use std::path::PathBuf;

use clap::parser::ValuesRef;
use clap::{value_parser, Arg, ArgAction, ArgMatches, Command};
use log::{debug, error, info};
use rusqlite::Connection;
use serde::Serialize;
use simple_logger::SimpleLogger;

use db::securities::list_securities;

use crate::db::users::{create_user, list_users};
use crate::migration::apply_migrations;
use crate::util::{CustomResult, Error};
use crate::webui::web_ui_main;

mod db;
mod event_processor;
mod migration;
mod services;
mod util;
mod webui;
mod events;

#[derive(Debug, Serialize)]
struct Output<T> {
    status: String,
    result: T,
}

impl<T> Output<T> {
    fn success(shit: T) -> Output<T> {
        return Output {
            status: "success".to_string(),
            result: shit,
        };
    }
}

trait CommandLineUserLogic {
    fn create_user(
        &mut self,
        conn: &mut Connection,
        name: &String,
        public_key: &String,
    ) -> CustomResult<()>;

    fn list_user(&mut self, conn: &Connection) -> CustomResult<()>;

    fn list_securities(&mut self, conn: &Connection) -> CustomResult<()>;

    fn process_events(
        &mut self,
        conn: &mut Connection,
        files: ValuesRef<PathBuf>,
    ) -> CustomResult<()>;

    fn run_webui(
        &mut self,
        conn: &mut Connection,
        port: u16,
        enable_template_autoreload: bool,
    ) -> CustomResult<()>;
}

fn verbosity_arg() -> Arg {
    return Arg::new("verbosity")
        .short('v')
        .action(ArgAction::Count)
        .default_value("0");
}

fn get_verbosity(m: &ArgMatches) -> log::LevelFilter {
    match m.get_one::<u8>("verbosity") {
        None => log::LevelFilter::Error,
        Some(1) => log::LevelFilter::Warn,
        Some(2) => log::LevelFilter::Info,
        Some(3) => log::LevelFilter::Debug,
        Some(4) => log::LevelFilter::Trace,
        _ => log::LevelFilter::Error,
    }
}

fn db_path_arg() -> Arg {
    return Arg::new("db-path")
        .long("db-path")
        .value_name("FILE")
        .value_parser(value_parser!(PathBuf))
        .default_value("ledger.sqlite");
}

fn get_db_path(m: &ArgMatches) -> &PathBuf {
    return m.get_one::<PathBuf>("db-path").unwrap();
}

fn new_user_command_line_parser() -> Command {
    return Command::new("new")
        .long_flag("new")
        .about("Create new user.")
        .arg(
            Arg::new("name")
                .long("name")
                .required(true)
                .help("name of new user.")
                .action(ArgAction::Set),
        )
        .arg(
            Arg::new("public_key")
                .required(true)
                .long("public-key")
                .help("public key of users.")
                .action(ArgAction::Set),
        );
}

fn ls_user_command_line_parser() -> Command {
    return Command::new("ls").long_flag("ls").about("List all users.");
}

fn process_events_command_line_parser() -> Command {
    Command::new("process")
        .about("Process events one after the other.  In the order received")
        .arg_required_else_help(true)
        .arg(clap::arg!(<PATH> ... "Stuff to add").value_parser(value_parser!(PathBuf)))
}

fn user_command_line_parser() -> Command {
    return Command::new("users")
        .about("Handy command about users.")
        .subcommand(new_user_command_line_parser())
        .subcommand(ls_user_command_line_parser())
        .arg_required_else_help(true);
}

fn event_command_line_parser() -> Command {
    return Command::new("events")
        .about("Process and query events files")
        .subcommand(process_events_command_line_parser())
        .arg_required_else_help(true);
}

fn ls_securities_command_line_parser() -> Command {
    return Command::new("ls")
        .long_flag("ls")
        .about("List all securities.");
}

fn run_web_ui_command_line_parser() -> Command {
    return Command::new("run")
        .arg(
            Arg::new("port")
                .long("port")
                .value_parser(clap::value_parser!(u16).range(2000..))
                .action(ArgAction::Set)
                .default_value("2222"),
        )
        .arg(
            Arg::new("enable-template-autoreload")
                .long("enable-template-autoreload")
                .required(false)
                .num_args(0)
                .help("Reload underlying template (for development)"),
        )
        .about("Run web user interface.");
}

fn securities_command_line_parser() -> Command {
    return Command::new("securities")
        .about("Handy command about securities.")
        .subcommand(ls_securities_command_line_parser())
        .arg_required_else_help(true);
}

fn web_ui_command_line_parser() -> Command {
    return Command::new("wui")
        .about("Web user interface.")
        .subcommand(run_web_ui_command_line_parser())
        .arg_required_else_help(true);
}

fn command_line_parser() -> Command {
    return Command::new("prog")
        .arg(verbosity_arg())
        .arg(db_path_arg())
        .subcommand(event_command_line_parser())
        .subcommand(user_command_line_parser())
        .subcommand(securities_command_line_parser())
        .subcommand(web_ui_command_line_parser())
        .arg_required_else_help(true);
}

