<?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\Db\Sqlite;

/**
 * SQLiteの値の変換（型の親和性、数値・文字列にする、真偽）
 */
final class Value {
  public const INTEGER = 'INTEGER';
  public const REAL = 'REAL';
  public const NUMERIC = 'NUMERIC';
  public const TEXT = 'TEXT';
  public const BLOB = 'BLOB';

  /**
   * 宣言された型の親和性（SQLiteの規則）
   *
   * @param string $type  例：VARCHAR(255)、BIGINT
   * @return string
   */
  public static function affinity(string $type): string {
    $t = strtoupper($type);
    if (str_contains($t, 'INT')) return self::INTEGER;
    if (str_contains($t, 'CHAR') || str_contains($t, 'CLOB') || str_contains($t, 'TEXT')) return self::TEXT;
    if ($t === '' || str_contains($t, 'BLOB')) return self::BLOB;
    if (str_contains($t, 'REAL') || str_contains($t, 'FLOA') || str_contains($t, 'DOUB')) return self::REAL;
    return self::NUMERIC;
  }

  /** CASTの型の親和性（空ならBLOB） */
  public static function castAffinity(string $type): string {
    return trim($type) === '' ? self::BLOB : self::affinity($type);
  }

  /**
   * 列に入れる時の親和性を適用する
   */
  public static function apply(mixed $v, string $aff): mixed {
    if ($v === null || $v instanceof Blob) return $v;
    switch ($aff) {
      case self::TEXT:
        return is_string($v) ? $v : self::toText($v);
      case self::INTEGER:
      case self::NUMERIC:
        if (is_string($v)) {
          $n = self::parseNumber($v, true);
          if ($n === null) return $v;
          $v = $n;
        }
        if (is_float($v) && is_finite($v) && floor($v) === $v && abs($v) < 9.2233720368547e18) return (int)$v;
        return $v;
      case self::REAL:
        if (is_string($v)) {
          $n = self::parseNumber($v, true);
          return $n === null ? $v : (float)$n;
        }
        return (float)$v;
    }
    return $v;
  }

  /**
   * 文字列全部が数値なら数値（前後の空白は可）
   *
   * @param bool $whole  trueなら全部が数値の場合だけ、falseなら先頭の数値（無ければ0）
   * @return int|float|null
   */
  public static function parseNumber(string $s, bool $whole): int|float|null {
    if (preg_match('/^\s*([+-]?)(\d+)(\.\d*)?([eE][+-]?\d+)?\s*$/', $s, $m)
        || preg_match('/^\s*([+-]?)()(\.\d+)([eE][+-]?\d+)?\s*$/', $s, $m)) {
      if (($m[3] ?? '') === '' && ($m[4] ?? '') === '') {
        $digits = ltrim($m[2], '0');
        if ($digits === '') return 0;
        if (strlen($digits) < 19 || (strlen($digits) === 19 && strcmp($digits, $m[1] === '-' ? '9223372036854775808' : '9223372036854775807') <= 0)) {
          if ($m[1] === '-' && $digits === '9223372036854775808') return PHP_INT_MIN;
          return (int)($m[1].$digits);
        }
      }
      return (float)trim($s);
    }
    if ($whole) {
      // 16進数・無限
      if (preg_match('/^\s*[+-]?(inf|infinity)\s*$/i', $s)) return null;
      return null;
    }
    if (preg_match('/^\s*[+-]?(\d+(\.\d*)?|\.\d+)([eE][+-]?\d+)?/', $s, $m)) {
      return self::parseNumber($m[0], true) ?? 0;
    }
    return 0;
  }

  /** 計算用の数値（NULLはnull、文字列は先頭の数値） */
  public static function toNumber(mixed $v): int|float|null {
    if ($v === null || is_int($v) || is_float($v)) return $v;
    if ($v instanceof Blob) $v = $v->data;
    return self::parseNumber((string)$v, false);
  }

  /** 整数（CAST AS INTEGER） */
  public static function toInt(mixed $v): ?int {
    $n = self::toNumber($v);
    if ($n === null) return null;
    if (is_float($n)) {
      if (is_nan($n)) return 0;
      if ($n >= 9.2233720368547758e18) return PHP_INT_MAX;
      if ($n <= -9.2233720368547758e18) return PHP_INT_MIN;
      return (int)$n;
    }
    return $n;
  }

