use std::{fs, path::PathBuf};

use log::{debug, error, info};
use semver::Version;
use std::str::FromStr;
use thiserror::Error;

use crate::schemas::{BoardConfig, BoardType, OTAConfiguration, Services};

pub fn parse_mac_address(mac: &str) -> Result<[u8; 6], MacAddressError> {
    if mac.len() != 12 {
        return Err(MacAddressError::Length(mac.len()));
    }

    let mut mac_bytes = [0u8; 6];
    for i in 0..6 {
        let hex_part = &mac[i * 2..i * 2 + 2];
        mac_bytes[i] = u8::from_str_radix(hex_part, 16)?;
    }

    Ok(mac_bytes)
}

#[derive(Error, Debug)]
pub enum MacAddressError {
    #[error("Error converting MAC Address")]
    Conversion(#[from] std::num::ParseIntError),
    #[error("MAC Address length mismatch")]
    Length(usize),
}

#[derive(Error, Debug)]
pub enum GetFilesError {
    #[error("IO Error while reading files")]
    IO(#[from] std::io::Error),
    #[error("Error getting filename")]
    Filename,
    #[error("Error getting extension (.bin)")]
    Extension,
    #[error("Strum parse Error")]
    Conversion(#[from] strum::ParseError),
    #[error("Failed to parse the version")]
    VersionParse(#[from] semver::Error),
}

pub fn get_files(
    root_path: &PathBuf,
    hostname: &str,
) -> Result<Vec<OTAConfiguration>, GetFilesError> {
    info!("Getting all files from path {}", root_path.display());
    let mut configs = Vec::new();
    let product_name = root_path
        .file_name()
        .ok_or(GetFilesError::Filename)?
        .to_string_lossy();
    let entries = fs::read_dir(root_path)?;

    for entry in entries.flatten() {
        info!("Reading entry: {entry:?}");
        let path = entry.path();
        if path.is_file() {
            info!("processing file: {}", path.display());
            // Splits the filename at the underscores. This is safe to do as names get sanitized on upload and are only uploaded by the pipeline
            let split_name: Vec<_> = path
                .file_name()
                .ok_or(GetFilesError::Filename)?
                .to_str()
                .ok_or(GetFilesError::Filename)?
                .split('_')
                .collect();
            let version = split_name[2]
                .strip_suffix(".bin")
                .ok_or(GetFilesError::Extension)?
                .replace('-', ".");
            debug!("Version: {:?}", version);
            debug!("split_name: {:?}", split_name);
            // TODO this is kinda messy
            let board_config = BoardConfig::from_str(split_name[1])?;
            let service = split_name[0];
            let board_type = BoardType::from_str(&product_name).unwrap();
            let version = if version.contains('.') {
                Version::parse(&version)?
            } else {
                // Handle simple version number by adding .0.0
                Version::parse(&format!("{}.0.0", version))?
            };
            let version_replaced = format!("{}-{}-{}", version.major, version.minor, version.patch);
            let fw_url =
                format!("{hostname}/{service}/{board_type}/{board_config}/{version_replaced}.bin");
            let cfg = OTAConfiguration {
                version,
                url: fw_url,
                board: Some(board_type),
                config: Some(board_config),
            };
            configs.push(cfg);
        } else if path.is_dir() {
            println!("Directory: {}", path.display());
        }
    }

    Ok(configs)
}

pub fn prune_files(path: &PathBuf, service: &Services, keep_last: usize) {
    let Ok(mut config_list) = get_files(path, "irrelevant") else {
        error!("failed to get file list for pruning");
        return
    };
    config_list.sort_by_key(|x| x.version.clone());
    config_list.truncate(config_list.len() - keep_last);
    for cfg in config_list {
        println!("{cfg:?}");
        let path = path.to_string_lossy();
        let board_type = cfg. config.unwrap();
        let path_to_remove = format!("{path}/{service}_{}_{}-{}-{}.bin", board_type, cfg.version.major, cfg.version.minor, cfg.version.patch);
        if let Err(e) = fs::remove_file(&path_to_remove) {
            error!("Failed to delete {path_to_remove}, {e:?}");
            return;
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_file_loading() {
        let expected_1 = OTAConfiguration {
            version: Version::parse("1.2.3").unwrap(),
            url: "example.com/firmware/waterlevel/INA233/1-2-3.bin".to_string(),
            board: Some(BoardType::Waterlevel),
            config: Some(BoardConfig::INA233),
        };
        let expected_2 = OTAConfiguration {
            version: Version::parse("4.5.6").unwrap(),
            url: "example.com/firmware/waterlevel/INA226/4-5-6.bin".to_string(),
            board: Some(BoardType::Waterlevel),
            config: Some(BoardConfig::INA226),
        };
        let loaded_configs = get_files(&PathBuf::from("./test/waterlevel"), "example.com").unwrap();

        assert_eq!(loaded_configs[1], expected_1);
        assert_eq!(loaded_configs[0], expected_2);
    }

    #[test]
    fn test_valid_mac_address_plain() {
        let mac_str = "001A2B3C4D5E";
        let expected = [0x00, 0x1A, 0x2B, 0x3C, 0x4D, 0x5E];
        assert_eq!(parse_mac_address(mac_str).unwrap(), expected);
    }

    #[test]
    fn test_valid_lowercase_mac_address() {
        let mac_str = "001a2b3c4d5e";
        let expected = [0x00, 0x1A, 0x2B, 0x3C, 0x4D, 0x5E];
        assert_eq!(parse_mac_address(mac_str).unwrap(), expected);
    }

    #[test]
    fn test_invalid_mac_address_wrong_length() {
        let mac_str = "001A2B3C4D";
        assert!(parse_mac_address(mac_str).is_err());
    }

    #[test]
    fn test_invalid_mac_address_invalid_characters() {
        let mac_str = "001A2B3C4DZZ";
        assert!(parse_mac_address(mac_str).is_err());
    }

    #[test]
    fn test_empty_mac_address() {
        let mac_str = "";
        assert!(parse_mac_address(mac_str).is_err());
    }

    #[test]
    fn test_mac_address_with_extra_spaces() {
        let mac_str = "001A2B3C 4D5E";
        assert!(parse_mac_address(mac_str).is_err());
    }
}