import { HttpClient, HttpParams } from '@angular/common/http';
import { Injectable, inject } from '@angular/core';
import { Observable } from 'rxjs';
import { FileDownloadService } from './file-download.service';

export type LeaseEndPhase =
  'ACTIVE' | 'NOTICE_PERIOD' | 'AWAITING_CLOSURE' | 'UNAUTHORIZED_OCCUPANCY' | 'ARCHIVED';

export type NoticeDeliveryMode = 'REGISTERED_LETTER' | 'BAILIFF' | 'HAND_DELIVERY' | 'OTHER';

export interface LeaseEndEvidence {
  version: number;
  fileName: string;
  contentType: string;
  size: number;
  sha256: string;
  reason: string | null;
  authorId: string;
  recordedAt: string;
}

export interface LeaseEndAudit {
  authorId: string;
  recordedAt: string;
}

export interface LeaseEndNotice {
  id: string;
  status: 'ACTIVE' | 'WITHDRAWN' | 'INVALIDATED';
  receivedOn: string;
  requestedDepartureOn: string;
  deliveryMode: NoticeDeliveryMode;
  otherDeliveryMode: string | null;
  noticeMonths: number;
  minimumEndOn: string;
  ruleVersion: string;
  recordedWithoutEvidenceConfirmed: boolean;
  authorId: string;
  recordedAt: string;
  evidenceVersions: LeaseEndEvidence[];
  withdrawal: (LeaseEndAudit & { acceptedOn: string; reason: string }) | null;
  invalidation: (LeaseEndAudit & { invalidatedOn: string; reason: string }) | null;
}

export interface LeaseEndState {
  leaseId: string;
  supported: boolean;
  unsupportedReason: string | null;
  phase: LeaseEndPhase;
  leaseType: 'STANDARD' | 'STUDENT';
  fixedEndOn: string | null;
  effectiveEndOn: string | null;
  correctionRequired: boolean;
  exitConditionReport: {
    occurredOn: string;
    finalized: boolean;
  } | null;
  notices: LeaseEndNotice[];
  agreedEarlyEnds: LeaseEndAgreement[];
  agreedEarlyEnd: LeaseEndAgreement | null;
  closure: {
    keysReturnedOn: string;
    authorId: string;
    recordedAt: string;
  } | null;
}

export interface LeaseEndAgreement {
  endOn: string;
  reason: string;
  authorId: string;
  recordedAt: string;
}

export interface RecordNoticeRequest {
  timeZone: string;
  receivedOn: string;
  requestedDepartureOn: string;
  deliveryMode: NoticeDeliveryMode;
  otherDeliveryMode?: string;
  lateRegistrationConfirmed: boolean;
  nonStandardDeliveryConfirmed: boolean;
  missingEvidenceConfirmed: boolean;
  evidence?: File;
}

export interface AcceptWithdrawalRequest {
  timeZone: string;
  acceptedOn: string;
  reason: string;
}

export interface InvalidateNoticeRequest {
  timeZone: string;
  invalidatedOn: string;
  reason: string;
}

export interface AppendEvidenceRequest {
  timeZone: string;
  evidence: File;
  reason?: string;
}

export interface AgreedEarlyEndRequest {
  timeZone: string;
  endOn: string;
  reason: string;
}

export interface CloseLeaseRequest {
  timeZone: string;
  confirmed: true;
}

@Injectable({ providedIn: 'root' })
export class LeaseEndService {
  private readonly http = inject(HttpClient);
  private readonly downloads = inject(FileDownloadService);

  getState(leaseId: string, timeZone: string): Observable<LeaseEndState> {
    const params = new HttpParams().set('timeZone', timeZone);
    return this.http.get<LeaseEndState>(`/api/leases/${leaseId}/end`, { params });
  }

  recordNotice(leaseId: string, request: RecordNoticeRequest): Observable<LeaseEndState> {
    return this.http.post<LeaseEndState>(
      `/api/leases/${leaseId}/end/notices`,
      noticeFormData(request),
    );
  }

  acceptWithdrawal(
    leaseId: string,
    noticeId: string,
    request: AcceptWithdrawalRequest,
  ): Observable<LeaseEndState> {
    return this.http.post<LeaseEndState>(
      `/api/leases/${leaseId}/end/notices/${noticeId}/withdrawals`,
      request,
    );
  }

  invalidateNotice(
    leaseId: string,
    noticeId: string,
    request: InvalidateNoticeRequest,
  ): Observable<LeaseEndState> {
    return this.http.post<LeaseEndState>(
      `/api/leases/${leaseId}/end/notices/${noticeId}/invalidations`,
      request,
    );
  }

  appendEvidence(
    leaseId: string,
    noticeId: string,
    request: AppendEvidenceRequest,
  ): Observable<LeaseEndState> {
    const formData = new FormData();
    formData.append('timeZone', request.timeZone);
    formData.append('evidence', request.evidence);
    if (request.reason) formData.append('reason', request.reason);
    return this.http.post<LeaseEndState>(
      `/api/leases/${leaseId}/end/notices/${noticeId}/evidence`,
      formData,
    );
  }

  downloadEvidence(leaseId: string, noticeId: string, version: number, fileName: string): void {
    const key = this.evidenceDownloadKey(leaseId, noticeId, version);
    this.downloads.download(
      key,
      this.http.get(`/api/leases/${leaseId}/end/notices/${noticeId}/evidence/${version}`, {
        responseType: 'blob',
      }),
      fileName,
      'Impossible de télécharger cette preuve.',
    );
  }

  evidenceDownloading(leaseId: string, noticeId: string, version: number): boolean {
    return this.downloads.isPending(this.evidenceDownloadKey(leaseId, noticeId, version));
  }

  evidenceDownloadError(leaseId: string, noticeId: string, version: number): string {
    return this.downloads.error(this.evidenceDownloadKey(leaseId, noticeId, version));
  }

  recordAgreedEarlyEnd(leaseId: string, request: AgreedEarlyEndRequest): Observable<LeaseEndState> {
    return this.http.post<LeaseEndState>(`/api/leases/${leaseId}/end/agreed-early-end`, request);
  }

  close(leaseId: string, request: CloseLeaseRequest): Observable<LeaseEndState> {
    return this.http.post<LeaseEndState>(`/api/leases/${leaseId}/end/closure`, request);
  }

  private evidenceDownloadKey(leaseId: string, noticeId: string, version: number): string {
    return `lease-end-evidence:${leaseId}:${noticeId}:${version}`;
  }
}

function noticeFormData(request: RecordNoticeRequest): FormData {
  const formData = new FormData();
  formData.append('timeZone', request.timeZone);
  formData.append('receivedOn', request.receivedOn);
  formData.append('requestedDepartureOn', request.requestedDepartureOn);
  formData.append('deliveryMode', request.deliveryMode);
  if (request.otherDeliveryMode) formData.append('otherDeliveryMode', request.otherDeliveryMode);
  formData.append('lateRegistrationConfirmed', String(request.lateRegistrationConfirmed));
  formData.append('nonStandardDeliveryConfirmed', String(request.nonStandardDeliveryConfirmed));
  formData.append('missingEvidenceConfirmed', String(request.missingEvidenceConfirmed));
  if (request.evidence) formData.append('evidence', request.evidence);
  return formData;
}