// API client module: thin typed fetch wrappers over the contract endpoints.
// Base URL from VITE_API_BASE, defaulting to http://localhost:8000/api.

import type {
  AiAssistResponse,
  Application,
  Approval,
  Artifact,
  BatchScoringResponse,
  CoverLetterResponse,
  CritiqueComment,
  CvImportConfirmResponse,
  CvImportResponse,
  CvSection,
  DemoSeedResponse,
  InterviewPrepResponse,
  JobPosting,
  PostingsFetchResponse,
  Profile,
  RenderCvResponse,
  ScoreResponse,
  TaskRun,
  TodayResponse
} from '@/types'

const API_BASE: string =
  import.meta.env.VITE_API_BASE ?? 'http://localhost:8000/api'

export class HttpError extends Error {
  status: number
  body: unknown
  constructor(status: number, body: unknown, message?: string) {
    super(message ?? `HTTP ${status}`)
    this.status = status
    this.body = body
  }
}

async function request<T>(
  path: string,
  options: RequestInit = {}
): Promise<T> {
  const res = await fetch(`${API_BASE}${path}`, {
    headers: { 'Content-Type': 'application/json', ...options.headers },
    ...options
  })
  if (!res.ok) {
    let body: unknown = null
    try {
      body = await res.json()
    } catch {
      // non-JSON error body
    }
    throw new HttpError(res.status, body, `HTTP ${res.status}`)
  }
  return res.json() as Promise<T>
}

// --- Profile & CV ---

export function getProfile(): Promise<Profile> {
  return request<Profile>('/profile')
}

export function updateProfile(data: Partial<Profile>): Promise<Profile> {
  return request<Profile>('/profile', { method: 'PUT', body: JSON.stringify(data) })
}

export function getSections(): Promise<CvSection[]> {
  return request<CvSection[]>('/profile/sections')
}

export function createSection(data: Partial<CvSection>): Promise<CvSection> {
  return request<CvSection>('/profile/sections', { method: 'POST', body: JSON.stringify(data) })
}

export function updateSection(id: string, data: Partial<CvSection>): Promise<CvSection> {
  return request<CvSection>(`/profile/sections/${id}`, { method: 'PUT', body: JSON.stringify(data) })
}

export function deleteSection(id: string): Promise<void> {
  return request<void>(`/profile/sections/${id}`, { method: 'DELETE' })
}

export function aiAssist(sectionId: string, instruction: string): Promise<AiAssistResponse> {
  return request<AiAssistResponse>(`/profile/sections/${sectionId}/ai-assist`, {
    method: 'POST',
    body: JSON.stringify({ instruction })
  })
}

export function renderCv(): Promise<RenderCvResponse> {
  return request<RenderCvResponse>('/profile/render-cv', { method: 'POST' })
}

// --- Job postings ---

export function getPostings(): Promise<JobPosting[]> {
  return request<JobPosting[]>('/postings')
}

export function createPosting(url: string): Promise<JobPosting> {
  return request<JobPosting>('/postings', { method: 'POST', body: JSON.stringify({ url }) })
}

export function scorePosting(postingId: string): Promise<ScoreResponse> {
  return request<ScoreResponse>(`/postings/${postingId}/score`, { method: 'POST' })
}

// --- Applications ---

export function getApplications(): Promise<Application[]> {
  return request<Application[]>('/applications')
}

export function transitionApplication(id: string, to: string): Promise<Application> {
  return request<Application>(`/applications/${id}/transition`, {
    method: 'POST',
    body: JSON.stringify({ to })
  })
}

export function getArtifacts(applicationId: string): Promise<Artifact[]> {
  return request<Artifact[]>(`/applications/${applicationId}/artifacts`)
}

export function createCoverLetter(
  applicationId: string,
  letterText: string
): Promise<CoverLetterResponse> {
  return request<CoverLetterResponse>(`/applications/${applicationId}/artifacts/cover-letter`, {
    method: 'POST',
    body: JSON.stringify({ letter_text: letterText })
  })
}

// --- Approval & outbox ---

export function createApproval(
  applicationId: string,
  action: string,
  artifactId: string
): Promise<Approval> {
  return request<Approval>(`/applications/${applicationId}/approvals`, {
    method: 'POST',
    body: JSON.stringify({ action, artifact_id: artifactId })
  })
}

export function confirmApproval(approvalId: string): Promise<Approval> {
  return request<Approval>(`/approvals/${approvalId}/confirm`, { method: 'POST' })
}

export function rejectApproval(approvalId: string): Promise<Approval> {
  return request<Approval>(`/approvals/${approvalId}/reject`, { method: 'POST' })
}

export function outboxSend(approvalId: string, payload: Record<string, unknown>): Promise<unknown> {
  return request<unknown>('/outbox/send', {
    method: 'POST',
    body: JSON.stringify({ approval_id: approvalId, payload })
  })
}

// --- Telemetry ---

export function getTelemetryTasks(): Promise<TaskRun[]> {
  return request<TaskRun[]>('/telemetry/tasks')
}

// --- v1.0 additions (api-contract-v2.md) ---

export function importCv(filename: string, contentBase64: string): Promise<CvImportResponse> {
  return request<CvImportResponse>('/cv/import', {
    method: 'POST',
    body: JSON.stringify({ filename, content_base64: contentBase64 })
  })
}

export function confirmCvImport(drafts: CvImportResponse['drafts']): Promise<CvImportConfirmResponse> {
  return request<CvImportConfirmResponse>('/cv/import/confirm', {
    method: 'POST',
    body: JSON.stringify({ drafts })
  })
}

export function fetchPostings(query: string, region?: string): Promise<PostingsFetchResponse> {
  const body: Record<string, string> = { query }
  if (region) body.region = region
  return request<PostingsFetchResponse>('/postings/fetch', {
    method: 'POST',
    body: JSON.stringify(body)
  })
}

export function batchScore(applicationIds: string[]): Promise<BatchScoringResponse> {
  return request<BatchScoringResponse>('/scoring/batch', {
    method: 'POST',
    body: JSON.stringify({ application_ids: applicationIds })
  })
}

export function getToday(): Promise<TodayResponse> {
  return request<TodayResponse>('/today')
}

export function interviewPrep(applicationId: string): Promise<InterviewPrepResponse> {
  return request<InterviewPrepResponse>(`/applications/${applicationId}/interview-prep`, {
    method: 'POST'
  })
}

export function seedDemo(): Promise<DemoSeedResponse> {
  return request<DemoSeedResponse>('/concierge/seed-demo', { method: 'POST' })
}

// Re-export types for convenience
export type {
  AiAssistResponse,
  Application,
  Approval,
  Artifact,
  BatchScoringResponse,
  CoverLetterResponse,
  CritiqueComment,
  CvImportConfirmResponse,
  CvImportResponse,
  CvSection,
  DemoSeedResponse,
  InterviewPrepResponse,
  JobPosting,
  PostingsFetchResponse,
  Profile,
  RenderCvResponse,
  ScoreResponse,
  TaskRun,
  TodayResponse
}