import net.http
import os
import rand
import x.json2 as json

struct Weather {
    lang   string
    result Result
}

struct Result {
    forecast_keypoint string
}

const config = http.FetchConfig{
    user_agent: 'Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:88.0) Gecko/20100101 Firefox/88.0'
}

fn main() {
    dest_lang := if os.args.len > 1 { os.args[1] } else { 'en' }
    rnd := rand.f32()
    url := 'https://api.caiyunapp.com/v2.5/96Ly7wgKGq6FhllM/116.391912,40.010711/weather.jsonp?hourlysteps=120&random=${rnd}'

    resp := http.fetch(http.FetchConfig{ ...config, url: url }) or {
        println('failed to fetch data from the server')
        return
    }

    weather := json.decode[Weather](resp.body) or {
        println('failed to decode weather json')
        return
    }

    for ch in ['未来两小时天气', weather.result.forecast_keypoint] {
        println('${weather.lang:8}: ${ch}')
        t := translate(ch, weather.lang, dest_lang) or {
            println('failed to translate ${ch}: ${err}')
            continue
        }
        println('${dest_lang:8}: ${t}')
    }
}

// translate fetch google to print translate text `q` in languate `sl` into language `tl`.
// A translation typical response json is like: `[[["Weather in the next two hours",
// "未来两小时天气",null,null,3,null,null,[[null,"offline"]],
// [[["61549914d65604307a34fd1855292577","offline_launch_doc.md"],null,null,null,null,
// [[[6,8,0]]]]]]],null,"zh-CN",null,null,null,null,[]]`
// where translated text is located at position `json_resp[0][0][0]`.
fn translate(q string, sl string, tl string) !string {
    url := 'https://translate.googleapis.com/translate_a/single?client=gtx&sl=${sl}&tl=${tl}&dt=t&q=${q}'

    resp := http.fetch(http.FetchConfig{ ...config, url: url })!

    json_resp := json.decode[json.Any](resp.body)!

    a := json_resp.as_array()
    if a.len > 0 {
        a0 := a[0].as_array()
        if a0.len > 0 {
            a00 := a0[0].as_array()
            if a00.len > 0 {
                return a00[0].str()
            }
        }
    }
    return error('invalid translation response')
}