use std::borrow::Cow;
use std::error::Error;
use std::fmt;

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

pub struct PostgreSQLDatabase<'a, C: 'a + CommandRunner> {
  name: Cow<'a, str>,
  seed_file: Cow<'a, str>,
  command_runner: &'a C,
}

impl<'a, C: CommandRunner> PostgreSQLDatabase<'a, C> {
  pub fn new(name: Cow<'a, str>, seed_file: Cow<'a, str>, command_runner: &'a C) -> Self {
    PostgreSQLDatabase {
      name,
      seed_file,
      command_runner,
    }
  }

  fn run_sql(&self, sql: &str) -> Result<String, Box<dyn Error>> {
    let b = self.command_runner.get_output(
      "su",
      &["-", "postgres", "-c", &format!("psql -t -c \"{}\"", sql)],
    )?;
    Ok(String::from_utf8(b)?)
  }
}

impl<'a, C: CommandRunner> fmt::Display for PostgreSQLDatabase<'a, C> {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
    write!(f, "PostgreSQL Database {}", self.name)
  }
}

impl<'a, C: CommandRunner> Symbol for PostgreSQLDatabase<'a, C> {
  fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
    Ok(
      self
        .run_sql(&format!(
          "SELECT datname FROM pg_database WHERE datname LIKE '{}'",
          self.name
        ))?
        .trim()
        == self.name,
    )
  }

  fn execute(&self) -> Result<(), Box<dyn Error>> {
    self.command_runner.run_successfully(
      "su",
      &["-", "postgres", "-c", &format!("createuser {}", self.name)],
    )?;
    self.command_runner.run_successfully(
      "su",
      &[
        "-",
        "postgres",
        "-c",
        &format!("createdb -E UTF8 -T template0 -O {} {0}", self.name),
      ],
    )?;
    self.command_runner.run_successfully(
      "su",
      &[
        "-",
        "postgres",
        "-c",
        &format!("psql '{}' < {}", self.name, self.seed_file),
      ],
    )
  }

  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 {}