const API_BASE = import.meta.env.VITE_API_BASE || 'http://localhost:8000'
const AUTH_TOKEN_STORAGE_KEY = 'mesa_auth_token'

let AUTH_TOKEN = ''
if (typeof window !== 'undefined') {
  AUTH_TOKEN = window.localStorage.getItem(AUTH_TOKEN_STORAGE_KEY) || ''
}

export function setAuthToken(token) {
  const value = String(token || '').trim()
  AUTH_TOKEN = value
  if (typeof window === 'undefined') return
  if (value) {
    window.localStorage.setItem(AUTH_TOKEN_STORAGE_KEY, value)
  } else {
    window.localStorage.removeItem(AUTH_TOKEN_STORAGE_KEY)
  }
}

export function getAuthToken() {
  return AUTH_TOKEN
}

function authHeaders(extraHeaders = {}) {
  const headers = { ...extraHeaders }
  if (AUTH_TOKEN) headers['X-Auth-Token'] = AUTH_TOKEN
  return headers
}

function emitAuthRequired(detail = 'Login obrigatorio') {
  if (typeof window === 'undefined') return
  const event = new CustomEvent('mesa:auth-required', { detail: { message: detail } })
  window.dispatchEvent(event)
}

function describeFetchFailure(cause) {
  const name = String(cause?.name || '').trim()
  const message = String(cause?.message || '').trim()

  if (name === 'AbortError') {
    return 'a requisicao foi interrompida antes de concluir'
  }
  if (typeof navigator !== 'undefined' && navigator.onLine === false) {
    return 'sem conexao com a internet'
  }
  if (/failed to fetch|networkerror|load failed/i.test(message)) {
    return 'conexao interrompida durante a transferencia ou bloqueio de rede/CORS/proxy'
  }
  return message || 'falha de rede nao identificada'
}

function buildFetchError(path, stage, cause, status = null) {
  const endpoint = String(path || '').trim() || '(endpoint desconhecido)'
  const reason = describeFetchFailure(cause)
  const statusNumber = Number(status)
  const statusLabel = Number.isFinite(statusNumber) ? ` (HTTP ${statusNumber})` : ''
  const action = stage === 'body'
    ? `Falha ao receber dados de ${endpoint}${statusLabel}`
    : `Falha ao conectar com ${endpoint}`
  const error = new Error(`${action}. Motivo: ${reason}.`)
  error.path = endpoint
  error.stage = stage
  error.reason = reason
  if (Number.isFinite(statusNumber)) {
    error.status = statusNumber
  }
  error.cause = cause
  return error
}

async function fetchWithDiagnostics(path, options = {}) {
  try {
    return await fetch(`${API_BASE}${path}`, options)
  } catch (cause) {
    throw buildFetchError(path, 'request', cause)
  }
}

async function responseBlobWithDiagnostics(response, path = '') {
  try {
    return await response.blob()
  } catch (cause) {
    throw buildFetchError(path, 'body', cause, response?.status)
  }
}

async function handleResponse(response, path = '') {
  if (!response.ok) {
    let detail = 'Erro inesperado'
    try {
      const data = await response.json()
      detail = data.detail || detail
    } catch {
      detail = response.statusText || detail
    }
    const detailMessage = typeof detail === 'string'
      ? detail
      : String(detail?.message || response.statusText || 'Erro inesperado')

    if (response.status === 401 && path !== '/api/auth/login') {
      setAuthToken('')
      emitAuthRequired(detailMessage)
    }
    const error = new Error(detailMessage)
    error.status = response.status
    error.path = path
    error.detail = detail
    throw error
  }
  return response
}

async function postJson(path, body) {
  const response = await fetchWithDiagnostics(path, {
    method: 'POST',
    headers: authHeaders({ 'Content-Type': 'application/json' }),
    body: JSON.stringify(body),
  })
  await handleResponse(response, path)
  return response.json()
}

async function postForm(path, formData) {
  const response = await fetchWithDiagnostics(path, {
    method: 'POST',
    headers: authHeaders(),
    body: formData,
  })
  await handleResponse(response, path)
  return response.json()
}

async function getJson(path) {
  const response = await fetchWithDiagnostics(path, { headers: authHeaders() })
  await handleResponse(response, path)
  return response.json()
}

