use std::collections::HashMap;
use std::fs::File;
use std::io::{BufReader, BufWriter};
use std::path::PathBuf;
use serenity::model::prelude::*;
use crate::error::ManifoldResult;

#[derive(Debug)]
pub struct ManifoldConfig {
    config_path: PathBuf,
    config_environment: String,
    config: HashMap<String, String>
}

pub trait Config {
    fn load_config(&mut self) -> ManifoldResult<usize>;
    fn save_config(&self) -> ManifoldResult<usize>;
    fn create_default_config(&self, config_file: &String, config_environment: &String) -> ManifoldResult<usize>;
    fn get_environment(&self) -> &String;
    fn get_path(&self) -> &PathBuf;
    fn get_environment_mut(&mut self) -> &mut String;
    fn get_path_mut(&mut self) -> &mut PathBuf;
    fn get_value(&self, key: &String) -> Option<&String>;
    fn set_value(&mut self, key: &String, value: &String) -> Option<String>;
    fn unset_value(&mut self, key: &String) -> Option<String>;
    fn get_role(&self, role_name: &String) -> RoleId;
    fn get_channel(&self, channel_name: &String) -> ChannelId;
    fn get_message(&self, message_id: &String) -> MessageId;
}

impl ManifoldConfig {
    pub fn new() -> Self {
        ManifoldConfig {
            config_path: Default::default(),
            config_environment: "Production".to_string(),
            config: HashMap::<String, String>::new(),
        }
    }
}

impl Config for ManifoldConfig {
    fn load_config(&mut self) -> ManifoldResult<usize> {
        let file = File::open(&self.config_path).expect("Could not open config file. Please check and retry.");
        let reader = BufReader::new(file);
        self.config = serde_json::from_reader(reader)
            .map_err(|e| {error!("Error reading config as JSON: {:?}", e.to_string()); e} )?;

        let config_entry_count = self.config.len();

        debug!("Loaded config: {:?}", &self.config);
        debug!("Loaded {} entries", config_entry_count);

        Ok(config_entry_count)
    }

    fn save_config(&self) -> ManifoldResult<usize> {
        let file = File::create(&self.config_path).expect("Could not open config file for saving.");
        let writer = BufWriter::new(file);
        serde_json::to_writer(writer, &self.config)?;

        let config_entry_count = self.config.len();

        Ok(config_entry_count)
    }

    fn create_default_config(&self, config_file: &String, config_environment: &String) -> ManifoldResult<usize> {
        let mut config = ManifoldConfig::new();
        config.config_environment = config_environment.to_owned();
        config.config_path = PathBuf::from(config_file);
        config.config.insert(format!("{}LogChannel", config_environment), "".to_string());
        config.config.insert(format!("{}BotOwner", config_environment), "".to_string());
        config.config.insert(format!("{}AdminRole", config_environment), "".to_string());
        config.config.insert(format!("{}DJRole", config_environment), "".to_string());
        config.config.insert(format!("{}SpamChannel", config_environment), "true".to_string());
        config.config.insert(format!("{}ResponsesFilePath", config_environment), "config/responses.txt".to_string());

        config.save_config()
    }

    fn get_environment(&self) -> &String {
        &self.config_environment
    }

    fn get_path(&self) -> &PathBuf {
        &self.config_path
    }

    fn get_environment_mut(&mut self) -> &mut String {
        &mut self.config_environment
    }

    fn get_path_mut(&mut self) -> &mut PathBuf {
        &mut self.config_path
    }

    fn get_value(&self, key: &String) -> Option<&String> {
        self.config.get(&format!("{}{}", &self.config_environment, key))
    }

    fn set_value(&mut self, key: &String, value: &String) -> Option<String> {
        self.config.insert(format!("{}{}", &self.config_environment, key), value.clone())
    }

    fn unset_value(&mut self, key: &String) -> Option<String> {
        self.config.remove(&*format!("{}{}", &self.config_environment, key))
    }

    fn get_role(&self, role_name: &String) -> RoleId {
        let key = format!("{}Role", role_name);

        RoleId(self.get_value(&key).unwrap().parse::<u64>().unwrap())
    }

    fn get_channel(&self, channel_name: &String) -> ChannelId {
        let key = format!("{}Channel", channel_name);

        ChannelId(self.get_value(&key).unwrap().parse::<u64>().unwrap())
    }

    fn get_message(&self, message_id: &String) -> MessageId {
        let key = format!("{}Message", message_id);

        MessageId(self.get_value(&key).unwrap().parse::<u64>().unwrap())
    }
}