyLiters - descentFuelSavingLiters + trafficFuelLiters);
    
    // Pricing in Jordan (Live monthly pricing updated via FuelPricingService & Gemini AI)
    const livePrices = this.fuelPricingService.getPrices();
    const fuelPricePerLiter = profile === 'truck' ? livePrices.diesel : livePrices.gasoline90;
    const estimatedCostJOD = netGasolineLiters * fuelPricePerLiter;
    
    // 5. EV Energy Model (Electric Vehicles):
    const baseEvKWh = distKm * 0.15;
    const ascentEvKWh = (totalAscentMeters / 100) * 0.38;
    const regenEvKWh = (totalDescentMeters / 100) * 0.26;
    const trafficEvKWh = delayHours * 1.5; // HVAC & auxiliary electronics in standstill
    const netEvKWh = Math.max(0.1, baseEvKWh + ascentEvKWh - regenEvKWh + trafficEvKWh);
    const estimatedEvCostJOD = netEvKWh * (livePrices.evKWh || 0.120);
    
    // Carbon Footprint: 2,310g CO2 per liter of gasoline
    const co2Grams = Math.round(netGasolineLiters * 2310);
    
    // 6. Net Elevation Differential (هل المسار صاعد أم هابط؟)
    const isPredominantlyDescent = totalDescentMeters > (totalAscentMeters * 1.3);
    const isPredominantlyAscent = totalAscentMeters > (totalDescentMeters * 1.3);
    
    // 7. Terrain Difficulty & Mechanical Guidance
    let terrainDifficultyArabic = 'طريق مستوٍ مريح';
    let mechanicalAdviceArabic = 'القيادة في نطاق السرعة الطبيعي';

    if (isPredominantlyDescent) {
      if (Math.abs(maxDeclinePercent) >= 8) {
        terrainDifficultyArabic = 'منحدر جبلي هابط (نزول حاد)';
        mechanicalAdviceArabic = '⚠️ استخدام الغيار المنخفض (Engine Braking) لتخفيف العبء على الفرامل وتجنب ارتفاع حرارتها';
      } else {
        terrainDifficultyArabic = 'طريق منحدر خفيف (هبوط سلس)';
        mechanicalAdviceArabic = 'مسير هابط موفر للوقود مع شحن متجدد لبطارية الـ EV';
      }
    } else if (isPredominantlyAscent) {
      if (maxInclinePercent >= 8) {
        terrainDifficultyArabic = 'طريق صاعد جبلي (عقبة صعود حادة)';
        mechanicalAdviceArabic = 'يتطلب عزم محرك إضافي واستخدام الغيارات المناسبة لمنع إجهاد المحرك';
      } else {
        terrainDifficultyArabic = 'طريق صاعد معتدل';
        mechanicalAdviceArabic = 'صعود تدريجي بجهد محرك معتدل';
      }
    } else {
      if (maxInclinePercent >= 8 || Math.abs(maxDeclinePercent) >= 8) {
        terrainDifficultyArabic = 'تضاريس جبلية وعرة (صعود وهبوط متكرر)';
        mechanicalAdviceArabic = 'تدرج مستمر بين عزم الصعود وكبح النزول';
      } else if (maxInclinePercent >= 4 || Math.abs(maxDeclinePercent) >= 4) {
        terrainDifficultyArabic = 'تضاريس متموجة معتدلة';
        mechanicalAdviceArabic = 'قيادة سلسة ومريحة للمركبة';
      }
    }

    // 8. Eco Score & Badge Calculation
    const idealFlatFuel = distKm * baseFuelRateLPerKm;
    const consumptionRatio = idealFlatFuel > 0 ? (netGasolineLiters / idealFlatFuel) : 1.0;
    
    let rawScore = Math.round(100 - (consumptionRatio - 1.0) * 50);
    if (isPredominantlyDescent) rawScore = Math.max(rawScore, 92); // Descent is naturally fuel-efficient
    const ecoScore = Math.max(15, Math.min(100, rawScore));
    
    let ecoBadgeArabic = 'مسار قياسي متوازن';
    if (isPredominantlyDescent && trafficFactor < 1.2) {
      ecoBadgeArabic = 'مسار موفر للوقود بالهبوط 🌿 (شحن للـ EV)';
    } else if (ecoScore >= 85 && trafficFactor < 1.15) {
      ecoBadgeArabic = 'مسار اقتصادي منخفض الاستهلاك 🌿';
    } else if (trafficFactor >= 1.35) {
      ecoBadgeArabic = 'مسار عالي الاستهلاك (بسبب الازدحام والتوقف) ⏳';
    } else if (isPredominantlyAscent && maxInclinePercent >= 8) {
      ecoBadgeArabic = 'مسار عالي الاستهلاك في الصعود ⚠️';
    }

