import {
  ChangeDetectionStrategy,
  Component,
  computed,
  inject,
  OnInit,
  signal,
} from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { LiveDataService } from '../../core/services/live-data.service';
import { PvHistoryData, PvHistoryEntry } from '../../core/models/pv-data.model';
import { LoadingSpinnerComponent, ErrorMessageComponent } from '../../shared';
import { DecimalPipe, DatePipe } from '@angular/common';

type Resolution = 'hour' | 'day' | 'month' | 'year';

@Component({
  selector: 'app-plant-history',
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [LoadingSpinnerComponent, ErrorMessageComponent, DecimalPipe, DatePipe],
  templateUrl: './plant-history.component.html',
  styleUrl: './plant-history.component.scss',
})
export class PlantHistoryComponent implements OnInit {
  private readonly route = inject(ActivatedRoute);
  private readonly liveDataService = inject(LiveDataService);

  readonly resolution = signal<Resolution>('day');
  readonly historyData = signal<PvHistoryData | null>(null);
  readonly loading = signal(false);
  readonly error = signal<string | null>(null);

  readonly resolutions: { value: Resolution; label: string }[] = [
    { value: 'hour', label: 'Stündlich' },
    { value: 'day',  label: 'Täglich' },
    { value: 'month', label: 'Monatlich' },
    { value: 'year', label: 'Jährlich' },
  ];

  readonly totalEnergy = computed(() =>
    this.historyData()?.entries.reduce((sum, e) => sum + e.energyKwh, 0) ?? 0
  );

  readonly peakEntry = computed(() => {
    const entries = this.historyData()?.entries ?? [];
    if (!entries.length) return null;
    return entries.reduce((max, e) => (e.peakPowerKw > max.peakPowerKw ? e : max));
  });

  readonly chartBarData = computed(() => {
    const entries = this.historyData()?.entries ?? [];
    if (!entries.length) return [];
    const max = Math.max(...entries.map((e) => e.energyKwh));
    return entries.map((e) => ({
      ...e,
      barPercent: max > 0 ? (e.energyKwh / max) * 100 : 0,
    }));
  });

  private plantId = '';

  ngOnInit(): void {
    // plantId kommt vom Parent-Route-Snapshot (plant-shell)
    this.plantId =
      this.route.parent?.snapshot.paramMap.get('id') ??
      this.route.snapshot.paramMap.get('id') ??
      '';
    this.loadHistory();
  }

  loadHistory(): void {
    if (!this.plantId) return;
    this.loading.set(true);
    this.error.set(null);
    this.liveDataService.getHistory(this.plantId, this.resolution()).subscribe({
      next: (data) => {
        this.historyData.set(data);
        this.loading.set(false);
      },
      error: () => {
        this.error.set('Verlaufsdaten konnten nicht geladen werden.');
        this.loading.set(false);
      },
    });
  }

  setResolution(res: Resolution): void {
    this.resolution.set(res);
    this.loadHistory();
  }

  dateFormat(resolution: Resolution): string {
    switch (resolution) {
      case 'hour':  return 'dd.MM.yy HH:mm';
      case 'day':   return 'dd.MM.yyyy';
      case 'month': return 'MMM yyyy';
      case 'year':  return 'yyyy';
    }
  }
}