<?php
namespace nur\sery\db\sqlite;

use Generator;
use nur\sery\cl;
use SQLite3;
use SQLite3Result;
use SQLite3Stmt;

/**
 * Class Sqlite: frontend vers une base de données sqlite3
 */
class Sqlite {
  static function config_enableExceptions(self $sqlite) {
    $sqlite->db->enableExceptions(true);
  }

  const CONFIG = [
    [self::class, "config_enableExceptions"],
  ];
  const MIGRATE = null;

  const SCHEMA = [
    "file" => ["string", ""],
    "flags" => ["int", SQLITE3_OPEN_READWRITE + SQLITE3_OPEN_CREATE],
    "encryption_key" => ["string", ""],
    "config" => ["?array|callable"],
    "migrate" => ["?array|string|callable"],
    "auto_open" => ["bool", true],
  ];

  function __construct(?string $file=null, ?array $params=null) {
    if ($file !== null) $params["file"] = $file;
    ##schéma
    $default_file = self::SCHEMA["file"][1];
    $this->file = strval($params["file"] ?? $default_file);
    #
    $default_flags = self::SCHEMA["flags"][1];
    $this->flags = intval($params["flags"] ?? $default_flags);
    #
    $default_encryptionKey = self::SCHEMA["encryption_key"][1];
    $this->encryptionKey = strval($params["encryption_key"] ?? $default_encryptionKey);
    # configuration
    $this->config = $params["config"] ?? static::CONFIG;
    # migrations
    $this->migration = $params["migrate"] ?? static::MIGRATE;
    #
    $default_autoOpen = self::SCHEMA["auto_open"][1];
    if ($params["auto_open"] ?? $default_autoOpen) {
      $this->open();
    }
  }

  /** @var string */
  protected $file;

  /** @var int */
  protected $flags;

  /** @var string */
  protected $encryptionKey;

  /** @var array|string|callable */
  protected $config;

  /** @var array|string|callable */
  protected $migration;

  /** @var SQLite3 */
  protected $db;

  function open(): self {
    if ($this->db === null) {
      $this->db = new SQLite3($this->file, $this->flags, $this->encryptionKey);
      _Config::with($this->config)->configure($this);
      _Migration::with($this->migration)->migrate($this);
    }
    return $this;
  }

  function close(): void {
    if ($this->db !== null) {
      $this->db->close();
      $this->db = null;
    }
  }

  protected function checkStmt($stmt): SQLite3Stmt {
    return SqliteException::check($this->db, $stmt);
  }

  protected function checkResult($result): SQLite3Result {
    return SqliteException::check($this->db, $result);
  }

  function _exec(string $query): bool {
    $this->open();
    return $this->db->exec($query);
  }

  function exec($query, ?array $params=null): bool {
    $this->open();
    $query = new _Query($query, $params);
    $db = $this->db;
    if ($query->useStmt($db, $stmt, $sql)) {
      try {
        return $stmt->execute()->finalize();
      } finally {
        $stmt->close();
      }
    } else {
      return $db->exec($sql);
    }
  }

  function _get(string $query, bool $entireRow=false) {
    $this->open();
    return $this->db->querySingle($query, $entireRow);
  }

  function get($query, ?array $params=null, bool $entireRow=false) {
    $this->open();
    $query = new _Query($query, $params);
    $db = $this->db;
    if ($query->useStmt($db, $stmt, $sql)) {
      try {
        $result = $this->checkResult($stmt->execute());
        try {
          $row = $result->fetchArray(SQLITE3_ASSOC);
          if ($row === false) return null;
          elseif ($entireRow) return $row;
          else return cl::first($row);
        } finally {
          $result->finalize();
        }
      } finally {
        $stmt->close();
      }
    } else {
      return $db->querySingle($sql, $entireRow);
    }
  }

  protected function _fetchResult(SQLite3Result $result): Generator {
    try {
      while (($row = $result->fetchArray(SQLITE3_ASSOC)) !== false) {
        yield $row;
      }
    } finally {
      $result->finalize();
    }
  }

  function all($query, ?array $params=null): iterable {
    $this->open();
    $query = new _Query($query, $params);
    $db = $this->db;
    if ($query->useStmt($db, $stmt, $sql)) {
      try {
        $result = $this->checkResult($stmt->execute());
        return $this->_fetchResult($result);
      } finally {
        $stmt->close();
      }
    } else {
      $result = $this->checkResult($db->query($sql));
      return $this->_fetchResult($result);
    }
  }
}