async function getBlob(path) {
  const response = await fetchWithDiagnostics(path, { headers: authHeaders() })
  await handleResponse(response, path)
  return responseBlobWithDiagnostics(response, path)
}

export function downloadBlob(blob, fileName) {
  const url = URL.createObjectURL(blob)
  const a = document.createElement('a')
  a.href = url
  a.download = fileName
  document.body.appendChild(a)
  a.click()
  a.remove()
  URL.revokeObjectURL(url)
}

export const api = {
  authLogin: (usuario, matricula) => postJson('/api/auth/login', { usuario, matricula }),
  authMe: () => getJson('/api/auth/me'),
  authLogout: () => postJson('/api/auth/logout', {}),

  createSession: () => postJson('/api/sessions', {}),

  pesquisaAdminConfig: () => getJson('/api/pesquisa/admin-config'),
  pesquisaAdminConfigSalvar: (campos = {}) => postJson('/api/pesquisa/admin-config', { campos }),

  pesquisarModelos(filtros = {}) {
    const params = new URLSearchParams()
    Object.entries(filtros).forEach(([key, value]) => {
      if (value === null || value === undefined) return
      const text = String(value).trim()
      if (!text) return
      params.append(key, text)
    })
    const query = params.toString()
    return getJson(query ? `/api/pesquisa/modelos?${query}` : '/api/pesquisa/modelos')
  },
  pesquisarMapaModelos(modelosIds = []) {
    return postJson('/api/pesquisa/mapa-modelos', { modelos_ids: modelosIds })
  },

  uploadElaboracaoFile(sessionId, file) {
    const form = new FormData()
    form.append('session_id', sessionId)
    form.append('file', file)
    return postForm('/api/elaboracao/upload', form)
  },
  elaboracaoRepositorioModelos: () => getJson('/api/elaboracao/repositorio-modelos'),
  elaboracaoRepositorioCarregar: (sessionId, modeloId) => postJson('/api/elaboracao/repositorio-carregar', { session_id: sessionId, modelo_id: modeloId }),

  confirmSheet: (sessionId, sheetName) => postJson('/api/elaboracao/confirm-sheet', { session_id: sessionId, sheet_name: sheetName }),
  mapCoords: (sessionId, colLat, colLon) => postJson('/api/elaboracao/map-coords', { session_id: sessionId, col_lat: colLat, col_lon: colLon }),
  geocodificar: (sessionId, colCdlog, colNum, auto200) => postJson('/api/elaboracao/geocodificar', { session_id: sessionId, col_cdlog: colCdlog, col_num: colNum, auto_200: auto200 }),
  geocodificarCorrecoes: (sessionId, correcoes, auto200) => postJson('/api/elaboracao/geocodificar-correcoes', { session_id: sessionId, correcoes, auto_200: auto200 }),
  geocodificarReiniciar: (sessionId) => postJson('/api/elaboracao/geocodificar-reiniciar', { session_id: sessionId }),
  geocodificarExcluirCoords: (sessionId) => postJson('/api/elaboracao/geocodificar-excluir-coords', { session_id: sessionId }),

  applySelection(payload) {
    return postJson('/api/elaboracao/apply-selection', payload)
  },
  classifyElaboracaoX: (sessionId, colunasX) => postJson('/api/elaboracao/classify-x', { session_id: sessionId, colunas_x: colunasX }),

  searchTransformations: (sessionId, grauCoef, grauF, transformacoesFixas = {}, transformacaoYFixa = 'Livre') => postJson('/api/elaboracao/search-transformations', {
    session_id: sessionId,
    grau_min_coef: grauCoef,
    grau_min_f: grauF,
    transformacoes_fixas: transformacoesFixas,
    transformacao_y_fixa: transformacaoYFixa,
  }),

  adoptSuggestion: (sessionId, indice) => postJson('/api/elaboracao/adopt-suggestion', { session_id: sessionId, indice }),

  fitModel(payload) {
    return postJson('/api/elaboracao/fit-model', payload)
  },

