<?php
/*************************************************************
# 076 License

Copyright (c) テクニカル諏訪子

Permission is hereby granted to any person obtaining a copy of the software
Little Beast (the "Software") to use, modify, merge, copy, publish, distribute,
sublicense, and/or sell copies of the Software, subject to the following conditions:

    1. **Origin Attribution**:
       - You must not misrepresent the origin of the Software; you must not claim
         you created the original Software.
       - If the Software is used in a product, you must either:
         a. Provide clear attribution in the product's documentation, user interface,
            or other visible areas, **OR**
         b. Pay the original developers a fee they specify in writing.
    2. **Usage Restriction**:
       - The Software, or any derivative works, dependencies, or libraries
         incorporating it, must not be used for censorship or to suppress freedom of
         speech, expression, or creativity. Prohibited uses include, but are not
         limited to:
         - Censorship of so-called "hate speech", visuals, non-mainstream opinions,
           ideas, or objective reality.
         - Tools or systems designed to restrict access to information or
           artistic works.
    3. **Notice Preservation**:
       - This license and the above copyright notice must remain intact in all copies
         of the source code.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
namespace Std\Lib\Git;

/**
 * Gitの設定ファイル（config）
 *
 * 「[section]」「[section "subsection"]」と「key = value」。名前はsection.subsection.key
 * （sectionとkeyは小文字、subsectionは大文字・小文字を区別する）。書く時はコメントを残さない。
 */
final class Config {
  /** @var array 名前 => 値の配列（同じ名前が複数有り得る） */
  private array $values = [];

  public function __construct(private ?string $file = null) {
    if ($file !== null && is_file($file)) $this->parse((string)file_get_contents($file));
  }

  public static function fromString(string $text): self {
    $c = new self();
    $c->parse($text);
    return $c;
  }

  private function parse(string $text): void {
    $section = '';
    $lines = preg_split('/\r?\n/', $text);
    for ($i = 0; $i < count($lines); $i++) {
      $line = $lines[$i];
      $t = ltrim($line);
      if ($t === '' || $t[0] === '#' || $t[0] === ';') continue;
      if ($t[0] === '[') {
        if (!preg_match('/^\[\s*([A-Za-z0-9.-]+)(?:\s+"((?:[^"\\\\]|\\\\.)*)")?\s*\](.*)$/', $t, $m)) throw new GitException("不正な設定の行：{$line}");
        $section = strtolower($m[1]);
        if (isset($m[2]) && $m[2] !== '') $section .= '.'.preg_replace('/\\\\(.)/', '$1', $m[2]);
        $t = ltrim($m[3]);
        if ($t === '' || $t[0] === '#' || $t[0] === ';') continue;
      }
      if (!preg_match('/^([A-Za-z][A-Za-z0-9-]*)\s*(=\s*(.*))?$/s', $t, $m)) throw new GitException("不正な設定の行：{$line}");
      $key = $section.'.'.strtolower($m[1]);
      if (!isset($m[2]) || $m[2] === '') {
        $this->values[$key][] = 'true';
        continue;
      }
      $raw = $m[3];
      // 行の最後の「\」で次の行に続く
      while (preg_match('/(?<!\\\\)(\\\\\\\\)*\\\\$/', $raw) && $i + 1 < count($lines)) $raw = substr($raw, 0, -1).$lines[++$i];
      $this->values[$key][] = self::unquote($raw);
    }
  }

  private static function unquote(string $raw): string {
    $out = '';
    $quoted = false;
    $len = strlen($raw);
    $pendingSpace = '';
    for ($i = 0; $i < $len; $i++) {
      $c = $raw[$i];
      if (!$quoted && ($c === '#' || $c === ';')) break;
      if ($c === '"') {
        $quoted = !$quoted;
        continue;
      }
      if ($c === '\\' && $i + 1 < $len) {
        $n = $raw[++$i];
        $out .= $pendingSpace.match ($n) { 'n' => "\n", 't' => "\t", 'b' => "\x08", default => $n };
        $pendingSpace = '';
        continue;
      }
      if (!$quoted && ($c === ' ' || $c === "\t")) {
        // 引用符の外の空白は1つにまとめ、最後の空白は消す
        if ($out !== '' || $pendingSpace !== '') $pendingSpace = ' ';
        continue;
      }
      $out .= $pendingSpace.$c;
      $pendingSpace = '';
    }
    return $out;
  }

  /** 最後の値 */
  public function get(string $name, ?string $default = null): ?string {
    $k = $this->key($name);
    return isset($this->values[$k]) ? end($this->values[$k]) : $default;
  }

  /** 全部の値 */
  public function getAll(string $name): array {
    return $this->values[$this->key($name)] ?? [];
  }

  public function getBool(string $name, bool $default = false): bool {
    $v = $this->get($name);
    if ($v === null) return $default;
    return in_array(strtolower($v), ['true', 'yes', 'on', '1'], true);
  }

  public function getInt(string $name, int $default = 0): int {
    $v = $this->get($name);
    if ($v === null || !preg_match('/^(-?\d+)([kmg]?)$/i', trim($v), $m)) return $default;
    return (int)$m[1] * match (strtolower($m[2])) { 'k' => 1024, 'm' => 1048576, 'g' => 1073741824, default => 1 };
  }

  public function set(string $name, ?string $value): void {
    $k = $this->key($name);
    if ($value === null) unset($this->values[$k]);
    else $this->values[$k] = [$value];
  }

  /** 全部（名前 => 最後の値） */
  public function all(): array {
    return array_map(fn($v) => end($v), $this->values);
  }

  public function toString(): string {
    $sections = [];
    foreach ($this->values as $k => $vals) {
      $p = strrpos($k, '.');
      $sections[substr($k, 0, $p)][substr($k, $p + 1)] = $vals;
    }
    $out = '';
    foreach ($sections as $sec => $keys) {
      $dot = strpos($sec, '.');
      $out .= $dot === false ? "[{$sec}]\n" : '['.substr($sec, 0, $dot).' "'.addcslashes(substr($sec, $dot + 1), '"\\')."\"]\n";
      foreach ($keys as $key => $vals) {
        foreach ($vals as $v) {
          $q = preg_match('/^\s|\s$|[#;"\\\\\n\t]/', $v) ? '"'.str_replace(['\\', '"', "\n", "\t"], ['\\\\', '\\"', '\\n', '\\t'], $v).'"' : $v;
          $out .= "\t{$key} = {$q}\n";
        }
      }
    }
    return $out;
  }

  public function save(?string $file = null): void {
    $file ??= $this->file;
    if ($file === null) throw new GitException('設定ファイルが有りません。');
    $tmp = $file.'.lock';
    if (@file_put_contents($tmp, $this->toString()) === false || !@rename($tmp, $file)) {
      @unlink($tmp);
      throw new GitException("設定ファイルに書けません：{$file}");
    }
  }

  private function key(string $name): string {
    $first = strpos($name, '.');
    $last = strrpos($name, '.');
    if ($first === false) throw new GitException("不正な設定の名前：{$name}");
    if ($first === $last) return strtolower($name);
    return strtolower(substr($name, 0, $first)).substr($name, $first, $last - $first).'.'.strtolower(substr($name, $last + 1));
  }
}