/** ------------------------------------------------------------
 * File          : chsrc.h
 * License       : GPLv3
 * Authors       : Aoran Zeng <ccmywish@qq.com>
 * Created on    : <2023-08-29>
 * Last modified : <2024-06-07>
 *
 * chsrc:
 *
 *   chsrc.c 头文件
 * ------------------------------------------------------------*/

#include "xy.h"
#include "source.h"


#define App_Prefix "chsrc: "
#define chsrc_success(str) xy_success(xy_2strjoin(App_Prefix, (str)))
#define chsrc_info(str)    xy_info(xy_2strjoin(App_Prefix,  (str)))
#define chsrc_warn(str)    xy_warn(xy_2strjoin(App_Prefix,  (str)))
#define chsrc_error(str)   xy_error(xy_2strjoin(App_Prefix, (str)))


bool Cli_Option_IPv6 = false;
bool Cli_Option_Locally = false;
bool Cli_Option_InEnglish = false;

/**
 * 检测二进制程序是否存在
 *
 * @param  check_cmd  检测 `prog_name` 是否存在的一段命令，一般来说，填 `prog_name` 本身即可，
 *                    但是某些情况下，需要使用其他命令绕过一些特殊情况，比如 python 这个命令在Windows上
 *                    会自动打开 Microsoft Store，需避免
 *
 * @param  prog_name   要检测的二进制程序名
 */
bool
query_program_exist (char *check_cmd, char *prog_name)
{
  char *which = check_cmd;

  int ret = system(which);

  // char buf[32] = {0}; sprintf(buf, "错误码: %d", ret);

  if (0 != ret)
    {
      // xy_warn (xy_strjoin(4, "× 命令 ", progname, " 不存在，", buf));
      puts (xy_strjoin (4, xy_str_to_red ("x "), "命令 ", xy_str_to_red (prog_name), " 不存在"));
      return false;
    }
  else
    {
      puts (xy_strjoin (4, xy_str_to_green ("√ "), "命令 ", xy_str_to_green (prog_name), " 存在"));
      return true;
    }
}


/**
 * 用于 _setsrc 函数，检测用户输入的镜像站code，是否存在于该target可用源中
 *
 * @param  target  目标名
 * @param  input   如果用户输入 default 或者 def，则选择第一个源
 */
#define find_mirror(s, input) query_mirror_exist(s##_sources, s##_sources_n, (char*)#s+3, input)
int
query_mirror_exist (SourceInfo *sources, size_t size, char *target, char *input)
{
  if (0==size || 1==size)
    {
      xy_error (xy_strjoin (3, "当前 ", target, " 无任何可用源，请联系维护者"));
      exit (1);
    }

  if (2==size)
    {
      xy_success (xy_strjoin (4, sources[1].mirror->name, " 是 ", target, " 目前唯一可用镜像站，感谢他们的慷慨支持"));
    }

  if (xy_streql ("reset", input))
    {
      puts ("将重置为上游默认源");
      return 0; // 返回第1个，因为第1个是上游默认源
    }

  if (xy_streql ("first", input))
    {
      puts ("使用维护团队测速第一的源");
      return 1; // 返回第2个，因为第1个是上游默认源
    }

  int idx = 0;
  SourceInfo source = sources[0];

  bool exist = false;
  for (int i=0; i<size; i++)
    {
      source = sources[i];
      if (xy_streql (source.mirror->code, input))
        {
          idx = i;
          exist = true;
          break;
        }
    }
  if (!exist)
    {
      xy_error (xy_strjoin (3, "镜像站 ", input, " 不存在"));
      xy_error (xy_2strjoin ("查看可使用源，请使用 chsrc list ", target));
      exit (1);
    }
  return idx;
}


/**
 * 该函数来自 oh-my-mirrorz.py，由 @ccmywish 翻译为C语言，但功劳和版权属于原作者
 */
char *
to_human_readable_speed (double speed)
{
  char *scale[] = {"Byte/s", "KByte/s", "MByte/s", "GByte/s", "TByte/s"};
  int i = 0;
  while (speed > 1024.0)
  {
    i += 1;
    speed /= 1024.0;
  }
  char *buf = xy_malloc0 (64);
  sprintf (buf, "%.2f %s", speed, scale[i]);

  char *new = NULL;
  if (i <= 1 ) new = xy_str_to_red (buf);
  else
    {
      if (i == 2 && speed < 2.00) new = xy_str_to_yellow (buf);
      else new = xy_str_to_green (buf);
    }
  return new;
}


/**
 * 测速代码参考自 https://github.com/mirrorz-org/oh-my-mirrorz/blob/master/oh-my-mirrorz.py
 * 功劳和版权属于原作者，由 @ccmywish 修改为C语言，并做了额外调整
 *
 * @return 返回测得的速度，若出错，返回-1
 */
double
test_speed_url (const char *url)
{
  char *time_sec = "6";

