/* 
 * Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
 * SPDX-License-Identifier: AGPL-3.0-or-later
 *
 * This file is part of Plaque.
 *
 * Plaque is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Affero General Public License as published by the Free 
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version.
 * 
 * Plaque is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see https://www.gnu.org/licenses/.
 */

use std::{
  env,
  fs::File,
  io::Read,
};

use charsets::Charset;
use isolang::Language;
use serde::Deserialize;
use serde_with::{ serde_as, DisplayFromStr };
use toml::{ de::ValueDeserializer, Value };
use yacexits::*;

#[derive(Deserialize)]
pub struct Config {
  pub content_dir: String,
  pub output_dir: String,
  pub template_dir: String,
}

#[serde_as]
#[derive(Deserialize)]
pub struct PageMeta {
  pub author: String,
  
  pub date: String,

  #[serde_as(as = "DisplayFromStr")]
  pub encoding: Charset,

  pub lang: Language,

  pub template: String,

  pub kind: String,
}

pub fn get_path(xdg: &str) -> Result<String, (String, u32)> {
  let dir: String;
  
  if unsafe { libc::geteuid() } == 0 {
    dir = match xdg {
      "XDG_CACHE_HOME" => "/var/cms".to_owned(),
      "XDG_CONFIG_HOME" => "/etc/cms".to_owned(),
      _ => panic!("nya"),
    };
  } else {
    dir = match env::var(xdg) {
      Ok(val) => val,
      Err(_) => {
        match env::var("HOME") {
          Ok(home) => format!("{}/.config/", home),
          Err(_) => {
            return Err((
              "Unable to determine path to current user’s home directory."
                .to_string(),
              EX_UNAVAILABLE
            ));
          },
        }
      },
    };
  }
  match xdg {
    "XDG_CACHE_HOME" => Ok(format!("{}/cms", dir)),
    "XDG_CONFIG_HOME" => Ok(format!("{}/cms", dir)),
    _ => panic!("nya"),
  }
}

impl Config {
  pub fn read_config(config_path: String) -> Result<Self, (String, u32)> {
    let mut buf: Vec<u8> = Vec::new();

    let mut config_file = match File::open(
      format!("{}/config.toml", config_path)
    ) {
      Ok(file) => file,
      Err(err) => return Err((format!("{:?}", err), 1)),
    };

    match config_file.read_to_end(&mut buf) {
      Ok(_) => {},
      Err(err) => return Err((format!("{:?}", err), 1)),
    };

    let toml = String::from_utf8(buf).unwrap();

    match Config::deserialize(ValueDeserializer::new(&toml)) {
      Ok(val) => Ok(val),
      Err(err) => Err((format!("{:?}", err), 1)),
    }
  }
}

impl PageMeta {
  pub fn read_meta(toml: Value) -> Result<Self, (String, u32)> {
    let input: String = match toml.try_into() {
      Ok(val) => val,
      Err(_) => {
        return Err((format!("Failed to read page metadata."), EX_DATAERR));
      },
    };

    match Self::deserialize(ValueDeserializer::new(&input)) {
      Ok(val) => Ok(val),
      Err(_) => {
        Err(("Could not deserialized TOML.".to_owned(), EX_DATAERR))
      },
    }
  }
}