<?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\Convert;

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

/**
 * LittleBeastのJSONのデータ（data/）に書く（Storesを参照）
 *
 * lb_のテーブルは元のファイルにし、他のテーブルはdata/db/{テーブル}.jsonにする。
 * 書く先のディレクトリが空でない場合は、$overwriteが必要（同じ名前のファイルは置き換え、他のファイルはそのまま）。
 */
final class JsonTarget implements Target {
  private array $warnings = [];
  private array $buf = [];
  private array $open = [];
  private array $first = [];

  /**
   * @param string $dir  データのディレクトリ
   * @param bool $overwrite  空でないディレクトリに書く
   */
  public function __construct(private string $dir, private bool $overwrite = false) {
    $this->dir = rtrim($dir, '/\\');
  }

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

  public function begin(bool $drop): void {
    if (is_dir($this->dir)) {
      $empty = count(array_diff(scandir($this->dir) ?: [], ['.', '..'])) === 0;
      if (!$empty && !$this->overwrite && !$drop) throw new DbException("ディレクトリが空ではありません：{$this->dir}", 0, 'HY000');
    } else if (!@mkdir($this->dir, 0755, true) && !is_dir($this->dir)) {
      throw new DbException("ディレクトリを作れません：{$this->dir}", 0, 'HY000');
    }
  }

  private function path(string $rel): string {
    if (!Stores::safePath($rel)) throw new DbException("不正なパス：{$rel}", 0, 'HY000');
    $p = $this->dir.'/'.$rel;
    $d = dirname($p);
    if (!is_dir($d) && !@mkdir($d, 0755, true) && !is_dir($d)) throw new DbException("ディレクトリを作れません：{$d}", 0, 'HY000');
    return $p;
  }

  private function put(string $rel, string $data): void {
    $p = $this->path($rel);
    $tmp = $p.'.'.bin2hex(random_bytes(4)).'.tmp';
    if (file_put_contents($tmp, $data) === false || !rename($tmp, $p)) {
      @unlink($tmp);
      throw new DbException("ファイルに書けません：{$p}", 0, 'HY000');
    }
  }

  public function createTable(array $t): void {
    $l = strtolower($t['name']);
    if (isset(Stores::tables()[$l])) {
      $this->buf[$l] = [];
      return;
    }
    // 普通のテーブル：定義を書いて、行を追加していく
    $p = $this->path(Stores::tableFile($t['name']));
    $fh = @fopen($p.'.tmp', 'wb');
    if ($fh === false) throw new DbException("ファイルに書けません：{$p}", 0, 'HY000');
    $head = ['table' => $t['name'], 'columns' => array_map(fn($c) => array_filter($c, fn($v) => $v !== null && $v !== false) + ['name' => $c['name'], 'type' => $c['type']], $t['columns']),
             'pk' => $t['pk'], 'indexes' => $t['indexes']];
    foreach ($head['columns'] as $i => $c) {
      if (isset($c['default']['value'])) $head['columns'][$i]['default']['value'] = self::jsonValue($c['default']['value']);
    }
    $json = json_encode($head, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
    fwrite($fh, substr($json, 0, -1).",\"rows\":[\n");
    $this->open[$l] = [$fh, $p];
    $this->first[$l] = true;
  }

  /** JSONに入れる値（BLOBとNaN・無限） */
  public static function jsonValue(mixed $v): mixed {
    if ($v instanceof Blob) return ['$blob' => base64_encode($v->data)];
    if (is_float($v) && (is_nan($v) || is_infinite($v))) return ['$float' => is_nan($v) ? 'NaN' : ($v > 0 ? 'Infinity' : '-Infinity')];
    return $v;
  }

  public function insertRows(array $t, array $rows): void {
    $l = strtolower($t['name']);
    if (isset($this->buf[$l])) {
      // 列の名前で（書く先で列の順番が違っても良い様に）
      foreach ($rows as $r) {
        $row = [];
        foreach ($t['columns'] as $i => $c) $row[strtolower($c['name'])] = $r[$i];
        $this->buf[$l][] = $row;
      }
      return;
    }
    [$fh] = $this->open[$l];
    $out = '';
    foreach ($rows as $r) {
      $line = json_encode(array_map([self::class, 'jsonValue'], $r), JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRESERVE_ZERO_FRACTION | JSON_INVALID_UTF8_SUBSTITUTE);
      $out .= ($this->first[$l] ? '' : ",\n").$line;
      $this->first[$l] = false;
    }
    fwrite($fh, $out);
  }

