/*
 * api.js
 * Copyright (C) 2024 veypi <i@veypi.com>
 *
 * Distributed under terms of the MIT license.
 */

class API {
  prefix = ''
  fetch = window.fetch
  constructor(prefix, fetch) {
    if (fetch) {
      this.fetch = fetch
    }
    if (typeof prefix === 'string') {
      this.prefix = prefix
    }
    if (!this.prefix.endsWith('/')) {
      this.prefix += '/'
    }
  }
  wrapFetch(fetch) {
    this.fetch = fetch
  }
  wrapUrl(url) {
    if (url.startsWith('http')) {
      return url
    } else if (url.startsWith('/')) {
      return this.prefix + url.slice(1)
    } else {
      return this.prefix + url
    }
  }
  async Fetch(url, method, opts, body) {
    url = this.wrapUrl(url)
    if (!opts) {
      opts = {}
    }
    if (!opts.headers) {
      opts.headers = {}
    }
    opts.method = method
    opts.body = JSON.stringify(body)
    if (!opts.headers['Content-Type']) {
      opts.headers['Content-Type'] = 'application/json'
    }
    if (opts.query && Object.keys(opts.query).length && url.indexOf('?') === -1) {
      url += '?' + new URLSearchParams(opts.query).toString()
    }
    return this.fetch.bind(window)(url, opts).then((response) => {
      if (!response.ok) {
        throw response
      }
      let contentType = response.headers.get('content-type')
      if (contentType && contentType.includes('application/json')) {
        return response.json()
      }
      return response.text()
    }).then(data => {
      if (typeof data === 'string') {
        return data
      }
      if (data.code === 0) {
        return data.data
      } else if (data.code >= 0) {
        throw new Error(JSON.stringify(data))
      } else {
        return data
      }
    })
  }

  async Get(url, opts) {
    return this.Fetch(url, 'GET', opts)
  }

  async Post(url, data, opts) {
    return this.Fetch(url, 'POST', opts, data)
  }

  async Put(url, data, opts) {
    return this.Fetch(url, 'PUT', opts, data)
  }

  async Delete(url, opts) {
    return this.Fetch(url, 'DELETE', opts)
  }

  async Patch(url, data, opts) {
    return this.Fetch(url, 'PATCH', opts, data)
  }

  async SSE(url, opts, cb) {
    url = this.wrapUrl(url)
    let response = await this.fetch.bind(window)(url, opts)
    const reader = response.body.getReader();
    const decoder = new TextDecoder('utf-8');
    let count = 0
    let partialLine = ''
    try {
      while (true) {
        const { done, value } = await reader.read();
        if (done) break; // 结束时退出循环
        // 将Uint8Array转换为字符串
        const chunk = decoder.decode(value, { stream: true });
        // 处理可能跨多个块的消息
        const lines = (partialLine + chunk).split('\n');
        partialLine = lines.pop(); // 最后一行可能是未完成的消息
        for (const line of lines) {
          cb(line, count++)
        }
      }
      // 处理最后一个不完整的行
      if (partialLine) {
        cb(partialLine, count++)
      }
    } catch (error) {
      console.error(error);
    } finally {
      reader.releaseLock();
      cb('', -1)
    }
  }
  New(prefix) {
    return new API(prefix, this.fetch)
  }
}

export default new API()