    return {
      estimatedGasolineLiters: Math.round(netGasolineLiters * 100) / 100,
      estimatedCostJOD: Math.round(estimatedCostJOD * 100) / 100,
      estimatedEvKWh: Math.round(netEvKWh * 100) / 100,
      estimatedEvCostJOD: Math.round(estimatedEvCostJOD * 100) / 100,
      energyRecoveredEvKWh: Math.round(regenEvKWh * 100) / 100,
      co2Kg: Math.round((co2Grams / 1000) * 100) / 100,
      trafficDelayMinutes: Math.round(delayHours * 60),
      ecoScore,
      ecoBadge: ecoBadgeArabic,
      terrainDifficulty: terrainDifficultyArabic,
      mechanicalAdvice: mechanicalAdviceArabic,
      pricingBulletin: {
        gasoline90JOD: livePrices.gasoline90,
        dieselJOD: livePrices.diesel,
        effectiveMonth: livePrices.effectiveMonth,
        source: livePrices.source,
      }
    };
  }

  /**
   * Translates any English phrases from routing engines (GraphHopper) into natural, fluent Arabic.
   */
  private localizeInstructionToArabic(rawText: string): string {
    if (!rawText) return '';

    let text = rawText.trim();

    // 1. English Directional & Maneuver Replacements
    const phrases: [RegExp, string][] = [
      // Continuations
      [/^Continue onto\s+/i, 'تابع السير في '],
      [/^Continue on\s+/i, 'تابع السير في '],
      [/^Continue straight\s+/i, 'تابع السير بشكل مستقيم في '],
      [/^Continue straight$/i, 'تابع السير للأمام مباشرة'],
      [/^Continue\s*$/i, 'تابع السير للأمام'],
      
      // Roundabouts
      [/في الدوران\s*،\s*أتخذ مخرج\s+(\d+)\s+من خلال/i, 'عند الدوار، اسلك المخرج $1 عبر'],
      [/في الدوران\s*،\s*اتخذ مخرج\s+(\d+)\s+من خلال/i, 'عند الدوار، اسلك المخرج $1 عبر'],
      [/في الدوران\s*،\s*أتخذ مخرج\s+(\d+)/i, 'عند الدوار، اسلك المخرج $1'],
      [/في الدوران\s*،\s*اتخذ مخرج\s+(\d+)/i, 'عند الدوار، اسلك المخرج $1'],
      [/At roundabout, take exit\s+(\d+)\s+onto/i, 'عند الدوار، اسلك المخرج $1 عبر'],
      [/At roundabout, take exit\s+(\d+)/i, 'عند الدوار، اسلك المخرج $1'],
      [/In roundabout, take exit\s+(\d+)/i, 'عند الدوار، اسلك المخرج $1'],

      // Turns
      [/^Turn sharp right onto\s+/i, 'انعطف يميناً بشكل حاد إلى '],
      [/^Turn slight right onto\s+/i, 'انعطف يميناً بشكل طفيف إلى '],
      [/^Turn right onto\s+/i, 'اتجه يميناً إلى '],
      [/^Turn sharp right/i, 'انعطف يميناً بشكل حاد'],
      [/^Turn slight right/i, 'انعطف يميناً بشكل طفيف'],
      [/^Turn right/i, 'اتجه يميناً'],

      [/^Turn sharp left onto\s+/i, 'انعطف يساراً بشكل حاد إلى '],
      [/^Turn slight left onto\s+/i, 'انعطف يساراً بشكل طفيف إلى '],
      [/^Turn left onto\s+/i, 'اتجه يساراً إلى '],
      [/^Turn sharp left/i, 'انعطف يساراً بشكل حاد'],
      [/^Turn slight left/i, 'انعطف يساراً بشكل طفيف'],
      [/^Turn left/i, 'اتجه يساراً'],

      // Keeps
      [/^Keep right toward\s+/i, 'الزم اليمين باتجاه '],
      [/^Keep right onto\s+/i, 'الزم اليمين في '],
      [/^Keep right/i, 'الزم اليمين'],
      [/^احفظ اليمين toward\s+/i, 'الزم اليمين باتجاه '],
      [/^احفظ اليمين خلال\s+/i, 'الزم اليمين عبر '],
      [/^احفظ اليمين/i, 'الزم اليمين'],

      [/^Keep left toward\s+/i, 'الزم اليسار باتجاه '],
      [/^Keep left onto\s+/i, 'الزم اليسار في '],
      [/^Keep left/i, 'الزم اليسار'],
      [/^احفظ الشمال toward\s+/i, 'الزم اليسار باتجاه '],
      [/^احفظ الشمال خلال\s+/i, 'الزم اليسار عبر '],
      [/^احفظ الشمال/i, 'الزم اليسار'],

