use std::{
    io::Read,
    ops::Deref,
    path::{Path, PathBuf},
    sync::{Arc, Mutex},
};

use clap::{Parser, Subcommand};
use cuddle_please_frontend::{gatheres::ConfigArgs, PleaseConfig, PleaseConfigBuilder};
use cuddle_please_misc::{
    ConsoleUi, DynRemoteGitClient, DynUi, GiteaClient, GlobalArgs, LocalGitClient, StdinFn,
    VcsClient,
};

use crate::{
    config_command::{ConfigCommand, ConfigCommandHandler},
    doctor_command::DoctorCommandHandler,
    gitea_command::{GiteaCommand, GiteaCommandHandler},
    release_command::ReleaseCommandHandler,
};

#[derive(Parser)]
#[command(author, version, about, long_about = None)]
pub struct Command {
    #[command(flatten)]
    global: GlobalArgs,

    #[command(flatten)]
    config: ConfigArgs,

    #[command(subcommand)]
    commands: Option<Commands>,

    #[clap(skip)]
    ui: DynUi,

    #[clap(skip)]
    stdin: StdinFn,
}

impl Default for Command {
    fn default() -> Self {
        Self::new()
    }
}

impl Command {
    pub fn new() -> Self {
        let args = std::env::args();

        Self::new_from_args_with_stdin(Some(ConsoleUi::default()), args, || {
            let mut input = String::new();
            std::io::stdin().read_to_string(&mut input)?;
            Ok(input)
        })
    }

    pub fn new_from_args<I, T, UIF>(ui: Option<UIF>, i: I) -> Self
    where
        I: IntoIterator<Item = T>,
        T: Into<std::ffi::OsString> + Clone,
        UIF: Into<DynUi>,
    {
        let mut s = Self::parse_from(i);

        if let Some(ui) = ui {
            s.ui = ui.into();
        }

        s
    }

    pub fn new_from_args_with_stdin<I, T, F, UIF>(ui: Option<UIF>, i: I, input: F) -> Self
    where
        I: IntoIterator<Item = T>,
        T: Into<std::ffi::OsString> + Clone,
        F: Fn() -> anyhow::Result<String> + Send + Sync + 'static,
        UIF: Into<DynUi>,
    {
        let mut s = Self::parse_from(i);

        if let Some(ui) = ui {
            s.ui = ui.into();
        }
        s.stdin = Some(Arc::new(Mutex::new(input)));

        s
    }

    pub fn execute(self, current_dir: Option<&Path>) -> anyhow::Result<()> {
        let config = self.build_config(current_dir)?;
        let git_client = self.get_git(config.get_source())?;
        let gitea_client = self.get_gitea_client();

        match &self.commands {
            Some(Commands::Release {}) => {
                ReleaseCommandHandler::new(config, git_client, gitea_client)
                    .execute(self.global.dry_run)?;
            }
            Some(Commands::Config { command }) => {
                ConfigCommandHandler::new(self.ui, config).execute(command)?;
            }
            Some(Commands::Gitea { command }) => {
                GiteaCommandHandler::new(self.ui, config, gitea_client)
                    .execute(command, self.global.token.expect("token to be set").deref())?;
            }
            Some(Commands::Doctor {}) => {
                DoctorCommandHandler::new(self.ui).execute()?;
            }
            None => {}
        }

        Ok(())
    }

    fn build_config(&self, current_dir: Option<&Path>) -> Result<PleaseConfig, anyhow::Error> {
        let mut builder = &mut PleaseConfigBuilder::new();
        if self.global.config_stdin {
            if let Some(stdin_fn) = self.stdin.clone() {
                let output = (stdin_fn.lock().unwrap().deref())();
                builder = builder.with_stdin(output?);
            }
        }
        let current_dir = get_current_path(current_dir, self.config.source.clone())?;
        let config = builder
            .with_config_file(&current_dir)
            .with_source(&current_dir)
            .with_execution_env(std::env::vars())
            .with_cli(self.config.clone())
            .build()?;
        Ok(config)
    }

    fn get_git(&self, current_dir: &Path) -> anyhow::Result<VcsClient> {
        if self.global.no_vcs {
            Ok(VcsClient::new_noop())
        } else {
            VcsClient::new_git(current_dir)
        }
    }

    fn get_gitea_client(&self) -> DynRemoteGitClient {
        match self.global.engine {
            cuddle_please_misc::RemoteEngine::Local => Box::new(LocalGitClient::new()),
            cuddle_please_misc::RemoteEngine::Gitea => Box::new(GiteaClient::new(
                &self.config.api_url.clone().expect("api_url to be set"),
                self.global.token.as_deref(),
            )),
        }
    }
}

#[derive(Debug, Clone, Subcommand)]
pub enum Commands {
    /// Config is mostly used for debugging the final config output
    Release {},

    #[command(hide = true)]
    Config {
        #[command(subcommand)]
        command: ConfigCommand,
    },

    #[command(hide = true)]
    Gitea {
        #[command(subcommand)]
        command: GiteaCommand,
    },
    /// Helps you identify missing things from your execution environment for cuddle-please to function as intended
    Doctor {},
}

fn get_current_path(
    optional_current_dir: Option<&Path>,
    optional_source_path: Option<PathBuf>,
) -> anyhow::Result<PathBuf> {
    let path = optional_source_path
        .or_else(|| optional_current_dir.map(|p| p.to_path_buf())) // fall back on current env from environment
        .filter(|v| v.to_string_lossy() != "") // make sure we don't get empty values
        //.and_then(|p| p.canonicalize().ok()) // Make sure we get the absolute path
        //.context("could not find current dir, pass --source as a replacement")?;
        .unwrap_or(PathBuf::from("."));

    if !path.exists() {
        anyhow::bail!("path doesn't exist {}", path.display());
    }

    Ok(path)
}