const sqlite3 = require("sqlite3").verbose();
const path = require("path");

// 获取数据库路径
function getDatabasePath() {
  const dbPath = path.join(__dirname, "..", "..", "live_chat.db");
  return dbPath;
}

// 更新配置值
function updateConfigValue(key, value) {
  return new Promise((resolve, reject) => {
    const db = new sqlite3.Database(getDatabasePath(), err => {
      if (err) {
        console.error("数据库连接错误:", err.message);
        return reject(err);
      }
    });
    // 先尝试更新，如果影响行数为0则插入新记录
    db.run(
      `UPDATE config SET value = ? WHERE key = ?`,
      [value, key],
      function (err) {
        if (err) {
          db.close();
          return reject(err);
        }

        // 如果没有匹配的记录则插入
        if (this.changes === 0) {
          db.run(
            `INSERT INTO config (key, value) VALUES (?, ?)`,
            [key, value],
            function (err) {
              db.close();
              if (err) return reject(err);
              resolve({
                success: true,
                action: "insert",
                changes: this.changes
              });
            }
          );
        } else {
          db.close();
          resolve({ success: true, action: "update", changes: this.changes });
        }
      }
    );
  });
}

// 获取配置值
function getConfigValue(key) {
  return new Promise((resolve, reject) => {
    const db = new sqlite3.Database(getDatabasePath(), err => {
      if (err) {
        return reject(err);
      }
    });

    db.get(`SELECT value FROM config WHERE key = ?`, [key], (err, row) => {
      db.close();
      if (err) return reject(err);
      resolve(row ? row.value : null);
    });
  });
}
// 批量插入系统消息
const bulkInsertSystemMessages = messages => {
  return new Promise((resolve, reject) => {
    if (!Array.isArray(messages) || messages.length === 0) {
      reject(new Error("请提供有效的消息数组"));
      return;
    }

    try {
      const db = new sqlite3.Database(getDatabasePath(), err => {
        if (err) {
          reject(err);
          return;
        }
        // 清空表
        db.run("DELETE FROM system_message", function (err) {
          if (err) {
            db.close();
            reject(err);
            return;
          }

          // 重置自增计数器（SQLite特定）
          db.run(
            "DELETE FROM sqlite_sequence WHERE name = 'system_message'",
            err => {
              if (err) {
                db.close();
                reject(err);
                return;
              } else {
                // 使用事务进行批量插入，提高性能
                db.run("BEGIN TRANSACTION", err => {
                  if (err) {
                    reject(err);
                    db.close();
                    return;
                  }

                  const stmt = db.prepare(
                    "INSERT INTO system_message (message) VALUES (?)"
                  );
                  let completed = 0;
                  let errorOccurred = null;

                  messages.forEach(message => {
                    stmt.run(message, function (err) {
                      if (err && !errorOccurred) {
                        errorOccurred = err;
                      }

                      completed++;

                      // 所有消息都处理完毕
                      if (completed === messages.length) {
                        stmt.finalize();

                        if (errorOccurred) {
                          db.run("ROLLBACK", () => {
                            reject(errorOccurred);
                            db.close();
                          });
                        } else {
                          db.run("COMMIT", err => {
                            if (err) {
                              reject(err);
                            } else {
                              resolve({
                                success: true,
                                count: messages.length
                              });
                            }
                            db.close();
                          });
                        }
                      }
                    });
                  });
                });
              }
            }
          );
        });
      });
    } catch (error) {
      reject(error);
    }
  });
};
module.exports = {
  updateConfigValue,
  getConfigValue,
  bulkInsertSystemMessages
};