<?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
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 */
namespace Std\Lib\Db\Convert;

use Std\Lib\Db;
use Std\Lib\Db\Convert;
use Std\Lib\Db\DbException;
use Std\Lib\Db\Sqlite\Blob;

/**
 * データベース（MySQL・PostgreSQL・SQLite）に書く
 *
 * テーブルを作って、行を入れてから、インデックスを作る。PostgreSQLの自動の番号（SERIAL）は最後に続きの番号にする。
 */
final class DbTarget implements Target {
  public string $dialect;
  private array $warnings = [];
  private array $stmts = [];
  private bool $inTx = false;
  private int $pending = 0;

  public function __construct(private Db $db) {
    $this->dialect = DbSource::dialectOf($db);
  }

  public function warnings(): array {
    return array_values(array_unique($this->warnings));
  }

  private function q(string $n): string {
    return Convert::quote($this->dialect, $n);
  }

  public function begin(bool $drop): void {
    $this->drop = $drop;
    $this->existing = array_map('strtolower', DbSource::tableNames($this->db));
    if ($this->dialect === 'mysql') $this->db->query('SET FOREIGN_KEY_CHECKS = 0');
  }

  private bool $drop = false;
  private array $existing = [];

  public function createTable(array $t): void {
    if (in_array(strtolower($t['name']), $this->existing, true)) {
      if (!$this->drop) throw new DbException("テーブル{$t['name']}は既に有ります（消す場合は「drop」）", 0, 'HY000');
      $this->db->query('DROP TABLE '.$this->q($t['name']).($this->dialect === 'pgsql' ? ' CASCADE' : ''));
    }
    $this->db->query(Convert::createTable($this->dialect, $t, $this->warnings));
  }

  public function insertRows(array $t, array $rows): void {
    $nc = count($t['columns']);
    $per = max(1, min(500, intdiv(30000, max(1, $nc))));
    $drv = $this->db->driver();
    $drv->connect();
    if (!$this->inTx) {
      $drv->beginTransaction();
      $this->inTx = true;
    }
    foreach (array_chunk($rows, $per) as $chunk) {
      $n = count($chunk);
      $key = $t['name']."\0".$n;
      if (!isset($this->stmts[$key])) {
        $ph = '('.implode(', ', array_fill(0, $nc, '?')).')';
        $sql = 'INSERT INTO '.$this->q($t['name']).' ('.implode(', ', array_map(fn($c) => $this->q($c['name']), $t['columns'])).') VALUES '
          .implode(', ', array_fill(0, $n, $ph));
        if (count($this->stmts) > 20) {
          foreach ($this->stmts as $id) $drv->demolish($id);
          $this->stmts = [];
        }
        $this->stmts[$key] = $drv->prepare($sql);
      }
      $params = [];
      foreach ($chunk as $r) {
        foreach ($t['columns'] as $i => $c) $params[] = $this->param($r[$i], $c, $t);
      }
      $drv->execute($this->stmts[$key], $params);
      $this->pending += $n;
      if ($this->pending >= 20000) {
        $drv->commit();
        $drv->beginTransaction();
        $this->pending = 0;
      }
    }
  }

  private function param(mixed $v, array $c, array $t): mixed {
    if ($v === null) return null;
    if ($v instanceof Blob) return $this->dialect === 'sqlite' ? $v : $v->data;
    if (is_bool($v)) return $this->dialect === 'pgsql' ? $v : (int)$v;
    if (is_float($v) && (is_nan($v) || is_infinite($v)) && $this->dialect !== 'pgsql') {
      if ($this->dialect === 'mysql' || is_nan($v)) {
        $this->warnings[] = "NaN・無限はNULLにしました：{$t['name']}.{$c['name']}";
        return null;
      }
    }
    if (is_string($v) && $this->dialect === 'pgsql' && str_contains($v, "\0")) {
      $this->warnings[] = "PostgreSQLの文字列に0のバイトは入れられないので、消しました：{$t['name']}.{$c['name']}";
      return str_replace("\0", '', $v);
    }
    return $v;
  }

  public function finishTable(array $t): void {
    $drv = $this->db->driver();
    if ($this->inTx) {
      $drv->commit();
      $this->inTx = false;
      $this->pending = 0;
    }
    foreach ($t['indexes'] as $idx) $this->db->query(Convert::createIndex($this->dialect, $t, $idx));
    if ($this->dialect === 'pgsql') {
      foreach ($t['columns'] as $c) {
        if (!$c['autoinc'] || count($t['pk']) !== 1 || strcasecmp($t['pk'][0], $c['name']) !== 0) continue;
        $this->db->query("SELECT setval(pg_get_serial_sequence(?, ?), COALESCE(MAX({$this->q($c['name'])}), 1), MAX({$this->q($c['name'])}) IS NOT NULL) FROM {$this->q($t['name'])}",
                         [$this->q($t['name']), $c['name']]);
      }
    }
  }

  public function abort(): void {
    $drv = $this->db->driver();
    try {
      if ($this->inTx && $drv->inTransaction()) $drv->rollback();
    } catch (\Throwable $e) {
      // 接続が切れた等
    }
    $this->inTx = false;
    $this->stmts = [];
  }

  public function end(): void {
    $drv = $this->db->driver();
    foreach ($this->stmts as $id) $drv->demolish($id);
    $this->stmts = [];
    if ($this->inTx) {
      $drv->commit();
      $this->inTx = false;
    }
    if ($this->dialect === 'mysql') $this->db->query('SET FOREIGN_KEY_CHECKS = 1');
  }
}