use crate::command_runner::CommandRunner;
use crate::storage::Storage;
use crate::symbols::Symbol;
use async_trait::async_trait;
use std::error::Error;
use std::str::FromStr;

#[derive(Debug)]
pub struct Dump<'a, N, C, S> {
  db_name: N,
  storage: S,
  command_runner: &'a C,
}

impl<'a, N, C: CommandRunner, S> Dump<'a, N, C, S> {
  pub fn new(db_name: N, storage: S, command_runner: &'a C) -> Self {
    Self {
      db_name,
      storage,
      command_runner,
    }
  }

  async fn run_sql(&self, sql: &str) -> Result<String, Box<dyn Error>> {
    let b = self
      .command_runner
      .get_output("mariadb", args!["--skip-column-names", "-B", "-e", sql])
      .await?;
    Ok(String::from_utf8(b)?)
  }
}

#[async_trait(?Send)]
impl<N: AsRef<str>, C: CommandRunner, S: Storage> Symbol for Dump<'_, N, C, S> {
  async fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
    let dump_date = self.storage.recent_date()?;
    let output = self.run_sql(&format!("select UNIX_TIMESTAMP(MAX(UPDATE_TIME)) from information_schema.tables WHERE table_schema = '{}'", self.db_name.as_ref())).await?;
    let modified_date = output.trim_end();
    Ok(modified_date != "NULL" && u64::from_str(modified_date)? <= dump_date)
  }

  async fn execute(&self) -> Result<(), Box<dyn Error>> {
    self
      .command_runner
      .run_successfully(
        "sh",
        args![
          "-c",
          format!(
            "mysqldump '{}' > {}",
            self.db_name.as_ref(),
            self.storage.write_filename().to_str().unwrap()
          ),
        ],
      )
      .await
  }
}

#[cfg(test)]
mod test {}