use clap::{ArgMatches, Command};
use mize::item::ItemData;
use std::{collections::HashMap, ffi::OsString};
use mize::prelude::*;

#[unsafe(no_mangle)]
pub extern "C" fn part_cli() -> MizeResult<()> {
  
  include_native!("Command", clap::Command, {
      associated: [new(name: String)],
      //methods: [arg(arg: clap::Arg), subcommand(cmd: clap::Command)]
  });
  
  opt("state")
    .fun(Box::new(|| {
      let mize = get_global_mize().unwrap();
      let state = CliPartState {
          cmds: HashMap::new(),
          current_cmd_name: "marts-cli".to_string(),
          actions: HashMap::new(),
          parsers: Some(Vec::new()),
          mize: mize.clone(),
      };
      Ok(ItemData::from_native(state)?)
    }));
  
  
  method("set_command", |args| {
    let mut state = get_config("self.state")?.native_mut::<CliPartState>()?;
    let cmd = args.get_path("0")?.native::<String>()?;
    state.current_cmd_name = cmd.to_owned();
    if !state.cmds.contains_key(&*cmd) {
        state.cmds
            .insert((*cmd).to_owned(), Command::new((*cmd).to_owned()));
    }
    Ok(ItemData::new())
  });
  
  method("subcommand", |args| {
    let mut state = get_config("self.state")?.native_mut::<CliPartState>()?;
    let subcmd = args.get_path("0")?.native_take::<clap::Command>()?;
    let action = args.get_path("1")?;
    let name = subcmd.get_name().to_string();
    let cur_cmd_name = state.current_cmd_name.clone();
    let cmd = state
        .cmds
        .remove(&cur_cmd_name)
        .unwrap()
        .subcommand(subcmd);
    state.cmds.insert(cur_cmd_name.clone(), cmd);
    state.actions.insert(name, action);
    Ok(ItemData::new())
  });

  method("run", |args| {
    let cmdline = args.get_path("0")?.native_take::<Vec<String>>()?;
    let mut state = get_config("self.state")?.native_mut::<CliPartState>()?;
    let cmd_name = cmdline.iter().nth(0).ok_or(mize_err!("empty cmdline"))?;
    let cmd = state.cmds.remove(cmd_name).ok_or(mize_err!("cmd {} not found in CliPart", cmd_name))?;

    let matches = cmd.get_matches_from(cmdline);
    let sub_name = matches.subcommand_name().ok_or(mize_err!("subcommand not found"))?;
    let sub_matches = matches.subcommand_matches(sub_name).ok_or(mize_err!("subcommand matches not found"))?;
    let action = state.actions.remove(sub_name).ok_or(mize_err!("action for subcommand not found"))?;
    let mut args = ItemData::new();
    args.set_path("0", ItemData::from_native(sub_matches.clone())?);
    action.call(args)?;
    
    Ok(ItemData::new())
  });

  // TODO in future....
  // Register methods from the impl block
  //CliPartState::methods_from_impl()?;
  
  Ok(())
}

pub struct CliPartState {
    cmds: HashMap<String, Command>,
    current_cmd_name: String,
    actions:
        HashMap<String, ItemData>,
    parsers: Option<Vec<Box<dyn Fn(Mize, Vec<String>) -> MizeResult<()> + Send + Sync + 'static>>>,
    mize: Mize,
}


/*
#[part_impl]
impl CliPartState {
    pub fn set_command(&mut self, cmd: &str) {
        self.current_cmd_name = cmd.to_owned();
        if !self.cmds.contains_key(cmd) {
            self.cmds
                .insert(cmd.to_owned(), Command::new(cmd.to_owned()));
        }
    }
    pub fn subcommand(
        &mut self,
        subcmd: Command,
        action: Box<dyn Fn(&ArgMatches, Mize) -> MizeResult<()> + Send + Sync + 'static>,
    ) -> MizeResult<()> {
        let name = subcmd.get_name().to_string();
        let cmd = self
            .cmds
            .remove(&self.current_cmd_name)
            .unwrap()
            .subcommand(subcmd);
        self.cmds.insert(self.current_cmd_name.clone(), cmd);
        self.actions.insert(name, action);
        Ok(())
    }
    
    /*
    pub fn add_sub_parser<T: Fn(Mize, Vec<String>) -> MizeResult<()> + Send + Sync + 'static>(
        &mut self,
        parser: T,
    ) -> MizeResult<()> {
        self.parsers.as_mut().unwrap().push(Box::new(parser));
        Ok(())
    } 
    */
    
    pub fn with_cmd(
        &mut self,
        func: fn(cmd: Command) -> MizeResult<Command>,
    ) -> MizeResult<()> {
        let cmd = self.cmds.remove(&self.current_cmd_name).ok_or(mize_err!(
            "current command {} not found",
            self.current_cmd_name
        ))?;
        let cmd = func(cmd)?;
        self.cmds.insert(self.current_cmd_name.clone(), cmd);
        Ok(())
    }
    pub fn run(&mut self, cmdline: Vec<String>) -> MizeResult<()> {
      let cmd_name = cmdline.iter().nth(0).ok_or(mize_err!("empty cmdline"))?;
      let cmd = self.cmds.remove(cmd_name).ok_or(mize_err!("cmd {} not found in CliPart", cmd_name))?;

      let matches = cmd.get_matches_from(cmdline);
      let sub_name = matches.subcommand_name().ok_or(mize_err!("subcommand not found"))?;
      let sub_matches = matches.subcommand_matches(sub_name).ok_or(mize_err!("subcommand matches not found"))?;
      let action = self.actions.remove(sub_name).ok_or(mize_err!("action for subcommand not found"))?;
      action(sub_matches, self.mize.clone())?;
      
      Ok(())
    }
}
*/