use crate::config::{manager::ConfigManager, OPNsenseShell};
use crate::error::Error;
use async_trait::async_trait;
use log::{info, warn};
use russh_keys::key::KeyPair;
use sha2::Digest;
use std::sync::Arc;

#[derive(Debug)]
pub enum SshCredentials {
    SshKey { username: String, key: Arc<KeyPair> },
    Password { username: String, password: String },
}

#[derive(Debug)]
pub struct SshConfigManager {
    opnsense_shell: Arc<dyn OPNsenseShell>,
}

impl SshConfigManager {
    pub fn new(opnsense_shell: Arc<dyn OPNsenseShell>) -> Self {
        Self { opnsense_shell }
    }
}

impl SshConfigManager {
    async fn backup_config_remote(&self) -> Result<String, Error> {
        let ts = chrono::Utc::now();
        let backup_filename = format!("config-{}-harmony.xml", ts.format("%s%.3f"));

        self.opnsense_shell
            .exec(&format!(
                "cp /conf/config.xml /conf/backup/{}",
                backup_filename
            ))
            .await
    }

    async fn copy_to_live_config(&self, new_config_path: &str) -> Result<String, Error> {
        info!("Overwriting OPNSense /conf/config.xml with {new_config_path}");
        self.opnsense_shell
            .exec(&format!("cp {new_config_path} /conf/config.xml"))
            .await
    }

    async fn reload_all_services(&self) -> Result<String, Error> {
        info!("Reloading all opnsense services");
        self.opnsense_shell
            .exec("configctl service reload all")
            .await
    }
}

#[async_trait]
impl ConfigManager for SshConfigManager {
    async fn load_as_str(&self) -> Result<String, Error> {
        self.opnsense_shell.exec("cat /conf/config.xml").await
    }

    async fn save_config(&self, content: &str, hash: &str) -> Result<(), Error> {
        let current_content = self.load_as_str().await?;

        if !check_hash(&current_content, hash) {
            warn!("OPNSense config file changed since loading it! Hash when loading : {hash}");
            // return Err(Error::Config(format!(
            //     "OPNSense config file changed since loading it! Hash when loading : {hash}"
            // )));
        }

        let temp_filename = self
            .opnsense_shell
            .write_content_to_temp_file(content)
            .await?;
        self.backup_config_remote().await?;
        self.copy_to_live_config(&temp_filename).await?;
        Ok(())
    }

    async fn apply_new_config(&self, content: &str, hash: &str) -> Result<(), Error> {
        self.save_config(content, &hash).await?;
        self.reload_all_services().await?;
        Ok(())
    }
}

pub fn get_hash(content: &str) -> String {
    let mut hasher = sha2::Sha256::new();
    hasher.update(content.as_bytes());
    let hash_bytes = hasher.finalize();
    let hash_string = format!("{:x}", hash_bytes);
    info!("Loaded OPNSense config.xml with hash {hash_string:?}");
    hash_string
}

pub fn check_hash(content: &str, source_hash: &str) -> bool {
    get_hash(content) == source_hash
}