// SPDX-FileCopyrightText: 2020 Serokell <https://serokell.io/>
//
// SPDX-License-Identifier: MPL-2.0

use std::borrow::Cow;
use tokio::process::Command;

use thiserror::Error;

fn build_activate_command(
    sudo: &Option<String>,
    profile_path: &str,
    closure: &str,
    auto_rollback: bool,
    temp_path: &Cow<str>,
    confirm_timeout: u16,
    magic_rollback: bool,
) -> String {
    let mut self_activate_command = format!(
        "{}/activate-rs '{}' '{}' --temp-path {} --confirm-timeout {}",
        closure, profile_path, closure, temp_path, confirm_timeout
    );

    if magic_rollback {
        self_activate_command = format!("{} --magic-rollback", self_activate_command);
    }

    if auto_rollback {
        self_activate_command = format!("{} --auto-rollback", self_activate_command);
    }

    if let Some(sudo_cmd) = &sudo {
        self_activate_command = format!("{} {}", sudo_cmd, self_activate_command);
    }

    self_activate_command
}

#[test]
fn test_activation_command_builder() {
    let activate_path_str = "/blah/bin/activate".to_string();
    let sudo = Some("sudo -u test".to_string());
    let profile_path = "/blah/profiles/test";
    let closure = "/nix/store/blah/etc";
    let auto_rollback = true;
    let temp_path = &"/tmp".into();
    let confirm_timeout = 30;
    let magic_rollback = true;

    assert_eq!(
        build_activate_command(
            &sudo,
            profile_path,
            closure,
            auto_rollback,
            temp_path,
            confirm_timeout,
            magic_rollback
        ),
        "sudo -u test /nix/store/blah/etc/activate-rs '/blah/profiles/test' '/nix/store/blah/etc' --temp-path /tmp --confirm-timeout 30 --magic-rollback --auto-rollback"
            .to_string(),
    );
}

#[derive(Error, Debug)]
pub enum DeployProfileError {
    #[error("Failed to calculate activate bin path from deploy bin path: {0}")]
    DeployPathToActivatePathError(#[from] super::DeployPathToActivatePathError),
    #[error("Failed to run activation command over SSH: {0}")]
    SSHActivateError(std::io::Error),
    #[error("Activation over SSH resulted in a bad exit code: {0:?}")]
    SSHActivateExitError(Option<i32>),
    #[error("Failed to run confirmation command over SSH (the server should roll back): {0}")]
    SSHConfirmError(std::io::Error),
    #[error(
        "Confirming activation over SSH resulted in a bad exit code (the server should roll back): {0:?}"
    )]
    SSHConfirmExitError(Option<i32>),
}

pub async fn deploy_profile(
    deploy_data: &super::DeployData<'_>,
    deploy_defs: &super::DeployDefs,
) -> Result<(), DeployProfileError> {
    info!(
        "Activating profile `{}` for node `{}`",
        deploy_data.profile_name, deploy_data.node_name
    );

    let temp_path: Cow<str> = match &deploy_data.merged_settings.temp_path {
        Some(x) => x.into(),
        None => "/tmp".into(),
    };

    let confirm_timeout = deploy_data.merged_settings.confirm_timeout.unwrap_or(30);

    let magic_rollback = deploy_data.merged_settings.magic_rollback.unwrap_or(true);

    let auto_rollback = deploy_data.merged_settings.auto_rollback.unwrap_or(true);

    let self_activate_command = build_activate_command(
        &deploy_defs.sudo,
        &deploy_defs.profile_path,
        &deploy_data.profile.profile_settings.path,
        auto_rollback,
        &temp_path,
        confirm_timeout,
        magic_rollback,
    );

    debug!("Constructed activation command: {}", self_activate_command);

    let hostname = match deploy_data.cmd_overrides.hostname {
        Some(ref x) => x,
        None => &deploy_data.node.node_settings.hostname,
    };

    let mut c = Command::new("ssh");
    let mut ssh_command = c
        .arg("-t")
        .arg(format!("ssh://{}@{}", deploy_defs.ssh_user, hostname));

    for ssh_opt in &deploy_data.merged_settings.ssh_opts {
        ssh_command = ssh_command.arg(ssh_opt);
    }

    let ssh_exit_status = ssh_command
        .arg(self_activate_command)
        .status()
        .await
        .map_err(DeployProfileError::SSHActivateError)?;

    match ssh_exit_status.code() {
        Some(0) => (),
        a => return Err(DeployProfileError::SSHActivateExitError(a)),
    };

    info!("Success activating!");

    if magic_rollback {
        info!("Attempting to confirm activation");

        let mut c = Command::new("ssh");
        let mut ssh_confirm_command = c.arg(format!("ssh://{}@{}", deploy_defs.ssh_user, hostname));

        for ssh_opt in &deploy_data.merged_settings.ssh_opts {
            ssh_confirm_command = ssh_confirm_command.arg(ssh_opt);
        }

        let lock_hash = &deploy_data.profile.profile_settings.path["/nix/store/".len()..];
        let lock_path = format!("{}/deploy-rs-canary-{}", temp_path, lock_hash);

        let mut confirm_command = format!("rm {}", lock_path);
        if let Some(sudo_cmd) = &deploy_defs.sudo {
            confirm_command = format!("{} {}", sudo_cmd, confirm_command);
        }

        debug!(
            "Attempting to run command to confirm deployment: {}",
            confirm_command
        );

        let ssh_exit_status = ssh_confirm_command
            .arg(confirm_command)
            .status()
            .await
            .map_err(DeployProfileError::SSHConfirmError)?;

        match ssh_exit_status.code() {
            Some(0) => (),
            a => return Err(DeployProfileError::SSHConfirmExitError(a)),
        };

        info!("Deployment confirmed.");
    }

    Ok(())
}