import { Component, ChangeDetectorRef, OnInit } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { AssignedRouteComponent } from './assigned-route/assigned-route.component';
import { NoAssignedRouteComponent } from './no-assigned-route/no-assigned-route.component';
import { RutasService } from '../../core/services/router.service';
import { RouteState } from '../../core/route-state/route';
import { ApiResponse } from '../../core/models/route.model';
import { ExcelPreviewService, PreviewResult } from '../../shared/services/excel-preview.service';
import { Subscription } from 'rxjs';
import { PlanningKpisComponent } from './planning-kpis/planning-kpis.component';
import { PlanningInputService } from '../../core/services/planning-input.service';
import { RouterLink } from '@angular/router';
import { EmployeeService } from '../../core/services/employee.service';

@Component({
  standalone: true,
  selector: 'app-home',
  imports: [CommonModule, FormsModule, RouterLink, AssignedRouteComponent, NoAssignedRouteComponent, PlanningKpisComponent],
  templateUrl: './home.component.html',
  styleUrls: ['./home.component.css']
})
export class HomeComponent implements OnInit {
  pdvFile: File | null = null;
  usuariosFile: File | null = null;
  pdvPreview: PreviewResult | null = null;
  usuariosPreview: PreviewResult | null = null;
  pdvPreviewLoading = false;
  usuariosPreviewLoading = false;
  activeEmployees = 0;
  employeesLoading = true;
  uploadError: string | null = null;
  isLoading = false;
  private calcSub: Subscription | null = null;

  constructor(
    private rutasService: RutasService,
    private routeState: RouteState,
    private previewService: ExcelPreviewService,
    private planningInput: PlanningInputService,
    private employeesService: EmployeeService,
    private cdr: ChangeDetectorRef
  ) {}

  ngOnInit(): void {
    void this.loadEmployees();
  }

  private async loadEmployees(): Promise<void> {
    this.employeesLoading = true;
    try {
      this.activeEmployees = (await this.employeesService.list()).filter(employee => employee.activo).length;
    } catch {
      this.activeEmployees = 0;
    } finally {
      this.employeesLoading = false;
      this.cdr.detectChanges();
    }
  }

  async onPdvFileChange(event: Event) {
    const input = event.target as HTMLInputElement;
    if (input.files && input.files.length > 0) {
      const file = input.files[0];
      const basicError = this.validateFileBasic(file, 'PDV');
      if (basicError) {
        this.pdvFile = null;
        this.pdvPreview = null;
        this.uploadError = basicError;
        return;
      }
      this.pdvFile = file;
      if (this.usuariosFile) this.planningInput.setFiles(file, this.usuariosFile);
      this.uploadError = null;
      this.pdvPreviewLoading = true;
      this.pdvPreview = null;
      this.cdr.detectChanges();
      try {
        this.pdvPreview = await this.previewService.previewFile(file, 'PDV');
      } catch (e: unknown) {
        const msg = e instanceof Error ? e.message : 'Error al leer el archivo PDV';
        this.pdvPreview = {
          fileName: file.name,
          type: 'PDV',
          valid: false,
          totalRows: 0,
          validRows: 0,
          headers: [],
          normalizedHeaders: [],
          missingHeaders: [],
          errors: [{ row: 1, field: 'file', message: msg }],
          duplicateIds: [],
          sampleValidRows: [],
        };
      } finally {
        this.pdvPreviewLoading = false;
        this.cdr.detectChanges();
      }
    }
  }

  async onUsuariosFileChange(event: Event) {
    const input = event.target as HTMLInputElement;
    if (input.files && input.files.length > 0) {
      const file = input.files[0];
      const basicError = this.validateFileBasic(file, 'Usuarios');
      if (basicError) {
        this.usuariosFile = null;
        this.usuariosPreview = null;
        this.uploadError = basicError;
        return;
      }
      this.usuariosFile = file;
      if (this.pdvFile) this.planningInput.setFiles(this.pdvFile, file);
      this.uploadError = null;
      this.usuariosPreviewLoading = true;
      this.usuariosPreview = null;
      this.cdr.detectChanges();
      try {
        this.usuariosPreview = await this.previewService.previewFile(file, 'Usuarios');
      } catch (e: unknown) {
        const msg = e instanceof Error ? e.message : 'Error al leer el archivo Usuarios';
        this.usuariosPreview = {
          fileName: file.name,
          type: 'Usuarios',
          valid: false,
          totalRows: 0,
          validRows: 0,
          headers: [],
          normalizedHeaders: [],
          missingHeaders: [],
          errors: [{ row: 1, field: 'file', message: msg }],
          duplicateIds: [],
          sampleValidRows: [],
        };
      } finally {
        this.usuariosPreviewLoading = false;
        this.cdr.detectChanges();
      }
    }
  }

  private validateFileBasic(file: File, type: string): string | null {
    const validExtensions = ['.xlsx', '.xls'];
    const ext = file.name.substring(file.name.lastIndexOf('.')).toLowerCase();
    if (!validExtensions.includes(ext)) {
      return `El archivo ${type} debe ser .xlsx o .xls`;
    }
    if (file.size > 10 * 1024 * 1024) {
      return `El archivo ${type} supera 10MB`;
    }
    return null;
  }

