extern crate rustc_serialize;
use self::rustc_serialize::json::Json;
use std::fs::File;
use std::io::Read;
use std::path::{Path, PathBuf};

#[derive(Debug, Clone)]
pub struct BookConfig {
    pub title: String,
    pub author: String,
    root: PathBuf,
    dest: PathBuf,
    src: PathBuf,
    pub indent_spaces: i32,
    multilingual: bool,
}


impl BookConfig {
    pub fn new(root: &Path) -> Self {
        BookConfig {
            title: String::new(),
            author: String::new(),
            root: root.to_owned(),
            dest: PathBuf::from("book"),
            src: PathBuf::from("src"),
            indent_spaces: 4,               // indentation used for SUMMARY.md
            multilingual: false,
        }
    }

    pub fn read_config(&mut self, root: &Path) -> &mut Self {

        debug!("[fn]: read_config");

        // If the file does not exist, return early
        let mut config_file = match File::open(root.join("book.json")) {
            Ok(f) => f,
            Err(_) => {
                debug!("[*]: Failed to open {:?}", root.join("book.json"));
                return self
            },
        };

        debug!("[*]: Reading config");
        let mut data = String::new();

        // Just return if an error occured.
        // I would like to propagate the error, but I have to return `&self`
        match config_file.read_to_string(&mut data) {
            Err(_) => return self,
            _ => {},
        }

        // Convert to JSON
        if let Ok(config) = Json::from_str(&data) {
            // Extract data

            debug!("[*]: Extracting data from config");
            // Title & author
            if let Some(a) = config.find_path(&["title"]) { self.title = a.to_string().replace("\"", "") }
            if let Some(a) = config.find_path(&["author"]) { self.author = a.to_string().replace("\"", "") }

            // Destination
            if let Some(a) = config.find_path(&["dest"]) {
                let dest = PathBuf::from(&a.to_string().replace("\"", ""));

                // If path is relative make it absolute from the parent directory of src
                match dest.is_relative() {
                    true => {
                        let dest = self.get_root().join(&dest).to_owned();
                        self.set_dest(&dest);
                    },
                    false => { self.set_dest(&dest); },
                }
            }
        }

        self
    }

    pub fn get_root(&self) -> &Path {
        &self.root
    }

    pub fn set_root(&mut self, root: &Path) -> &mut Self {
        self.root = root.to_owned();
        self
    }

    pub fn get_dest(&self) -> &Path {
        &self.dest
    }

    pub fn set_dest(&mut self, dest: &Path) -> &mut Self {
        self.dest = dest.to_owned();
        self
    }

    pub fn get_src(&self) -> &Path {
        &self.src
    }

    pub fn set_src(&mut self, src: &Path) -> &mut Self {
        self.src = src.to_owned();
        self
    }

}