bogem/vnehm

// Copyright 2016 Albert Nigmatzianov. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package client

import (
    "errors"
    "fmt"
    "net/url"

    "github.com/bogem/vnehm/ui"
    "github.com/valyala/fasthttp"
)

const apiURL = "https://api.vk.com/method"

var (
    ErrForbidden = errors.New("403 - Forbidden")
    ErrNotFound  = errors.New("404 - Not Found")
)

func getTracks(params url.Values) ([]byte, error) {
    uri := formTracksURI(params)
    return get(uri)
}

func formTracksURI(params url.Values) string {
    return apiURL + "/audio.get?" + params.Encode()
}

func search(params url.Values) ([]byte, error) {
    uri := formSearchURI(params)
    return get(uri)
}

func formSearchURI(params url.Values) string {
    return apiURL + "/audio.search?" + params.Encode()
}

func wallAudios(params url.Values) ([]byte, error) {
    uri := formWallAudiosURI(params)
    return get(uri)
}

func formWallAudiosURI(params url.Values) string {
    return apiURL + "/wall.getById?" + params.Encode()
}

func get(uri string) ([]byte, error) {
    statusCode, body, err := fasthttp.Get(nil, uri)
    if err != nil {
        return nil, err
    }
    if err := handleStatusCode(statusCode); err != nil {
        return nil, err
    }
    return body, nil
}

func handleStatusCode(statusCode int) error {
    switch {
    case statusCode == 403:
        return ErrForbidden
    case statusCode == 404:
        return ErrNotFound
    case statusCode >= 300 && statusCode < 500:
        return fmt.Errorf("invalid response from VK: %v", statusCode)
    case statusCode >= 500:
        ui.Term("there is a problem by VK. Please wait a while", nil)
    }
    return nil
}