use clap::Parser;
use std::{
    fs,
    path::{Path, PathBuf},
};

use crate::{
    logging::{get_default_path as default_log_path, setup_logging},
    settings::{BackendType, Settings, settings_default_dir_path},
};

pub mod commands;
pub use commands::CliCommand;
pub use commands::PendingCliCommand;
use path_absolutize::Absolutize;

#[derive(Parser, Debug)]
#[command(author, version, about)]
pub struct Cli {
    /// Sets the entries Json file path and starts using it.
    #[arg(short, long, value_name = "FILE PATH")]
    #[cfg(feature = "json")]
    json_file_path: Option<PathBuf>,

    /// Sets the entries sqlite file path and starts using it.
    #[arg(short, long, value_name = "FILE PATH")]
    #[cfg(feature = "sqlite")]
    sqlite_file_path: Option<PathBuf>,

    /// Sets the backend type and starts using it.
    #[arg(short, long, value_enum)]
    backend_type: Option<BackendType>,

    #[arg(short = 'c', long = "config", value_name = "DIR PATH", help = config_help())]
    pub config_path: Option<PathBuf>,

    /// Increases logging verbosity each use for up to 3 times.
    #[arg(short = 'v', long, action = clap::ArgAction::Count)]
    verbose: u8,

    #[arg(short = 'l', long = "log", value_name = "FILE PATH", help = log_help())]
    log_file: Option<PathBuf>,

    #[command(subcommand)]
    pub command: Option<CliCommand>,
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum CliResult {
    Return,
    Continue,
    PendingCommand(PendingCliCommand),
}

impl Cli {
    pub async fn handle_cli(mut self, settings: &mut Settings) -> anyhow::Result<CliResult> {
        #[cfg(feature = "json")]
        if let Some(json_path) = self.json_file_path.take() {
            set_json_path(json_path, settings).await?;
            set_backend_type(BackendType::Json, settings);
        }

        #[cfg(feature = "sqlite")]
        if let Some(sql_path) = self.sqlite_file_path.take() {
            set_sqlite_path(sql_path, settings).await?;
            set_backend_type(BackendType::Sqlite, settings);
        }

        if let Some(backend) = self.backend_type.take() {
            set_backend_type(backend, settings);
        }

        setup_logging(self.verbose, self.log_file.take())?;

        if let Some(cmd) = self.command.take() {
            cmd.exec(settings, self.config_path.as_ref())
        } else {
            Ok(CliResult::Continue)
        }
    }
}

#[cfg(feature = "json")]
async fn set_json_path(path: PathBuf, settings: &mut Settings) -> anyhow::Result<()> {
    ensure_path_exists(&path).await?;

    settings.json_backend.file_path = path.absolutize().map(PathBuf::from).ok();

    Ok(())
}

async fn ensure_path_exists(path: &Path) -> anyhow::Result<()> {
    if path.exists() {
        return Ok(());
    }

    if let Some(parent) = path.parent() {
        fs::create_dir_all(parent)?;
    }

    Ok(())
}

#[cfg(feature = "sqlite")]
async fn set_sqlite_path(path: PathBuf, settings: &mut Settings) -> anyhow::Result<()> {
    ensure_path_exists(&path).await?;

    settings.sqlite_backend.file_path = path.absolutize().map(PathBuf::from).ok();

    Ok(())
}

#[inline]
fn set_backend_type(backend: BackendType, settings: &mut Settings) {
    settings.backend_type = Some(backend);
}

fn log_help() -> String {
    format!(
        "Specifies a file to use for logging\n(default file: {})",
        default_log_path()
            .map(|path| path.to_string_lossy().to_string())
            .unwrap_or_default()
    )
}

fn config_help() -> String {
    format!(
        "Specifies the path for the configuration directory.\n\
            The configuration directory is considered as the root for themes files too.\n\
            It still accepts the path for configuration file for backward compatibility.\n\
            (default path: {})",
        settings_default_dir_path()
            .map(|path| path.to_string_lossy().to_string())
            .unwrap_or_default()
    )
}

#[cfg(test)]
mod tests {
    use std::path::PathBuf;

    use clap::Parser;
    use tempfile::Builder;

    use super::*;

    #[test]
    fn parse_backend_and_config() {
        let cli = Cli::parse_from([
            "tjournal",
            "--backend-type",
            "json",
            "--config",
            "/tmp/config",
            "-vv",
            "assign-priority",
            "4",
        ]);

        assert_eq!(cli.backend_type, Some(BackendType::Json));
        assert_eq!(cli.config_path, Some(PathBuf::from("/tmp/config")));
        assert_eq!(cli.verbose, 2);
        assert_eq!(
            cli.command,
            Some(CliCommand::AssignPriority { priority: 4 })
        );
    }

    #[test]
    fn parse_rejects_bad_backend() {
        let err = Cli::try_parse_from(["tjournal", "--backend-type", "bogus"]).unwrap_err();

        assert!(err.to_string().contains("invalid value"));
    }

    #[tokio::test]
    async fn handle_cli_without_command() {
        let dir = Builder::new().prefix("cli-log").tempdir().unwrap();
        let mut settings = Settings::default();
        let cli = Cli::parse_from([
            "tjournal",
            "--log",
            dir.path().join("journal.log").to_str().unwrap(),
        ]);

        let result = cli.handle_cli(&mut settings).await.unwrap();

        assert_eq!(result, CliResult::Continue);
    }

    #[tokio::test]
    async fn ensure_path_creates_parent() {
        let dir = Builder::new().prefix("cli-parent").tempdir().unwrap();
        let file_path = dir.path().join("nested").join("entries.json");

        ensure_path_exists(&file_path).await.unwrap();

        assert!(file_path.parent().unwrap().exists());
    }

    #[cfg(feature = "json")]
    #[tokio::test]
    async fn set_json_path_absolutizes() {
        let dir = Builder::new().prefix("cli-json").tempdir().unwrap();
        let mut settings = Settings::default();
        let file_path = dir.path().join("entries.json");

        set_json_path(file_path.clone(), &mut settings)
            .await
            .unwrap();

        assert_eq!(
            settings.json_backend.file_path,
            Some(file_path.absolutize().unwrap().into_owned())
        );
    }

    #[cfg(feature = "sqlite")]
    #[tokio::test]
    async fn set_sqlite_path_absolutizes() {
        let dir = Builder::new().prefix("cli-sqlite").tempdir().unwrap();
        let mut settings = Settings::default();
        let file_path = dir.path().join("entries.db");

        set_sqlite_path(file_path.clone(), &mut settings)
            .await
            .unwrap();

        assert_eq!(
            settings.sqlite_backend.file_path,
            Some(file_path.absolutize().unwrap().into_owned())
        );
    }

    #[test]
    fn backend_type_sets_value() {
        let mut settings = Settings::default();

        set_backend_type(BackendType::default(), &mut settings);

        assert_eq!(settings.backend_type, Some(BackendType::default()));
    }
}
