const BASE = '/api'

let _credentials = null // { user, pass }

export function setCredentials(user, pass) {
  _credentials = { user, pass }
}

export function clearCredentials() {
  _credentials = null
}

async function request(method, path, body, isFormData = false) {
  const opts = { method, headers: {} }

  if (_credentials) {
    opts.headers['Authorization'] = `Basic ${btoa(`${_credentials.user}:${_credentials.pass}`)}`
  }

  if (body) {
    if (isFormData) {
      opts.body = body
    } else {
      opts.headers['Content-Type'] = 'application/json'
      opts.body = JSON.stringify(body)
    }
  }

  const res = await fetch(BASE + path, opts)

  if (res.status === 401) {
    clearCredentials()
    const err = new Error('Unauthorized')
    err.status = 401
    throw err
  }

  const data = await res.json()
  if (!res.ok) throw new Error(data.error || 'Request failed')
  return data
}

export const api = {
  // Sources
  getSources: () => request('GET', '/sources'),
  getSource: (name) => request('GET', `/sources/${name}`),
  createSource: (body) => request('POST', '/sources', body),
  updateSource: (name, body) => request('PUT', `/sources/${name}`, body),
  deleteSource: (name) => request('DELETE', `/sources/${name}`),
  suggestSource: (file) => {
    const fd = new FormData()
    fd.append('file', file)
    return request('POST', '/sources/suggest', fd, true)
  },
  getImportLog: (name) => request('GET', `/sources/${name}/import-log`),
  getStats: (name) => request('GET', `/sources/${name}/stats`),
  importCSV: (name, file) => {
    const fd = new FormData()
    fd.append('file', file)
    return request('POST', `/sources/${name}/import`, fd, true)
  },
  transform: (name) => request('POST', `/sources/${name}/transform`),
  reprocess: (name) => request('POST', `/sources/${name}/reprocess`),
  generateView: (name) => request('POST', `/sources/${name}/view`),
  getFields: (name) => request('GET', `/sources/${name}/fields`),
  getViewData: (name, limit = 100, offset = 0) => request('GET', `/sources/${name}/view-data?limit=${limit}&offset=${offset}`),

  // Rules
  getRules: (source) => request('GET', `/rules/source/${source}`),
  createRule: (body) => request('POST', '/rules', body),
  updateRule: (id, body) => request('PUT', `/rules/${id}`, body),
  deleteRule: (id) => request('DELETE', `/rules/${id}`),
  testRule: (id, limit = 20) => request('GET', `/rules/${id}/test?limit=${limit}`),
  previewRule: (source, field, pattern, flags, function_type = 'extract', replace_value = '', limit = 20) =>
    request('GET', `/rules/preview?source=${encodeURIComponent(source)}&field=${encodeURIComponent(field)}&pattern=${encodeURIComponent(pattern)}&flags=${encodeURIComponent(flags || '')}&function_type=${function_type}&replace_value=${encodeURIComponent(replace_value)}&limit=${limit}`),

  // Mappings
  getMappings: (source, rule) => request('GET', `/mappings/source/${source}${rule ? `?rule_name=${rule}` : ''}`),
  getMappingCounts: (source, rule) => request('GET', `/mappings/source/${source}/counts${rule ? `?rule_name=${rule}` : ''}`),
  getUnmapped: (source, rule) => request('GET', `/mappings/source/${source}/unmapped${rule ? `?rule_name=${rule}` : ''}`),
  getAllValues: (source, rule) => request('GET', `/mappings/source/${source}/all-values${rule ? `?rule_name=${rule}` : ''}`),
  exportMappingsUrl: (source, rule) => `${BASE}/mappings/source/${source}/export.tsv${rule ? `?rule_name=${rule}` : ''}`,
  importMappingsCSV: (source, file) => {
    const fd = new FormData()
    fd.append('file', file)
    return request('POST', `/mappings/source/${source}/import-csv`, fd, true)
  },
  createMapping: (body) => request('POST', '/mappings', body),
  bulkMappings: (mappings) => request('POST', '/mappings/bulk', { mappings }),
  updateMapping: (id, body) => request('PUT', `/mappings/${id}`, body),
  deleteMapping: (id) => request('DELETE', `/mappings/${id}`),

  // Records
  getRecords: (source, limit = 100, offset = 0) =>
    request('GET', `/records/source/${source}?limit=${limit}&offset=${offset}`),
}