  updateModelDispersao: (sessionId, payload) => postJson('/api/elaboracao/model-dispersao', {
    session_id: sessionId,
    ...(payload || {}),
  }),
  getDispersaoInterativo: (sessionId, alvo) => postJson('/api/elaboracao/dispersao-interativo', {
    session_id: sessionId,
    alvo,
  }),
  getDiagnosticoInterativo: (sessionId, grafico) => postJson('/api/elaboracao/diagnostico-interativo', {
    session_id: sessionId,
    grafico,
  }),
  previewTransformElab: (sessionId, transformacaoY, transformacoesX) => postJson('/api/elaboracao/transform-preview', {
    session_id: sessionId,
    transformacao_y: transformacaoY,
    transformacoes_x: transformacoesX,
  }),

  applyOutlierFilters: (sessionId, filtros) => postJson('/api/elaboracao/outliers/apply-filters', { session_id: sessionId, filtros }),
  applyOutlierFiltersRecursive: (sessionId, filtros) => postJson('/api/elaboracao/outliers/apply-filters-recursive', { session_id: sessionId, filtros }),
  restartOutlierIteration: (sessionId, outliersTexto, reincluirTexto, grauCoef, grauF) => postJson('/api/elaboracao/outliers/restart', {
    session_id: sessionId,
    outliers_texto: outliersTexto,
    reincluir_texto: reincluirTexto,
    grau_min_coef: grauCoef,
    grau_min_f: grauF,
  }),
  outlierSummary: (sessionId, outliersTexto, reincluirTexto) => postJson('/api/elaboracao/outliers/summary', {
    session_id: sessionId,
    outliers_texto: outliersTexto,
    reincluir_texto: reincluirTexto,
  }),
  clearOutlierHistory: (sessionId) => postJson('/api/elaboracao/outliers/clear-history', { session_id: sessionId }),

  evaluationFieldsElab: (sessionId) => postJson('/api/elaboracao/evaluation/fields', { session_id: sessionId }),
  evaluationCalculateElab: (sessionId, valoresX, indiceBase) => postJson('/api/elaboracao/evaluation/calculate', {
    session_id: sessionId,
    valores_x: valoresX,
    indice_base: indiceBase,
  }),
  evaluationKnnDetailsElab: (sessionId, valoresX) => postJson('/api/elaboracao/evaluation/knn-details', {
    session_id: sessionId,
    valores_x: valoresX,
  }),
  evaluationClearElab: (sessionId) => postJson('/api/elaboracao/evaluation/clear', { session_id: sessionId }),
  evaluationDeleteElab: (sessionId, indice, indiceBase) => postJson('/api/elaboracao/evaluation/delete', {
    session_id: sessionId,
    indice,
    indice_base: indiceBase,
  }),
  getAvaliadores: () => getJson('/api/elaboracao/avaliadores'),
  evaluationBaseElab: (sessionId, indiceBase) => postJson('/api/elaboracao/evaluation/base', {
    session_id: sessionId,
    indice_base: indiceBase,
  }),
  exportEvaluationElab: async (sessionId) => getBlob(`/api/elaboracao/evaluation/export?session_id=${encodeURIComponent(sessionId)}`),
  exportEquationElab: async (sessionId, mode = 'excel') => getBlob(`/api/elaboracao/equation/export?session_id=${encodeURIComponent(sessionId)}&mode=${encodeURIComponent(String(mode || 'excel'))}`),
  exportModel: async (sessionId, nomeArquivo, elaborador) => {
    const path = '/api/elaboracao/export-model'
    const response = await fetchWithDiagnostics(path, {
      method: 'POST',
      headers: authHeaders({ 'Content-Type': 'application/json' }),
      body: JSON.stringify({ session_id: sessionId, nome_arquivo: nomeArquivo, elaborador }),
    })
    await handleResponse(response, path)
    return responseBlobWithDiagnostics(response, path)
  },
  exportBase: (sessionId, filtered = true) => getBlob(`/api/elaboracao/export-base?session_id=${encodeURIComponent(sessionId)}&filtered=${String(filtered)}`),
  updateElaboracaoMap: (sessionId, variavelMapa, modoMapa = 'pontos') => postJson('/api/elaboracao/map/update', {
    session_id: sessionId,
    variavel_mapa: variavelMapa,
    modo_mapa: modoMapa,
  }),
  updateElaboracaoResiduosMap: (sessionId, variavelMapa, modoMapa = 'pontos', escalaExtremoAbs = null) => postJson('/api/elaboracao/residuos/map/update', {
    session_id: sessionId,
    variavel_mapa: variavelMapa,
    modo_mapa: modoMapa,
    escala_extremo_abs: escalaExtremoAbs,
  }),
  previewMarketDateColumn: (sessionId, colunaData) => postJson('/api/elaboracao/market-date/preview', { session_id: sessionId, coluna_data: colunaData }),
  applyMarketDateColumn: (sessionId, colunaData) => postJson('/api/elaboracao/market-date/apply', { session_id: sessionId, coluna_data: colunaData }),
  getContext: (sessionId) => getJson(`/api/elaboracao/context?session_id=${encodeURIComponent(sessionId)}`),

