use std::error::Error;
use std::fmt;

use crate::command_runner::CommandRunner;
use crate::resources::Resource;
use crate::symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};

pub struct MariaDBUser<'a, U: AsRef<str>, C: CommandRunner> {
  user_name: U,
  command_runner: &'a C,
}

impl<'a, U: AsRef<str>, C: CommandRunner> MariaDBUser<'a, U, C> {
  pub fn new(user_name: U, command_runner: &'a C) -> Self {
    MariaDBUser {
      user_name,
      command_runner,
    }
  }

  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])?;
    Ok(String::from_utf8(b)?)
  }
}

impl<'a, U: AsRef<str>, C: CommandRunner> fmt::Display for MariaDBUser<'a, U, C> {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
    write!(f, "MariaDB User {}", self.user_name.as_ref())
  }
}

impl<'a, U: AsRef<str>, C: CommandRunner> Symbol for MariaDBUser<'a, U, C> {
  fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
    Ok(
      self
        .run_sql(&format!(
          "SELECT User FROM mysql.user WHERE User = '{}' AND plugin = 'unix_socket'",
          self.user_name.as_ref()
        ))?
        .trim_end()
        == self.user_name.as_ref(),
    )
  }

  fn execute(&self) -> Result<(), Box<dyn Error>> {
    self.run_sql(&format!(
      "GRANT ALL ON {0}.* TO {0} IDENTIFIED VIA unix_socket",
      self.user_name.as_ref()
    ))?;
    Ok(())
  }

  fn get_prerequisites(&self) -> Vec<Resource> {
    vec![Resource::new("user", self.user_name.as_ref())]
  }

  fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
    Box::new(SymbolAction::new(runner, self))
  }

  fn into_action<'b>(self: Box<Self>, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b>
  where
    Self: 'b,
  {
    Box::new(OwnedSymbolAction::new(runner, *self))
  }
}

#[cfg(test)]
mod test {}