  /* 现在我们切换至跳转后的链接来测速，不再使用下述判断
  if (xy_str_start_with(url, "https://registry.npmmirror"))
    {
      // 这里 npmmirror 跳转非常慢，需要1~3秒，所以我们给它留够至少8秒测速时间，否则非常不准
      time_sec = "10";
    }
  */

  char *ipv6 = ""; // 默认不启用

  if (Cli_Option_IPv6==true) {
    ipv6 = "--ipv6";
  }

  // 我们用 —L，因为Ruby China源会跳转到其他地方
  // npmmirror 也会跳转
  char *curl_cmd = xy_strjoin (7, "curl -qsL ", ipv6,
                                  " -o " xy_os_devnull,
                                  " -w \"%{http_code} %{speed_download}\" -m", time_sec ,
                                  " -A chsrc/" Chsrc_Version "  ", url);

  // xy_info (xy_2strjoin ("chsrc: 测速命令 ", curl_cmd));

  char *buf = xy_getcmd (curl_cmd, 0, NULL);
  // 如果尾部有换行，删除
  buf = xy_str_strip (buf);

  // 分隔两部分数据
  char *split = strchr (buf, ' ');
  if (split) *split = '\0';

  // puts(buf); puts(split+1);
  int http_code = atoi (buf);
  double speed  = atof (split+1);
  char *speedstr = to_human_readable_speed (speed);

  if (200!=http_code)
    {
      char* httpcodestr = xy_str_to_yellow (xy_2strjoin ("HTTP码 ", buf));
      puts (xy_strjoin (3, speedstr, " | ",  httpcodestr));
    }
  else
    {
      puts (speedstr);
    }
  return speed;
}


int
get_max_ele_idx_in_dbl_ary (double *array, int size)
{
  double maxval = array[0];
  int maxidx = 0;

  for (int i=1; i<size; i++)
    {
      if (array[i]>maxval)
        {
          maxval = array[i];
          maxidx = i;
        }
    }
  return maxidx;
}

/**
 * 自动测速选择镜像站和源
 */
#define auto_select(s) auto_select_(s##_sources, s##_sources_n, (char*)#s+3)
int
auto_select_ (SourceInfo *sources, size_t size, const char *target)
{
  if (0==size || 1==size)
    {
      xy_error (xy_strjoin (3, "chsrc: 当前 ", target, " 无任何可用源，请联系维护者"));
      exit (1);
    }

  bool onlyone = false;
  if (2==size) onlyone = true;

  double speeds[size];
  double speed = 0.0;
  for (int i=0;i<size;i++)
  {
    SourceInfo src = sources[i];
    const char* url = src.mirror->__bigfile_url;
    if (NULL==url)
      {
        if (xy_streql ("upstream", src.mirror->code))
          {
            continue; // 上游默认源不测速
          }
        else
          {
            chsrc_warn (xy_strjoin (3, "开发者未提供 ",  src.mirror->code, " 镜像站测速链接，跳过该站点"));
            speed = 0;
          }
      }
    else
      {
        printf ("%s", xy_strjoin (3, "测速 ", src.mirror->site , " ... "));
        fflush (stdout);
        speed = test_speed_url (url);
      }
    speeds[i] = speed;
  }
  int fastidx = get_max_ele_idx_in_dbl_ary (speeds, size);

  if (onlyone)
    xy_success (xy_strjoin (4, sources[fastidx].mirror->name, " 是 ", target, " 目前唯一可用镜像站，感谢他们的慷慨支持"));
  else
    puts (xy_2strjoin ("最快镜像站: ", xy_str_to_green (sources[fastidx].mirror->name)));

  return fastidx;
}


#define use_specific_mirror_or_auto_select(input, s) \
  (NULL!=(input)) ? find_mirror(s, input) : auto_select(s)



bool
is_upstream (SourceInfo *source)
{
  return xy_streql (source->mirror->code, "upstream");
}

bool
source_is_null (SourceInfo *source)
{
  return source->url == NULL;
}


/**
 * 用于 _setsrc 函数
 *
 * 1. 告知用户选择了什么源和镜像
 * 2. 对选择的源和镜像站进行一定的校验
 */
void
chsrc_say_selection (SourceInfo *source)
{
  // 由于实现问题，我们把本应该独立出去的默认上游源，也放在了可以换源的数组中，而且放在第一个
  // chsrc 已经规避用户使用未实现的 `chsrc reset`
  // 但是某些用户可能摸索着强行使用 chsrc set target upstream，从而执行起该禁用的功能，
  // 之所以禁用，是因为有的 reset 我们并没有实现，我们在这里阻止这些邪恶的用户
  if (is_upstream (source) && source_is_null (source))
    {
      chsrc_error ("暂未对该软件实现重置");
      exit (2);
    }
  else if (source_is_null (source))
    {
      chsrc_error ("该源URL不存在，请向开发团队提交bug");
      exit (2);
    }
  else
    {
      puts (xy_strjoin (5, "选中镜像站: ", xy_str_to_green (source->mirror->abbr), " (", xy_str_to_green (source->mirror->code), ")"));
    }
}