  public function finishTable(array $t): void {
    $l = strtolower($t['name']);
    if (!isset($this->open[$l])) return;
    [$fh, $p] = $this->open[$l];
    fwrite($fh, "\n]}\n");
    fclose($fh);
    rename($p.'.tmp', $p);
    unset($this->open[$l]);
  }

  public function end(): void {
    $b = $this->buf;
    $col = fn(array $r, string $k) => $r[$k] ?? null;
    $decode = function(mixed $v, string $what) {
      if (is_array($v) || $v === null) return $v;
      $d = json_decode((string)$v, true);
      if (json_last_error() !== JSON_ERROR_NONE) throw new DbException("不正なJSON：{$what}", 0, 'HY000');
      return $d;
    };
    $seqSort = fn(array &$rows) => usort($rows, fn($a, $b) => (int)$a['seq'] <=> (int)$b['seq']);

    foreach ($b['lb_users'] ?? [] as $r) {
      $name = (string)$col($r, 'username');
      if (!preg_match('/^[A-Za-z0-9]+$/', $name) || !is_numeric($col($r, 'id'))) throw new DbException("不正なユーザー：{$name}", 0, 'HY000');
      $decode($r['data'], "lb_users.{$name}");
      $this->put('user/'.(int)$r['id'].'.'.$name.'.json', (string)$r['data']);
    }

    $threads = [];
    foreach ($b['lb_comment_threads'] ?? [] as $r) $threads[(string)$r['thread']] = $decode($r['data'], 'lb_comment_threads') ?: [];
    $comments = [];
    foreach ($b['lb_comments'] ?? [] as $r) $comments[(string)$r['thread']][] = $r;
    foreach ($comments as $thread => $list) $threads[$thread] ??= [];
    foreach ($threads as $thread => $doc) {
      if (!Stores::safeThread($thread)) throw new DbException("不正なスレッド：{$thread}", 0, 'HY000');
      $list = $comments[$thread] ?? [];
      $seqSort($list);
      $doc = is_array($doc) ? $doc : [];
      $doc['comments'] = [];
      foreach ($list as $r) $doc['comments'][(string)$r['id']] = $decode($r['data'], "lb_comments.{$thread}");
      $this->put("comments/{$thread}.json", (string)json_encode($doc, Stores::JSON_FLAGS));
    }

    if (!empty($b['lb_comment_ap'])) {
      $map = [];
      foreach ($b['lb_comment_ap'] as $r) $map[(string)$r['ap_id']] = $decode($r['data'], 'lb_comment_ap');
      $this->put('comments/ap.json', (string)json_encode($map, Stores::JSON_FLAGS));
    }

    $notes = [];
    foreach ($b['lb_notifications'] ?? [] as $r) $notes[(string)$r['username']][] = $r;
    foreach ($notes as $user => $list) {
      if (!Stores::safeName($user)) throw new DbException("不正なユーザー：{$user}", 0, 'HY000');
      $seqSort($list);
      $this->put("notifications/{$user}.json", (string)json_encode(array_map(fn($r) => $decode($r['data'], 'lb_notifications'), $list), Stores::JSON_FLAGS));
    }

    if (isset($b['lb_cron'])) {
      $list = $b['lb_cron'];
      $seqSort($list);
      $this->put('cron/cron.json', (string)json_encode(array_map(fn($r) => $decode($r['data'], 'lb_cron'), $list), Stores::JSON_FLAGS));
    }

    foreach (['lb_followers' => 'followers.txt', 'lb_following' => 'following.txt'] as $t => $file) {
      if (!isset($b[$t])) continue;
      $list = $b[$t];
      $seqSort($list);
      $lines = array_values(array_filter(array_map(fn($r) => trim((string)$r['actor']), $list), fn($l) => $l !== ''));
      $this->put($file, empty($lines) ? '' : implode("\n", $lines)."\n");
    }

    foreach ($b['lb_ap_notes'] ?? [] as $r) {
      $id = (string)$r['id'];
      if (!Stores::safeName($id)) throw new DbException("不正なID：{$id}", 0, 'HY000');
      $decode($r['data'], "lb_ap_notes.{$id}");
      $this->put("ap/notes/{$id}.json", (string)$r['data']);
    }

    foreach ($b['lb_files'] ?? [] as $r) {
      $c = $r['content'];
      $this->put((string)$r['path'], $c instanceof Blob ? $c->data : (string)$c);
    }
    $this->buf = [];
  }

  public function abort(): void {
    foreach ($this->open as [$fh, $p]) {
      @fclose($fh);
      @unlink($p.'.tmp');
    }
    $this->open = [];
    $this->buf = [];
  }
}