const { request } = require('./wx-promisify')

function buildApiUrl() {
  const app = getApp()
  const apiUrl = app && app.globalData ? app.globalData.svgRenderApiUrl : ''
  if (!apiUrl) {
    throw new Error('未配置渲染 API 地址')
  }
  return apiUrl
}

function normalizeResult(data) {
  if (!data || typeof data !== 'object') {
    throw new Error('渲染服务返回格式无效')
  }

  if (typeof data.svg !== 'string' || !data.svg.trim()) {
    throw new Error('渲染服务未返回有效 SVG')
  }

  return {
    svg: data.svg,
    width: Number(data.width) || 0,
    height: Number(data.height) || 0,
    fontName: data.fontName || 'Unknown',
    fontId: data.fontId || '',
  }
}

async function renderSvgByApi(payload) {
  const app = getApp()
  const timeout = app && app.globalData && app.globalData.apiTimeoutMs
    ? Number(app.globalData.apiTimeoutMs)
    : 30000

  const response = await request({
    url: buildApiUrl(),
    method: 'POST',
    timeout,
    header: {
      'content-type': 'application/json',
    },
    data: {
      fontId: payload.fontId,
      text: payload.text,
      fontSize: payload.fontSize,
      fillColor: payload.fillColor,
      letterSpacing: payload.letterSpacing,
      maxCharsPerLine: payload.maxCharsPerLine,
    },
  })

  if (!response || response.statusCode < 200 || response.statusCode >= 300) {
    throw new Error(`渲染服务请求失败，状态码: ${response && response.statusCode}`)
  }

  const body = response.data || {}
  if (!body.ok) {
    throw new Error(body.error || '渲染服务返回错误')
  }

  return normalizeResult(body.data)
}

module.exports = {
  renderSvgByApi,
}