      // U-Turns
      [/^Make a U-turn\s+/i, 'قم بالدوران للخلف (U-turn) عند '],
      [/^Make a U-turn/i, 'قم بالدوران للخلف'],
      [/^U-turn/i, 'دوران للخلف'],

      // Head / Bearings
      [/^Head north onto\s+/i, 'اتجه شمالاً في '],
      [/^Head south onto\s+/i, 'اتجه جنوباً في '],
      [/^Head east onto\s+/i, 'اتجه شرقاً في '],
      [/^Head west onto\s+/i, 'اتجه غرباً في '],
      [/^Head northeast onto\s+/i, 'اتجه نحو الشمال الشرقي في '],
      [/^Head northwest onto\s+/i, 'اتجه نحو الشمال الغربي في '],
      [/^Head southeast onto\s+/i, 'اتجه نحو الجنوب الشرقي في '],
      [/^Head southwest onto\s+/i, 'اتجه نحو الجنوب الغربي في '],

      [/^Head north/i, 'اتجه شمالاً'],
      [/^Head south/i, 'اتجه جنوباً'],
      [/^Head east/i, 'اتجه شرقاً'],
      [/^Head west/i, 'اتجه غرباً'],
      [/^Head northeast/i, 'اتجه شمال شرق'],
      [/^Head northwest/i, 'اتجه شمال غرب'],
      [/^Head southeast/i, 'اتجه جنوب شرق'],
      [/^Head southwest/i, 'اتجه جنوب غرب'],

      // Toward / Onto / Through prepositions
      [/\btoward\b/gi, 'باتجاه'],
      [/\btowards\b/gi, 'باتجاه'],
      [/\bonto\b/gi, 'في'],
      [/\bthrough\b/gi, 'عبر'],

      // Destinations & Finish
      [/^Arrive at destination/i, 'الوصول إلى الوجهة'],
      [/^Reached destination/i, 'تم الوصول إلى الوجهة'],
      [/^Destination/i, 'الوصول إلى الوجهة'],
      [/^النهاية/i, 'الوصول إلى الوجهة']
    ];

    for (const [regex, replacement] of phrases) {
      text = text.replace(regex, replacement);
    }

    // Clean up excessive whitespace
    text = text.replace(/\s+/g, ' ').trim();

    return text;
  }

  /**
   * High-Precision Multi-Scale Topographic Elevation Model for Jordan
   * Combines regional DEM baseline with realistic wadi systems, ridge crests, and urban hill models (Amman 7 hills, Zarqa Basin & North).
   */
  private estimateElevation(lat: number, lng: number): number {
    // 1. Regional Base Elevation Surface (Western Rift to Eastern Desert)
    let baseElev = 750;
    
    // Rift Valley Depression (Jordan Valley / Dead Sea)
    if (lng < 35.65) {
      const riftDist = Math.max(0, Math.min(1, (35.65 - lng) / 0.15));
      const riftBottom = lat < 31.9 ? -420 : (lat < 32.3 ? -220 : -150);
      const highlandEdge = lat > 32.2 ? 1000 : (lat > 31.5 ? 900 : 1300);
      baseElev = highlandEdge - riftDist * (highlandEdge - riftBottom);
    } 
    // Western Highlands (Ajloun, Balqa, West Amman, Tafila, Dana, Petra)
    else if (lng >= 35.65 && lng < 35.88) {
      if (lat >= 32.25) baseElev = 950 + (lat - 32.25) * 150; // Ajloun / Jerash Highlands (950m - 1150m)
      else if (lat >= 31.85) baseElev = 920 + (lng - 35.75) * 400; // Balqa / West Amman (850m - 1040m)
      else if (lat >= 30.2) baseElev = 1100 + (31.85 - lat) * 150; // Shobak / Dana / Petra (1100m - 1550m)
      else baseElev = 800 - (30.2 - lat) * 700; // South towards Aqaba
    }
    // Central Urban Basin (East Amman, Zarqa, Rusaifa, Madaba, Irbid Plateau)
    else if (lng >= 35.88 && lng < 36.25) {
      if (lat >= 32.4) {
        baseElev = 580 + (lat - 32.4) * 80; // Irbid Plateau (580m - 620m)
      } else if (lat >= 32.0 && lat < 32.25) {
        // Zarqa & Sukhna River Basin (520m in river bed, 680m on surrounding hills)
        const riverAxisLat = 32.06 + (lng - 36.05) * 0.7; // Zarqa river path
        const distFromRiver = Math.abs(lat - riverAxisLat) * 111.32; // km from river
        const localWadiRelief = Math.min(140, distFromRiver * 70); // 0m in wadi, +140m on hill crests
        baseElev = 530 + localWadiRelief + (lng - 36.0) * 45;
      } else if (lat >= 31.85 && lat < 32.0) {
        // Amman 7 Hills & Valleys Topography
        const localAmmanHill = Math.sin((lat - 31.95) * 180) * 70 + Math.cos((lng - 35.92) * 180) * 60;
        baseElev = 840 - (lng - 35.90) * 350 + localAmmanHill;
      } else if (lat < 31.85 && lat >= 31.6) {
        baseElev = 740 + (lat - 31.6) * 100; // Airport / Madaba plains
      } else {
        baseElev = 700;
      }
    }
    // Eastern Desert Plateau (Mafraq, Azraq, Safawi)
    else {
      baseElev = 640 + (lng - 36.25) * 20 - (lat - 32.0) * 30;
    }