  /** 文字列にする（数値はSQLiteと同じ形） */
  public static function toText(mixed $v): ?string {
    if ($v === null) return null;
    if (is_int($v)) return (string)$v;
    if (is_float($v)) return self::realToText($v);
    if ($v instanceof Blob) return $v->data;
    return (string)$v;
  }

  /** REALの文字列（%!.15gと同じ） */
  public static function realToText(float $f): string {
    if (is_nan($f)) return 'NaN';
    if (is_infinite($f)) return $f > 0 ? 'Inf' : '-Inf';
    if ($f == 0.0) return '0.0';
    $e = sprintf('%.14e', $f);
    [$mant, $exp] = explode('e', $e);
    $exp = (int)$exp;
    if ($exp < -4 || $exp >= 15) {
      $mant = rtrim(rtrim($mant, '0'), '.');
      if (!str_contains($mant, '.')) $mant .= '.0';
      return $mant.'e'.($exp < 0 ? '-' : '+').str_pad((string)abs($exp), 2, '0', STR_PAD_LEFT);
    }
    $s = sprintf('%.'.max(0, 14 - $exp).'F', $f);
    if (str_contains($s, '.')) $s = rtrim(rtrim($s, '0'), '.');
    if (!str_contains($s, '.')) $s .= '.0';
    return $s;
  }

  /**
   * 真偽（NULLはnull）
   */
  public static function truth(mixed $v): ?bool {
    if ($v === null) return null;
    if (is_int($v)) return $v !== 0;
    if (is_float($v)) return $v != 0.0;
    $n = self::toNumber($v);
    return $n != 0;
  }

  /**
   * 比べる前の親和性（SQLiteの比較の規則）
   *
   * @param array $l  [値, 親和性]
   * @param array $r  [値, 親和性]
   * @return array  [左の値, 右の値]
   */
  public static function prepareCompare(mixed $a, string $affA, mixed $b, string $affB): array {
    $numA = $affA === self::INTEGER || $affA === self::REAL || $affA === self::NUMERIC;
    $numB = $affB === self::INTEGER || $affB === self::REAL || $affB === self::NUMERIC;
    if ($numA && !$numB) {
      if (is_string($b)) $b = self::apply($b, self::NUMERIC);
    } else if ($numB && !$numA) {
      if (is_string($a)) $a = self::apply($a, self::NUMERIC);
    } else if ($affA === self::TEXT && $affB === '') {
      if (is_int($b) || is_float($b)) $b = self::toText($b);
    } else if ($affB === self::TEXT && $affA === '') {
      if (is_int($a) || is_float($a)) $a = self::toText($a);
    }
    return [$a, $b];
  }

  /** SQLのリテラル（quote()） */
  public static function quote(mixed $v): string {
    if ($v === null) return 'NULL';
    if (is_int($v)) return (string)$v;
    if (is_float($v)) return self::realToText($v);
    if ($v instanceof Blob) return "X'".strtoupper(bin2hex($v->data))."'";
    return "'".str_replace("'", "''", (string)$v)."'";
  }

  /** typeof() */
  public static function type(mixed $v): string {
    if ($v === null) return 'null';
    if (is_int($v)) return 'integer';
    if (is_float($v)) return 'real';
    if ($v instanceof Blob) return 'blob';
    return 'text';
  }

  /** GROUP BY・DISTINCT用のキー */
  public static function key(mixed $v, string $coll = 'BINARY'): string {
    if ($v === null) return 'n';
    if (is_int($v)) return 'i'.$v;
    if (is_float($v)) {
      if (is_finite($v) && floor($v) === $v && abs($v) < 9.2e18) return 'i'.(int)$v;
      return 'f'.$v;
    }
    if ($v instanceof Blob) return 'b'.strlen($v->data).':'.$v->data;
    $s = (string)$v;
    if ($coll === 'NOCASE') $s = strtolower($s);
    else if ($coll === 'RTRIM') $s = rtrim($s, ' ');
    return 's'.strlen($s).':'.$s;
  }
}