/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/fmt/itoa.h"
#include "libc/macros.h"
#include "net/http/http.h"

static const struct thatispacked HttpReason {
  short code;
  const char *name;
} kHttpReason[] = {
    {100, "Continue"},
    {101, "Switching Protocols"},
    {102, "Processing"},
    {200, "OK"},
    {201, "Created"},
    {202, "Accepted"},
    {203, "Non-authoritative Information"},
    {204, "No Content"},
    {205, "Reset Content"},
    {206, "Partial Content"},
    {207, "Multi-Status"},
    {208, "Already Reported"},
    {226, "IM Used"},
    {300, "Multiple Choices"},
    {301, "Moved Permanently"},
    {302, "Found"},
    {303, "See Other"},
    {304, "Not Modified"},
    {305, "Use Proxy"},
    {307, "Temporary Redirect"},
    {308, "Permanent Redirect"},
    {400, "Bad Request"},
    {401, "Unauthorized"},
    {402, "Payment Required"},
    {403, "Forbidden"},
    {404, "Not Found"},
    {405, "Method Not Allowed"},
    {406, "Not Acceptable"},
    {407, "Proxy Authentication Required"},
    {408, "Request Timeout"},
    {409, "Conflict"},
    {410, "Gone"},
    {411, "Length Required"},
    {412, "Precondition Failed"},
    {413, "Payload Too Large"},
    {414, "Request-URI Too Long"},
    {415, "Unsupported Media Type"},
    {416, "Requested Range Not Satisfiable"},
    {417, "Expectation Failed"},
    {418, "I'm a teapot"},
    {421, "Misdirected Request"},
    {422, "Unprocessable Entity"},
    {423, "Locked"},
    {424, "Failed Dependency"},
    {426, "Upgrade Required"},
    {428, "Precondition Required"},
    {429, "Too Many Requests"},
    {431, "Request Header Fields Too Large"},
    {444, "Connection Closed Without Response"},
    {451, "Unavailable For Legal Reasons"},
    {499, "Client Closed Request"},
    {500, "Internal Server Error"},
    {501, "Not Implemented"},
    {502, "Bad Gateway"},
    {503, "Service Unavailable"},
    {504, "Gateway Timeout"},
    {505, "HTTP Version Not Supported"},
    {506, "Variant Also Negotiates"},
    {507, "Insufficient Storage"},
    {508, "Loop Detected"},
    {510, "Not Extended"},
    {511, "Network Authentication Required"},
    {599, "Network Connect Timeout Error"},
};

/**
 * Returns string describing HTTP reason phrase.
 *
 * @see https://tools.ietf.org/html/rfc2616
 * @see https://tools.ietf.org/html/rfc6585
 */
const char *GetHttpReason(int code) {
  int m, l, r;
  l = 0;
  r = ARRAYLEN(kHttpReason) - 1;
  while (l <= r) {
    m = (l & r) + ((l ^ r) >> 1);  // floor((a+b)/2)
    if (kHttpReason[m].code < code) {
      l = m + 1;
    } else if (kHttpReason[m].code > code) {
      r = m - 1;
    } else {
      return kHttpReason[m].name;
    }
  }
  return "";
}