  get canSubmit(): boolean {
    if (!this.pdvFile || !this.activeEmployees) return false;
    if (this.pdvPreviewLoading || this.employeesLoading) return false;
    if (this.isLoading) return false;
    if (this.uploadError) return false;
    // Require valid previews before enabling submit
    if (this.pdvPreview && !this.pdvPreview.valid) return false;
    if (!this.pdvPreview) return false;
    return true;
  }

  get submitDisabledReason(): string | null {
    if (!this.pdvFile) return 'Sube el archivo PDV';
    if (this.employeesLoading) return 'Cargando empleados...';
    if (!this.activeEmployees) return 'No hay empleados activos. Regístralos en Gestionar empleados.';
    if (this.pdvPreviewLoading) return 'Validando archivo PDV...';
    if (this.pdvPreview && !this.pdvPreview.valid) return 'Corrige los errores del archivo PDV';
    return null;
  }

  async cargarRutas() {
    if (!this.canSubmit) return;

    this.isLoading = true;
    this.uploadError = null;
    this.routeState.setLoading(true);
    let pdvForOptimizer: File;
    try {
      pdvForOptimizer = await this.previewService.preparePdvForOptimizer(this.pdvFile!);
    } catch {
      this.uploadError = 'No se pudo preparar el archivo PDV para el optimizador.';
      this.routeState.setLoading(false);
      this.isLoading = false;
      this.cdr.detectChanges();
      return;
    }
    let employeesFile: File;
    try {
      employeesFile = await this.employeesService.activeEmployeesFile();
    } catch {
      this.uploadError = 'No se pudieron obtener los empleados activos.';
      this.routeState.setLoading(false);
      this.isLoading = false;
      return;
    }
    this.planningInput.setFiles(pdvForOptimizer, employeesFile);

    const formData = new FormData();
    formData.append('pdv_file', pdvForOptimizer, pdvForOptimizer.name);
    formData.append('usuarios_file', employeesFile, employeesFile.name);

    this.calcSub?.unsubscribe();
    this.calcSub = this.rutasService.calcularRutas(formData).subscribe({
      next: (res: ApiResponse) => {
        // ApiResponse is [AssignedResponse, NoAssignedResponse] but backend may return object with error
        const anyRes = res as unknown as Record<string, unknown>;
        if (anyRes && 'error' in anyRes) {
          this.uploadError = String((anyRes as { error: unknown }).error);
          this.routeState.setLoading(false);
          this.isLoading = false;
          this.cdr.detectChanges();
          return;
        }
        const arr = res as unknown as unknown[];
        const assigned = (arr as ApiResponse).find(r => r && typeof r === 'object' && 'assigned' in r) as unknown as { assigned: unknown } | undefined;
        const noAssigned = (arr as ApiResponse).find(r => r && typeof r === 'object' && 'noAssigned' in r) as unknown as { noAssigned: unknown } | undefined;
        if (assigned) {
          this.routeState.setAssignedRoutes(assigned.assigned as never);
        }
        if (noAssigned) {
          this.routeState.setNoAssignedRoutes(noAssigned.noAssigned as never);
        }
        this.routeState.setLoading(false);
        this.isLoading = false;
        this.cdr.detectChanges();
      },
      error: (err) => {
        this.uploadError = this.mapBackendError(err);
        this.routeState.setLoading(false);
        this.isLoading = false;
        this.cdr.detectChanges();
      }
    });
  }

  cancelarCarga() {
    this.calcSub?.unsubscribe();
    this.calcSub = null;
    this.isLoading = false;
    this.routeState.setLoading(false);
    this.uploadError = 'Cálculo cancelado';
  }

  private mapBackendError(err: unknown): string {
    const anyErr = err as { error?: { error?: string; message?: string }; message?: string; status?: number; name?: string };
    if (anyErr?.name === 'TimeoutError') return 'El cálculo tardó demasiado (timeout 30s). Intenta de nuevo con menos filas.';
    if (anyErr?.error?.error) return anyErr.error.error;
    if (anyErr?.error?.message) return anyErr.error.message;
    if (anyErr?.message) return anyErr.message;
    return 'Error al procesar los archivos';
  }

  clearFiles() {
    this.calcSub?.unsubscribe();
    this.planningInput.clear();
    this.routeState.clearAll();
    this.pdvFile = null;
    this.usuariosFile = null;
    this.pdvPreview = null;
    this.usuariosPreview = null;
    this.pdvPreviewLoading = false;
    this.usuariosPreviewLoading = false;
    this.uploadError = null;
    this.isLoading = false;
    this.routeState.setLoading(false);
    const pdvInput = document.getElementById('pdvFile') as HTMLInputElement;
    const usuariosInput = document.getElementById('usuariosFile') as HTMLInputElement;
    if (pdvInput) pdvInput.value = '';
    if (usuariosInput) usuariosInput.value = '';
  }
}