void
chsrc_say_thanks (SourceInfo *source)
{
  puts ("--------------------------------");
  if (is_upstream (source))
    {
      puts (xy_str_to_purple ("已重置为上游默认源"));
    }
  else
    {
      puts (xy_2strjoin ("换源完成，感谢镜像提供方: ", xy_str_to_purple (source->mirror->name)));
    }
}



void
chsrc_ensure_root ()
{
  char *euid = getenv ("$EUID");
  if (NULL==euid)
    {
      char *buf = xy_getcmd ("id -u", 0, NULL);
      if (0!=atoi(buf)) goto not_root;
      else return;
    }
  else
    {
      if (0!=atoi(euid)) goto not_root;
      else return;
    }
not_root:
  xy_error ("chsrc: 请在命令前使用 sudo 来保证必要的权限");
  exit (1);
}


static void
chsrc_run (const char *cmd)
{
  puts ("~~~~~~~~~~~");
  puts (xy_2strjoin ("运行 ", xy_str_to_blue (cmd)));
  system (cmd);
}

static void
chsrc_check_file (const char *path)
{
  char *cmd = NULL;
  path = xy_uniform_path (path);
  if(xy_on_windows)
    {
      cmd = xy_2strjoin ("type ", path);
    }
  else
    {
      cmd = xy_2strjoin ("cat ", path);
    }
  chsrc_run (cmd);
}

static void
chsrc_ensure_dir (const char *dir)
{
  dir = xy_uniform_path (dir);
  char *mkdir_cmd = NULL;
  if (xy_on_windows)
    {
      mkdir_cmd = "md ";
    }
  else
    {
      mkdir_cmd = "mkdir -p ";
    }
  char *cmd = xy_2strjoin (mkdir_cmd, dir);
  cmd = xy_str_to_quietcmd (cmd);
  chsrc_run (cmd);
}

static void
chsrc_append_to_file (const char *str, const char *file)
{
  file = xy_uniform_path (file);
  char *dir = xy_parent_dir (file);
  chsrc_ensure_dir (dir);

  char *cmd = NULL;
  if (xy_on_windows)
    {
      cmd = xy_strjoin (4, "echo ", str, " >> ", file);
    }
  else
    {
      cmd = xy_strjoin (4, "echo '", str, "' >> ", file);
    }
  chsrc_run (cmd);
}

static void
chsrc_overwrite_file (const char *str, const char *file)
{
  file = xy_uniform_path (file);
  char *dir = xy_parent_dir (file);
  chsrc_ensure_dir (dir);

  char *cmd = NULL;
  if (xy_on_windows)
    {
      cmd = xy_strjoin (4, "echo ", str, " > ", file);
    }
  else
    {
      cmd = xy_strjoin (4, "echo '", str, "' > ", file);
    }
  chsrc_run (cmd);
}

static void
chsrc_backup (const char *path)
{
  char *cmd = NULL;

  if (xy_on_bsd)
    {
      // 似乎BSD的cp并没有 --backup='t' 选项
      cmd = xy_strjoin (5, "cp -f ", path, " ", path, ".bak");
    }
  else if (xy_on_windows)
    {
      // /Y 表示覆盖
      cmd = xy_strjoin (5, "copy /Y ", path, " ", path, ".bak" );
    }
  else
    {
      cmd = xy_strjoin (5, "cp ", path, " ", path, ".bak --backup='t'");
    }

  chsrc_run (cmd);
  chsrc_info (xy_strjoin (3, "备份文件名 ", path, ".bak"));
}



/* Target Info */
typedef struct TargetInfo_t {
  void (*getfn)   (char *option);
  void (*setfn)   (char *option);
  void (*resetfn) (char *option);
  SourceInfo *sources;
  size_t      sources_n;
} TargetInfo;

// 大部分target还不支持reset，所以暂时先默认设置为NULL来过渡
#define def_target(t) TargetInfo t##_target = {t##_getsrc, t##_setsrc, NULL, t##_sources, t##_sources_n}

#define def_target_full(t) TargetInfo t##_target = {t##_getsrc, t##_setsrc, t##_resetsrc, t##_sources, t##_sources_n}

#define def_target_noget(t) TargetInfo t##_target = {NULL, t##_setsrc, NULL, t##_sources, t##_sources_n}