//! Configuration file that handles (de-)serializing other components

use std::{fs::{self, DirEntry}, io::Write, path::{Path, PathBuf}};
use serde::{Deserialize, Serialize};

use crate::{SquadObject, account::Account, error::Error, quest::Quest};

/// Struct for containing paths to other (de-)serializable things
#[derive(Serialize, Deserialize)]
#[serde(default)]
pub struct Config {
    /// Path to config directory
    #[serde(skip)]
    pub path: PathBuf,

    /// Path to serialized [quests][`crate::quest::Quest`] folder
    pub quests_path: PathBuf,
    
    /// Path to serialized [accounts][`crate::account::Account`] folder
    pub accounts_path: PathBuf,
    
    /// Path to serialized [map][`crate::map::Map`] file
    pub map: PathBuf,

    /// If true, print to std{out/err}
    pub verbose: bool,
}

impl Default for Config {
    fn default() -> Self {
        Config {
            path: ".".into(),
            quests_path: "quests".into(),
            accounts_path: "accounts".into(),
            map: "map.toml".into(),
            verbose: true,
        }
    }
}

fn handle_quest_entry(quest_entry: DirEntry) -> Result<Quest, Error>{
    let filetype = quest_entry.file_type();
    if let Err(error) = filetype {
        return Err(Error::IoError(error));
    }
    
    let path = quest_entry.path();

    let filetype = filetype.unwrap();
    if !filetype.is_file() {
        return Err(Error::IsNotAFile(path));
    }

    Quest::load(path)
}

fn handle_account_entry(account_entry: DirEntry) -> Result<Account, Error>{
    let filetype = account_entry.file_type();
    if let Err(error) = filetype {
        return Err(Error::IoError(error));
    }
    
    let path = account_entry.path();

    let filetype = filetype.unwrap();
    if !filetype.is_file() {
        return Err(Error::IsNotAFile(path));
    }

    Account::load(path)
}

impl Config {
    /// Deserialize config from TOML.
    ///
    /// This function wraps [try_load][Config::try_load].
    ///
    /// Logs all errors if `config.verbose == true`.
    /// Returns default config on error.
    ///
    /// # Examples
    /// ```rust
    /// use squad_quest::config::Config;
    ///
    /// let path = "cfg/config.toml".into();
    /// let config = Config::load(path);
    /// ```
    pub fn load(path: PathBuf) -> Self {
        let dir = path.parent()
            .unwrap_or(Path::new("."))
            .to_owned();

        match Self::try_load(path) {
            Ok(conf) => {
                if conf.verbose {
                    println!("Successfully loaded config");
                }
                conf
            },
            Err(error) => {
                let conf = Config {
                    path: dir,
                    ..Default::default()
                };
                
                if conf.verbose {
                    println!("Error while loading config: {error}");
                }
                
                conf
            }
        }
    }
    
    /// Serialize config into TOML.
    /// Config will be saved as `path/config.toml`
    ///
    /// # Examples
    /// ```rust
    /// use squad_quest::config::Config;
    ///
    /// let path = "cfg".into();
    ///
    /// let config = Config::default();
    ///
    /// if let Err(error) = config.save(path) {
    ///     // handle error
    /// }
    /// ```
    pub fn save(&self, path: PathBuf) -> Result<(), Error> {
        let mut path = path;
        path.push("config.toml");
        
        let str = match toml::to_string_pretty(&self) {
            Ok(string) => string,
            Err(error) => return Err(Error::TomlSerializeError(error)),
        };

        let mut file = match fs::File::create(path) {
            Ok(f) => f,
            Err(error) => return Err(Error::IoError(error)),
        };

        if let Err(error) = file.write_all(str.as_bytes()) {
            return Err(Error::IoError(error));
        }

        Ok(())
    }

    /// Deserialize config from TOML
    /// 
    /// # Examples
    /// ```rust
    /// use squad_quest::{config::Config,error::Error};
    /// # fn main() {
    /// # let _ = wrapper();
    /// # }
    /// # fn wrapper() -> Result<(), Error> {
    /// let path = "cfg/config.toml".into();
    /// let config = Config::try_load(path)?;
    /// # Ok(())
    /// # }
    /// ```
    pub fn try_load(path: PathBuf) -> Result<Self, Error> {
        let dir = path.parent()
            .unwrap_or(Path::new("."))
            .to_owned();

        match fs::read_to_string(path) {
            Ok(string) => {
                match toml::from_str::<Config>(&string) {
                    Ok(mut conf) => {
                        conf.path = dir;
                        Ok(conf)
                    },
                    Err(error) => {
                        Err(Error::TomlDeserializeError(error))
                    }
                }
            },
            Err(error) => {
                Err(Error::IoError(error))
            }
        }
    }