fn process_new_user_command_line(
    conn: &mut Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing new user command line {:?}.", m);
    let name = m.get_one::<String>("name").unwrap();
    let pk = m.get_one::<String>("public_key").unwrap();
    logic.create_user(conn, name, pk)
}

fn process_list_user_command_line(
    conn: &Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing list users command line {:?}.", m);
    logic.list_user(conn)
}

fn process_user_command_line(
    conn: &mut Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing user command line {:?}.", m);
    match m.subcommand() {
        Some(("new", new_user_match)) => process_new_user_command_line(conn, new_user_match, logic),
        Some(("ls", list_user_match)) => {
            process_list_user_command_line(conn, list_user_match, logic)
        }
        _ => unreachable!(),
    }
}

fn process_list_securities_command_line(
    conn: &Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing list securities command line {:?}.", m);
    logic.list_securities(conn)
}

fn process_process_events_command_line(
    conn: &mut Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing process event command line {:?}.", m);
    let mut files = m.get_many::<PathBuf>("PATH").unwrap();
    if files.any(|x| !x.exists()) {
        error!("Some passed files do not exists.  Existing right now.");
        return Err(Error::UserInputError(
            "Some passed files do not exists.  Existing right now.".to_string(),
        ));
    }

    logic.process_events(conn, files)
}

fn process_run_wui_command_line(
    conn: &mut Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing run wui command line {:?}.", m);
    let port = m.get_one::<u16>("port").unwrap_or(&2222);
    let enable_template_autoreload = m.get_flag("enable-template-autoreload");
    logic.run_webui(conn, *port, enable_template_autoreload)
}

fn process_securities_command_line(
    conn: &Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing securities command line {:?}.", m);
    match m.subcommand() {
        Some(("ls", list_securities_match)) => {
            process_list_securities_command_line(conn, list_securities_match, logic)
        }
        _ => unreachable!(),
    }
}

fn process_events_command_line(
    conn: &mut Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing events command line {:?}.", m);
    match m.subcommand() {
        Some(("process", process_events_match)) => {
            process_process_events_command_line(conn, process_events_match, logic)
        }
        _ => unreachable!(),
    }
}

fn process_wui_command_line(
    conn: &mut Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing wui command line {:?}.", m);
    match m.subcommand() {
        Some(("run", run_wui_match)) => process_run_wui_command_line(conn, run_wui_match, logic),
        _ => unreachable!(),
    }
}

fn process_command_line(
    conn: &mut Connection,
    m: &ArgMatches,
    logic: &mut dyn CommandLineUserLogic,
) -> CustomResult<()> {
    debug!("Processing command line {:?}.", m);
    match m.subcommand() {
        Some(("users", user_match)) => process_user_command_line(conn, user_match, logic),
        Some(("securities", securities_match)) => {
            process_securities_command_line(conn, securities_match, logic)
        }
        Some(("events", events_match)) => process_events_command_line(conn, events_match, logic),
        Some(("wui", wui_match)) => process_wui_command_line(conn, wui_match, logic),
        _ => {
            println!("Received un parsable command. {:?}", m.subcommand());
            unreachable!();
        }
    }
}

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

    struct TestCommandLineLogic {
        list_user_count: usize,
        create_user_count: usize,
        list_securities_count: usize,
        process_events_count: usize,
        run_webui_count: usize,
    }

    impl TestCommandLineLogic {
        fn new() -> TestCommandLineLogic {
            return TestCommandLineLogic {
                list_user_count: 0,
                create_user_count: 0,
                list_securities_count: 0,
                process_events_count: 0,
                run_webui_count: 0,
            };
        }
    }

    impl CommandLineUserLogic for TestCommandLineLogic {
        fn create_user(
            &mut self,
            _conn: &mut Connection,
            _name: &String,
            _public_key: &String,
        ) -> CustomResult<()> {
            self.create_user_count += 1;
            Ok(())
        }

        fn list_user(&mut self, _conn: &Connection) -> CustomResult<()> {
            self.list_user_count += 1;
            Ok(())
        }

        fn list_securities(&mut self, _conn: &Connection) -> CustomResult<()> {
            self.list_securities_count += 1;
            Ok(())
        }

        fn process_events(
            &mut self,
            _conn: &mut Connection,
            _files: ValuesRef<PathBuf>,
        ) -> CustomResult<()> {
            self.process_events_count += 1;
            Ok(())
        }

        fn run_webui(
            &mut self,
            _conn: &mut Connection,
            _port: u16,
            _enable_template_autoreload: bool,
        ) -> CustomResult<()> {
            self.run_webui_count += 1;
            Ok(())
        }
    }

    #[test]
    fn verbosity() {
        {
            let cmd = Command::new("test").arg(verbosity_arg());
            let m = cmd.get_matches_from(vec!["test", "-vv"]);
            assert_eq!(get_verbosity(&m), log::LevelFilter::Info);
        }