    return Math.round(baseElev);
  }

  private haversineDistance(lat1: number, lon1: number, lat2: number, lon2: number): number {
    const R = 6371000;
    const dLat = (lat2 - lat1) * (Math.PI / 180);
    const dLon = (lon2 - lon1) * (Math.PI / 180);
    const a =
      Math.sin(dLat / 2) * Math.sin(dLat / 2) +
      Math.cos(lat1 * (Math.PI / 180)) * Math.cos(lat2 * (Math.PI / 180)) *
      Math.sin(dLon / 2) * Math.sin(dLon / 2);
    return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
  }

  /**
   * Intelligently extracts the most descriptive, distinctive street or highway name for a route.
   */
  private getRouteName(instructions: any[], excludeStreet?: string): string | null {
    if (!instructions || instructions.length === 0) return null;
    
    const streetDistances: Record<string, number> = {};
    
    for (const inst of instructions) {
      let candidate = inst.street_name?.trim();
      
      // If street_name is empty, check highway ref or destination (e.g., Highway 35 / طريق جرش / طريق المطار)
      if (!candidate || candidate === '') {
        if (inst.street_destination_ref) {
          candidate = `طريق ${inst.street_destination_ref}`;
        } else if (inst.street_ref) {
          candidate = `طريق ${inst.street_ref}`;
        } else if (inst.street_destination) {
          candidate = `طريق ${inst.street_destination}`;
        }
      }

      // If still empty, attempt to extract named street from instruction text
      if (!candidate || candidate === '') {
        const match = inst.text?.match(/(?:عبر|في|إلى|خلال|من خلال)\s+(شارع\s+[\u0621-\u064A0-9\s]+|طريق\s+[\u0621-\u064A0-9\s]+|دوار\s+[\u0621-\u064A0-9\s]+|الدوار\s+[\u0621-\u064A0-9\s]+|جسر\s+[\u0621-\u064A0-9\s]+)/i);
        if (match && match[1]) {
          candidate = match[1].trim();
        }
      }

      if (candidate && candidate !== '') {
        // Remove trailing or leading noise
        candidate = candidate.replace(/^عبر\s+/, '').trim();
        
        // If we have an exclusion, only add if different
        if (!excludeStreet || candidate !== excludeStreet.replace(/^عبر\s+/, '').trim()) {
          streetDistances[candidate] = (streetDistances[candidate] || 0) + (inst.distance || 1);
        }
      }
    }

    // Pick candidate with longest distance
    let longestStreet: string | null = null;
    let maxDist = 0;
    
    for (const [street, dist] of Object.entries(streetDistances)) {
      if (dist > maxDist) {
        maxDist = dist;
        longestStreet = street;
      }
    }
    
    // If no non-excluded street found, fallback to any longest street
    if (!longestStreet && excludeStreet) {
      return this.getRouteName(instructions);
    }
    
    return longestStreet;
  }

  /**
   * Manual decoder for Google Polyline algorithm (Server-side spatial matching)
   */
  private decodePolyline(encoded: string): [number, number][] {
    const points: [number, number][] = [];
    let index = 0, len = encoded.length;
    let lat = 0, lng = 0;

    while (index < len) {
      let b, shift = 0, result = 0;
      do {
        b = encoded.charCodeAt(index++) - 63;
        result |= (b & 0x1f) << shift;
        shift += 5;
      } while (b >= 0x20);
      let dlat = ((result & 1) ? ~(result >> 1) : (result >> 1));
      lat += dlat;

      shift = 0;
      result = 0;
      do {
        b = encoded.charCodeAt(index++) - 63;
        result |= (b & 0x1f) << shift;
        shift += 5;
      } while (b >= 0x20);
      let dlng = ((result & 1) ? ~(result >> 1) : (result >> 1));
      lng += dlng;

      points.push([lng * 1e-5, lat * 1e-5]);
    }
    return points;
  }

  async getMapConfig() {
    return {
      center: [31.95, 35.91],
      zoom: 12,
      tileServerUrl: this.configService.get('TILE_SERVER_URL', 'http://localhost:3001'),
    };
  }
}