    /// Returns full path to quests folder
    /// This path will be relative to $PWD, not to config.
    ///
    /// # Examples
    /// ```rust
    /// use squad_quest::config::Config;
    ///
    /// let path = "cfg/config.toml".into();
    /// let config = Config::load(path);
    /// 
    /// let quests_path = config.full_quests_path();
    /// ```
    pub fn full_quests_path(&self) -> PathBuf {
        let mut path = self.path.clone();
        path.push(self.quests_path.clone());
        path
    }

    /// Load [Vec]<[Quest]> from quests folder.
    /// Also logs errors and counts successfully loaded quests.
    ///
    /// # Examples
    /// ```rust
    /// use squad_quest::{config::Config, quest::Quest};
    ///
    ///
    /// let path = "cfg/config.toml".into();
    /// let config = Config::load(path);
    /// let quests = config.load_quests();
    ///
    /// for quest in quests {
    ///     println!("Quest #{} {}", quest.id, quest.name);
    /// }
    /// ```
    pub fn load_quests(&self) -> Vec<Quest> {
        let mut out_vec = Vec::new();
        
        let path = self.full_quests_path();

        match fs::read_dir(path) {
            Ok(iter) => {
                for entry in iter {
                    match entry {
                        Ok(quest_entry) => {
                            match handle_quest_entry(quest_entry) {
                                Ok(quest) => out_vec.push(quest),
                                Err(error) if self.verbose => {
                                    eprintln!("Error on loading single quest: {error}");
                                },
                                _ => {},
                            }
                        },
                        Err(error) if self.verbose => {
                            eprintln!("Error on loading single quest: {error}");
                        },
                        _ => {},
                    }
                }
            },
            Err(error) if self.verbose => {
                eprintln!("Error on loading quests: {error}");
            },
            _ => {},
        }
        
        if self.verbose {
            println!("Loaded {} quests successfully", out_vec.len());
        }

        out_vec
    }

    /// Returns full path to accounts folder
    /// This path will be relative to $PWD, not to config.
    ///
    /// # Examples
    /// ```rust
    /// use squad_quest::config::Config;
    ///
    /// let path = "cfg/config.toml".into();
    /// let config = Config::load(path);
    /// 
    /// let accounts_path = config.full_accounts_path();
    /// ```
    pub fn full_accounts_path(&self) -> PathBuf {
        let mut path = self.path.clone();
        path.push(self.accounts_path.clone());
        path
    }

    /// Load [Vec]<[Account]> from accounts folder.
    /// Also logs errors and counts successfully loaded quests.
    ///
    /// # Examples
    /// ```rust
    /// use squad_quest::{config::Config, account::Account};
    ///
    ///
    /// let path = "cfg/config.toml".into();
    /// let config = Config::load(path);
    /// let accounts = config.load_accounts();
    ///
    /// for account in accounts {
    ///     println!("Account {}", account.id);
    /// }
    /// ```
    pub fn load_accounts(&self) -> Vec<Account> {
        let mut out_vec = Vec::new();
        
        let path = self.full_accounts_path();

        match fs::read_dir(path) {
            Ok(iter) => {
                for entry in iter {
                    match entry {
                        Ok(acc_entry) => {
                            match handle_account_entry(acc_entry) {
                                Ok(quest) => out_vec.push(quest),
                                Err(error) if self.verbose => {
                                    eprintln!("Error on loading single account: {error}");
                                },
                                _ => {},
                            }
                        },
                        Err(error) if self.verbose => {
                            eprintln!("Error on loading single account: {error}");
                        },
                        _ => {},
                    }
                }
            },
            Err(error) if self.verbose => {
                eprintln!("Error on loading accounts: {error}");
            },
            _ => {},
        }

        if self.verbose {
            println!("Loaded {} accounts successfully", out_vec.len());
        }

        out_vec
    }
    
    /// Returns full path to map.toml
    /// This path will be relative to $PWD, not to config.
    ///
    /// # Examples
    /// ```rust
    /// use squad_quest::{config::Config,error::Error,map::Map,SquadObject};
    /// # fn main() {
    /// # let _ = wrapper();
    /// # }
    /// # fn wrapper() -> Result<(),Error> {
    ///
    /// let path = "cfg/config.toml".into();
    /// let config = Config::load(path);
    /// 
    /// let map_path = config.full_map_path();
    /// let map = Map::load(map_path)?;
    /// # Ok(())
    /// # }
    /// ```
    pub fn full_map_path(&self) -> PathBuf {
        let mut path = self.path.clone();
        path.push(self.map.clone());
        path
    }
}