        {
            let cmd = Command::new("test").arg(verbosity_arg());
            let m = cmd.get_matches_from(vec!["test"]);
            assert_eq!(get_verbosity(&m), log::LevelFilter::Error);
        }
    }

    #[test]
    fn db_path() {
        {
            let cmd = Command::new("test").arg(db_path_arg());
            let m = cmd.get_matches_from(vec!["test", "--db-path", "/foo/bar"]);
            let expt = PathBuf::from("/foo/bar");
            assert_eq!(get_db_path(&m), &expt);
        }

        {
            let cmd = Command::new("test").arg(db_path_arg());
            let m = cmd.get_matches_from(vec!["test"]);
            let expt = PathBuf::from("ledger.sqlite");
            assert_eq!(get_db_path(&m), &expt);
        }
    }

    #[test]
    fn create_user() {
        let cmd = command_line_parser();
        let m = cmd.get_matches_from(vec![
            "test",
            "users",
            "new",
            "--name",
            "paul",
            "--public-key",
            "123abc",
        ]);
        let mut logic = TestCommandLineLogic::new();
        let mut conn = Connection::open_in_memory().unwrap();
        process_command_line(&mut conn, &m, &mut logic);
        assert_eq!(logic.create_user_count, 1);
    }

    #[test]
    fn list_users() {
        let cmd = command_line_parser();
        let m = cmd.get_matches_from(vec!["test", "users", "ls"]);
        let mut logic = TestCommandLineLogic::new();
        let mut conn = Connection::open_in_memory().unwrap();
        process_command_line(&mut conn, &m, &mut logic);
        assert_eq!(logic.list_user_count, 1);
    }

    #[test]
    fn list_securities() {
        let cmd = command_line_parser();
        let m = cmd.get_matches_from(vec!["test", "securities", "ls"]);
        let mut logic = TestCommandLineLogic::new();
        let mut conn = Connection::open_in_memory().unwrap();
        process_command_line(&mut conn, &m, &mut logic);
        assert_eq!(logic.list_securities_count, 1);
    }

    #[test]
    fn process_events() {
        let cmd = command_line_parser();
        let m = cmd.get_matches_from(vec!["test", "events", "process", "/dev/null"]);
        let mut logic = TestCommandLineLogic::new();
        let mut conn = Connection::open_in_memory().unwrap();
        process_command_line(&mut conn, &m, &mut logic);
        assert_eq!(logic.process_events_count, 1);
    }

    #[test]
    fn run_web_ui() {
        let cmd = command_line_parser();
        let m = cmd.get_matches_from(vec!["test", "wui", "run"]);
        let mut logic = TestCommandLineLogic::new();
        let mut conn = Connection::open_in_memory().unwrap();
        process_command_line(&mut conn, &m, &mut logic);
        assert_eq!(logic.run_webui_count, 1);
    }
}

struct ProCommandLineLogic {}

impl ProCommandLineLogic {
    fn new() -> ProCommandLineLogic {
        return ProCommandLineLogic {};
    }
}

impl CommandLineUserLogic for ProCommandLineLogic {
    fn create_user(
        &mut self,
        conn: &mut Connection,
        name: &String,
        public_key: &String,
    ) -> CustomResult<()> {
        let tx = conn.transaction().map_err(Error::SqlError)?;
        create_user(&tx, name, public_key)?;
        tx.commit().map_err(Error::SqlError)
    }

    fn list_user(&mut self, conn: &Connection) -> CustomResult<()> {
        let users = list_users(conn)?;
        let out = Output::success(users);
        println!("{}", serde_json::to_string(&out).unwrap());
        Ok(())
    }

    fn list_securities(&mut self, conn: &Connection) -> CustomResult<()> {
        let securities = list_securities(conn)?;
        let out = Output::success(securities);
        println!("{}", serde_json::to_string(&out).unwrap());
        Ok(())
    }

    fn process_events(
        &mut self,
        conn: &mut Connection,
        files: ValuesRef<PathBuf>,
    ) -> CustomResult<()> {
        // process_event_files(conn, files)
        Ok(())
    }

    fn run_webui(
        &mut self,
        conn: &mut Connection,
        port: u16,
        enable_template_autoreload: bool,
    ) -> CustomResult<()> {
        info!("Serving web-ui on port {:?}", port);
        web_ui_main(conn, port, enable_template_autoreload)
    }
}

fn get_connection(m: &ArgMatches) -> Connection {
    let path = get_db_path(&m);
    info!("Sqlite database location is {:?}.", path);
    return Connection::open(path).unwrap();
}

fn set_logger(m: &ArgMatches) {
    SimpleLogger::new()
        .with_level(get_verbosity(&m))
        .init()
        .unwrap();
}

fn main() {
    let command = command_line_parser();
    let m = command.get_matches();

    set_logger(&m);
    let mut conn = get_connection(&m);

    apply_migrations(&mut conn).unwrap();
    let mut logic = ProCommandLineLogic::new();
    process_command_line(&mut conn, &m, &mut logic);
}