// ---------------------------------------------------------------------------
// Client-side API helpers for upload operations
// ---------------------------------------------------------------------------

import type { FolderEntry } from './client-types'
import type { FileDiff } from './types'

export interface CheckResult {
  exists: boolean
  diffs: FileDiff[]
}

export interface StageResult {
  stagingId: string
  folderName: string
  filesCount: number
}

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === 'object' && value !== null
}

function getApiError(data: unknown, fallback: string) {
  return isRecord(data) && typeof data.error === 'string' ? data.error : fallback
}

function isFileDiff(value: unknown): value is FileDiff {
  return isRecord(value)
    && typeof value.name === 'string'
    && (value.status === 'new' || value.status === 'changed' || value.status === 'deleted')
}

// ---------------------------------------------------------------------------
// Shared FormData builder
// ---------------------------------------------------------------------------

function buildUploadFormData(
  folder: FolderEntry,
  extra?: Record<string, string>,
): FormData {
  const formData = new FormData()
  formData.append('folderName', folder.folderName)

  if (extra) {
    for (const [key, value] of Object.entries(extra)) {
      formData.append(key, value)
    }
  }

  formData.append('files', folder.modelFile)
  formData.append('fileTypes', 'model')
  formData.append('textureNames', '')

  for (const tex of folder.textures) {
    formData.append('files', tex.file)
    formData.append('fileTypes', 'texture')
    formData.append('textureNames', tex.name)
  }

  return formData
}

// ---------------------------------------------------------------------------
// Check folder diffs against remote (GitHub)
// ---------------------------------------------------------------------------

/**
 * Check whether a folder already exists on the remote repo and compute diffs.
 * Throws on auth/network errors so callers can surface them to the user.
 */
export async function checkFolderDiffs(
  stagingId: string,
  secret: string,
  signal?: AbortSignal,
): Promise<CheckResult> {
  const res = await fetch('/api/upload/check', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-upload-secret': secret.trim(),
    },
    body: JSON.stringify({ stagingId }),
    signal,
  })

  const data: unknown = await res.json()

  // Surface auth/server errors to the caller
  if (!res.ok) {
    throw new Error(getApiError(data, `Erreur serveur (${res.status})`))
  }

  if (!isRecord(data) || data.success !== true || data.exists !== true) {
    return { exists: false, diffs: [] }
  }

  const diffs = Array.isArray(data.diffs) ? data.diffs.filter(isFileDiff) : []

  return { exists: true, diffs }
}

export async function stageUpload(
  folder: FolderEntry,
  secret: string,
  signal?: AbortSignal,
): Promise<StageResult> {
  const formData = buildUploadFormData(folder)
  const res = await fetch('/api/upload/stage', {
    method: 'POST',
    headers: { 'x-upload-secret': secret.trim() },
    body: formData,
    signal,
  })

  const data: unknown = await res.json()

  if (!res.ok || !isRecord(data) || data.success !== true) {
    throw new Error(getApiError(data, `Erreur serveur (${res.status})`))
  }

  if (typeof data.stagingId !== 'string' || typeof data.folderName !== 'string' || typeof data.filesCount !== 'number') {
    throw new Error('Reponse serveur invalide')
  }

  return {
    stagingId: data.stagingId,
    folderName: data.folderName,
    filesCount: data.filesCount,
  }
}

// ---------------------------------------------------------------------------
// Upload original files to Nextcloud Drive
// ---------------------------------------------------------------------------

/** Upload original files to Nextcloud Drive. */
export async function uploadDrive(
  stagingId: string,
  secret: string,
  action: 'new' | 'replace',
  signal?: AbortSignal,
): Promise<{ success: boolean; error?: string }> {
  try {
    const res = await fetch('/api/upload/drive', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-upload-secret': secret.trim(),
      },
      body: JSON.stringify({ stagingId, action }),
      signal,
    })
    const data: unknown = await res.json()
    if (!res.ok || !isRecord(data) || data.success !== true) {
      return { success: false, error: getApiError(data, `Erreur serveur (${res.status})`) }
    }
    return { success: true }
  } catch (err) {
    if (err instanceof DOMException && err.name === 'AbortError') {
      return { success: false, error: 'Upload annule' }
    }
    return { success: false, error: 'Erreur reseau (Drive)' }
  }
}

// ---------------------------------------------------------------------------
// Upload files to GitHub
// ---------------------------------------------------------------------------

/** Upload files to GitHub. */
export async function uploadGit(
  stagingId: string,
  secret: string,
  onProgress: (pct: number) => void,
  signal?: AbortSignal,
): Promise<{ success: boolean; filename?: string; error?: string }> {
  onProgress(10)

  try {
    const res = await fetch('/api/upload/git', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-upload-secret': secret.trim(),
      },
      body: JSON.stringify({ stagingId }),
      signal,
    })

    onProgress(80)
    const data: unknown = await res.json()

    if (!res.ok || !isRecord(data) || data.success !== true) {
      return { success: false, error: getApiError(data, `Erreur serveur (${res.status})`) }
    }

    onProgress(100)
    return { success: true, filename: typeof data.folderName === 'string' ? data.folderName : undefined }
  } catch (err) {
    if (err instanceof DOMException && err.name === 'AbortError') {
      return { success: false, error: 'Upload annule' }
    }
    return { success: false, error: 'Erreur reseau' }
  }
}