  uploadVisualizacaoFile(sessionId, file) {
    const form = new FormData()
    form.append('session_id', sessionId)
    form.append('file', file)
    return postForm('/api/visualizacao/upload', form)
  },
  visualizacaoRepositorioModelos: () => getJson('/api/visualizacao/repositorio-modelos'),
  visualizacaoRepositorioCarregar: (sessionId, modeloId) => postJson('/api/visualizacao/repositorio-carregar', { session_id: sessionId, modelo_id: modeloId }),
  exibirVisualizacao: (sessionId) => postJson('/api/visualizacao/exibir', { session_id: sessionId }),
  evaluationContextViz: (sessionId) => postJson('/api/visualizacao/evaluation/context', { session_id: sessionId }),
  updateVisualizacaoMap: (sessionId, variavelMapa) => postJson('/api/visualizacao/map/update', { session_id: sessionId, variavel_mapa: variavelMapa }),
  evaluationFieldsViz: (sessionId) => postJson('/api/visualizacao/evaluation/fields', { session_id: sessionId }),
  evaluationCalculateViz: (sessionId, valoresX, indiceBase) => postJson('/api/visualizacao/evaluation/calculate', {
    session_id: sessionId,
    valores_x: valoresX,
    indice_base: indiceBase,
  }),
  evaluationKnnDetailsViz: (sessionId, valoresX) => postJson('/api/visualizacao/evaluation/knn-details', {
    session_id: sessionId,
    valores_x: valoresX,
  }),
  evaluationClearViz: (sessionId) => postJson('/api/visualizacao/evaluation/clear', { session_id: sessionId }),
  evaluationDeleteViz: (sessionId, indice, indiceBase) => postJson('/api/visualizacao/evaluation/delete', {
    session_id: sessionId,
    indice,
    indice_base: indiceBase,
  }),
  evaluationBaseViz: (sessionId, indiceBase) => postJson('/api/visualizacao/evaluation/base', {
    session_id: sessionId,
    indice_base: indiceBase,
  }),
  exportEvaluationViz: (sessionId) => getBlob(`/api/visualizacao/evaluation/export?session_id=${encodeURIComponent(sessionId)}`),
  exportEquationViz: (sessionId, mode = 'excel') => getBlob(`/api/visualizacao/equation/export?session_id=${encodeURIComponent(sessionId)}&mode=${encodeURIComponent(String(mode || 'excel'))}`),
  clearVisualizacao: (sessionId) => postJson('/api/visualizacao/clear', { session_id: sessionId }),

  repositorioListar: () => getJson('/api/repositorio/modelos'),
  repositorioUpload(files = [], { confirmarSubstituicao = false } = {}) {
    const form = new FormData()
    files.forEach((file) => {
      form.append('files', file)
    })
    form.append('confirmar_substituicao', confirmarSubstituicao ? 'true' : 'false')
    return postForm('/api/repositorio/upload', form)
  },
  repositorioDelete: (modelosIds = []) => postJson('/api/repositorio/delete', { modelos_ids: modelosIds }),

  logsStatus: () => getJson('/api/logs/status'),
  logsEvents({ scope = '', usuario = '', limit = 200 } = {}) {
    const params = new URLSearchParams()
    const scopeText = String(scope || '').trim()
    const usuarioText = String(usuario || '').trim()
    const limitNumber = Number(limit)
    if (scopeText) params.set('scope', scopeText)
    if (usuarioText) params.set('usuario', usuarioText)
    if (Number.isFinite(limitNumber) && limitNumber > 0) params.set('limit', String(Math.floor(limitNumber)))
    const query = params.toString()
    return getJson(query ? `/api/logs/events?${query}` : '/api/logs/events')
  },
}