/**
 * Backend API client for RFCP coverage calculation
 */
import { getApiBaseUrl } from '@/lib/desktop.ts';

const API_BASE = getApiBaseUrl();

// === Request types ===

export interface ApiSiteParams {
  lat: number;
  lon: number;
  height: number;
  power: number;     // dBm
  gain: number;      // dBi
  frequency: number; // MHz
  azimuth?: number;
  beamwidth?: number;
}

export interface ApiCoverageSettings {
  radius: number;      // meters
  resolution: number;  // meters
  min_signal: number;  // dBm
  preset?: 'fast' | 'standard' | 'detailed' | 'full';
  use_terrain?: boolean;
  use_buildings?: boolean;
  use_materials?: boolean;
  use_dominant_path?: boolean;
  use_street_canyon?: boolean;
  use_reflections?: boolean;
  use_water_reflection?: boolean;
  use_vegetation?: boolean;
  season?: 'summer' | 'winter' | 'spring' | 'autumn';
  rain_rate?: number;
  indoor_loss_type?: string;
  use_atmospheric?: boolean;
  temperature_c?: number;
  humidity_percent?: number;
}

export interface CoverageRequest {
  sites: ApiSiteParams[];
  settings: ApiCoverageSettings;
}

// === Response types ===

export interface ApiCoveragePoint {
  lat: number;
  lon: number;
  rsrp: number;
  distance: number;
  has_los: boolean;
  terrain_loss: number;
  building_loss: number;
  reflection_gain: number;
  vegetation_loss: number;
  rain_loss: number;
  indoor_loss: number;
  atmospheric_loss: number;
}

export interface ApiCoverageStats {
  min_rsrp: number;
  max_rsrp: number;
  avg_rsrp: number;
  los_percentage: number;
  points_with_buildings: number;
  points_with_terrain_loss: number;
  points_with_reflection_gain: number;
  points_with_vegetation_loss: number;
  points_with_rain_loss: number;
  points_with_indoor_loss: number;
  points_with_atmospheric_loss: number;
}

export interface CoverageResponse {
  points: ApiCoveragePoint[];
  count: number;
  settings: ApiCoverageSettings;
  stats: ApiCoverageStats;
  computation_time: number;
  models_used: string[];
}

export interface Preset {
  description: string;
  use_terrain: boolean;
  use_buildings: boolean;
  use_materials: boolean;
  use_dominant_path: boolean;
  use_street_canyon: boolean;
  use_reflections: boolean;
  use_water_reflection: boolean;
  use_vegetation: boolean;
  estimated_speed: string;
}

// === Elevation grid types ===

export interface ElevationGridResponse {
  grid: number[][];
  rows: number;
  cols: number;
  min_elevation: number;
  max_elevation: number;
  bbox: {
    min_lat: number;
    max_lat: number;
    min_lon: number;
    max_lon: number;
  };
}

// === API Client ===

class ApiService {
  private abortController: AbortController | null = null;

  async getPresets(): Promise<Record<string, Preset>> {
    const response = await fetch(`${API_BASE}/api/coverage/presets`);
    if (!response.ok) throw new Error('Failed to fetch presets');
    const data = await response.json();
    return data.presets;
  }

  async calculateCoverage(request: CoverageRequest): Promise<CoverageResponse> {
    // Cancel previous request if running
    if (this.abortController) {
      this.abortController.abort();
    }
    this.abortController = new AbortController();

    const response = await fetch(`${API_BASE}/api/coverage/calculate`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(request),
      signal: this.abortController.signal,
    });

    if (!response.ok) {
      const error = await response.json().catch(() => ({ detail: 'Coverage calculation failed' }));
      throw new Error(error.detail || 'Coverage calculation failed');
    }

    this.abortController = null;
    return response.json();
  }

  cancelCalculation() {
    if (this.abortController) {
      this.abortController.abort();
      this.abortController = null;
    }
  }

  async getElevation(lat: number, lon: number): Promise<number> {
    const response = await fetch(
      `${API_BASE}/api/terrain/elevation?lat=${lat}&lon=${lon}`
    );
    if (!response.ok) return 0;
    const data = await response.json();
    return data.elevation;
  }

  async getElevationGrid(
    minLat: number,
    maxLat: number,
    minLon: number,
    maxLon: number,
    resolution: number = 100,
  ): Promise<ElevationGridResponse> {
    const params = new URLSearchParams({
      min_lat: minLat.toString(),
      max_lat: maxLat.toString(),
      min_lon: minLon.toString(),
      max_lon: maxLon.toString(),
      resolution: resolution.toString(),
    });
    const response = await fetch(
      `${API_BASE}/api/terrain/elevation-grid?${params}`
    );
    if (!response.ok) throw new Error('Failed to fetch elevation grid');
    return response.json();
  }

  // === Region / Caching API ===

  async getRegions(): Promise<RegionInfo[]> {
    const response = await fetch(`${API_BASE}/api/regions/available`);
    if (!response.ok) throw new Error('Failed to fetch regions');
    return response.json();
  }

  async downloadRegion(regionId: string): Promise<{ task_id: string; status: string }> {
    const response = await fetch(`${API_BASE}/api/regions/download/${regionId}`, {
      method: 'POST',
    });
    if (!response.ok) throw new Error('Failed to start download');
    return response.json();
  }

  async getDownloadProgress(taskId: string): Promise<DownloadProgress> {
    const response = await fetch(`${API_BASE}/api/regions/download/${taskId}/progress`);
    if (!response.ok) throw new Error('Failed to get progress');
    return response.json();
  }

  async getCacheStats(): Promise<CacheStats> {
    const response = await fetch(`${API_BASE}/api/regions/cache/stats`);
    if (!response.ok) throw new Error('Failed to get cache stats');
    return response.json();
  }

  // === GPU API ===

  async getGPUStatus(): Promise<GPUStatus> {
    const response = await fetch(`${API_BASE}/api/gpu/status`);
    if (!response.ok) throw new Error('Failed to get GPU status');
    return response.json();
  }

  async getGPUDevices(): Promise<{ devices: GPUDevice[] }> {
    const response = await fetch(`${API_BASE}/api/gpu/devices`);
    if (!response.ok) throw new Error('Failed to get GPU devices');
    return response.json();
  }

  async setGPUDevice(backend: string, index: number = 0): Promise<{ status: string; backend: string; device: string }> {
    const response = await fetch(`${API_BASE}/api/gpu/set`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ backend, index }),
    });
    if (!response.ok) {
      const err = await response.json().catch(() => ({ detail: 'Failed to set GPU device' }));
      throw new Error(err.detail || 'Failed to set GPU device');
    }
    return response.json();
  }

  // === Terrain Profile API ===

  async getTerrainProfile(
    lat1: number, lon1: number,
    lat2: number, lon2: number,
    points: number = 100,
  ): Promise<TerrainProfilePoint[]> {
    const params = new URLSearchParams({
      lat1: lat1.toString(),
      lon1: lon1.toString(),
      lat2: lat2.toString(),
      lon2: lon2.toString(),
      points: points.toString(),
    });
    const response = await fetch(`${API_BASE}/api/terrain/profile?${params}`);
    if (!response.ok) throw new Error('Failed to get terrain profile');
    const data = await response.json();
    return data.profile ?? data;
  }
}

// === Region types ===

export interface RegionInfo {
  id: string;
  name: string;
  bbox: number[];
  srtm_tiles: number;
  estimated_size_gb: number;
  downloaded: boolean;
  download_progress: number;
}

export interface DownloadProgress {
  task_id: string;
  region_id: string;
  status: string;
  progress: number;
  current_step: string;
  downloaded_mb: number;
  error?: string;
}

export interface CacheStats {
  terrain_mb: number;
  terrain_tiles: number;
  buildings_mb: number;
  water_mb: number;
  vegetation_mb: number;
}

// === GPU types ===

export interface GPUDevice {
  backend: string;
  index: number;
  name: string;
  memory_mb: number;
}

export interface GPUStatus {
  active_backend: string;
  active_device: GPUDevice | null;
  gpu_available: boolean;
  available_devices: GPUDevice[];
}

// === Terrain Profile types ===

export interface TerrainProfilePoint {
  lat: number;
  lon: number;
  elevation: number;
  distance: number;
}

export const api = new ApiService();