pub mod bookitem;
pub mod bookconfig;

pub mod bookconfig_test;

pub use self::bookitem::{BookItem, BookItems};
pub use self::bookconfig::BookConfig;

use std::path::{Path, PathBuf};
use std::fs::{self, File};
use std::error::Error;
use std::io;
use std::io::Write;
use std::io::ErrorKind;
use std::process::Command;

use {theme, parse, utils};
use renderer::{Renderer, HtmlHandlebars};


pub struct MDBook {
    root: PathBuf,
    dest: PathBuf,
    src: PathBuf,
    theme_path: PathBuf,

    pub title: String,
    pub author: String,
    pub description: String,

    pub content: Vec<BookItem>,
    renderer: Box<Renderer>,

    livereload: Option<String>,

    /// Should `mdbook build` create files referenced from SUMMARY.md if they
    /// don't exist
    pub create_missing: bool,

    pub google_analytics: Option<String>,
}

impl MDBook {
    /// Create a new `MDBook` struct with root directory `root`
    ///
    /// # Examples
    ///
    /// ```no_run
    /// # extern crate mdbook;
    /// # use mdbook::MDBook;
    /// # use std::path::Path;
    /// # fn main() {
    /// let book = MDBook::new(Path::new("root_dir"));
    /// # }
    /// ```
    ///
    /// In this example, `root_dir` will be the root directory of our book
    /// and is specified in function of the current working directory
    /// by using a relative path instead of an
    /// absolute path.
    ///
    /// Default directory paths:
    ///
    /// - source: `root/src`
    /// - output: `root/book`
    /// - theme: `root/theme`
    ///
    /// They can both be changed by using [`set_src()`](#method.set_src) and
    /// [`set_dest()`](#method.set_dest)

    pub fn new(root: &Path) -> MDBook {

        if !root.exists() || !root.is_dir() {
            warn!("{:?} No directory with that name", root);
        }

        MDBook {
            root: root.to_owned(),
            dest: root.join("book"),
            src: root.join("src"),
            theme_path: root.join("theme"),

            title: String::new(),
            author: String::new(),
            description: String::new(),

            content: vec![],
            renderer: Box::new(HtmlHandlebars::new()),

            livereload: None,
            create_missing: true,
            google_analytics: None,
        }
    }

    /// Returns a flat depth-first iterator over the elements of the book,
    /// it returns an [BookItem enum](bookitem.html):
    /// `(section: String, bookitem: &BookItem)`
    ///
    /// ```no_run
    /// # extern crate mdbook;
    /// # use mdbook::MDBook;
    /// # use mdbook::BookItem;
    /// # use std::path::Path;
    /// # fn main() {
    /// # let mut book = MDBook::new(Path::new("mybook"));
    /// for item in book.iter() {
    ///     match item {
    ///         &BookItem::Chapter(ref section, ref chapter) => {},
    ///         &BookItem::Affix(ref chapter) => {},
    ///         &BookItem::Spacer => {},
    ///     }
    /// }
    ///
    /// // would print something like this:
    /// // 1. Chapter 1
    /// // 1.1 Sub Chapter
    /// // 1.2 Sub Chapter
    /// // 2. Chapter 2
    /// //
    /// // etc.
    /// # }
    /// ```

    pub fn iter(&self) -> BookItems {
        BookItems {
            items: &self.content[..],
            current_index: 0,
            stack: Vec::new(),
        }
    }

    /// `init()` creates some boilerplate files and directories
    /// to get you started with your book.
    ///
    /// ```text
    /// book-test/
    /// ├── book
    /// └── src
    ///     ├── chapter_1.md
    ///     └── SUMMARY.md
    /// ```
    ///
    /// It uses the paths given as source and output directories
    /// and adds a `SUMMARY.md` and a
    /// `chapter_1.md` to the source directory.

    pub fn init(&mut self) -> Result<(), Box<Error>> {

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

        if !self.root.exists() {
            fs::create_dir_all(&self.root).unwrap();
            info!("{:?} created", &self.root);
        }

        {

            if !self.dest.exists() {
                debug!("[*]: {:?} does not exist, trying to create directory", self.dest);
                fs::create_dir_all(&self.dest)?;
            }

            if !self.src.exists() {
                debug!("[*]: {:?} does not exist, trying to create directory", self.src);
                fs::create_dir_all(&self.src)?;
            }

            let summary = self.src.join("SUMMARY.md");

            if !summary.exists() {

                // Summary does not exist, create it

                debug!("[*]: {:?} does not exist, trying to create SUMMARY.md", self.src.join("SUMMARY.md"));
                let mut f = File::create(&self.src.join("SUMMARY.md"))?;

                debug!("[*]: Writing to SUMMARY.md");

                writeln!(f, "# Summary")?;
                writeln!(f, "")?;
                writeln!(f, "- [Chapter 1](./chapter_1.md)")?;
            }
        }

        // parse SUMMARY.md, and create the missing item related file
        self.parse_summary()?;

        debug!("[*]: constructing paths for missing files");
        for item in self.iter() {
            debug!("[*]: item: {:?}", item);
            let ch = match *item {
                BookItem::Spacer => continue,
                BookItem::Chapter(_, ref ch) |
                BookItem::Affix(ref ch) => ch,
            };
            if !ch.path.as_os_str().is_empty() {
                let path = self.src.join(&ch.path);

                if !path.exists() {
                    if !self.create_missing {
                        return Err(format!("'{}' referenced from SUMMARY.md does not exist.", path.to_string_lossy())
                                       .into());
                    }
                    debug!("[*]: {:?} does not exist, trying to create file", path);
                    ::std::fs::create_dir_all(path.parent().unwrap())?;
                    let mut f = File::create(path)?;

                    // debug!("[*]: Writing to {:?}", path);
                    writeln!(f, "# {}", ch.name)?;
                }
            }
        }

        debug!("[*]: init done");
        Ok(())
    }

    pub fn create_gitignore(&self) {
        let gitignore = self.get_gitignore();

        if !gitignore.exists() {
            // Gitignore does not exist, create it

            // Because of `src/book/mdbook.rs#L37-L39`,
            // `dest` will always start with `root`.
            // If it is not, `strip_prefix` will return an Error.
            if !self.get_dest().starts_with(&self.root) {
                return;
            }

            let relative = self.get_dest()
                .strip_prefix(&self.root)
                .expect("Destination is not relative to root.");
            let relative = relative
                .to_str()
                .expect("Path could not be yielded into a string slice.");

            debug!("[*]: {:?} does not exist, trying to create .gitignore", gitignore);

            let mut f = File::create(&gitignore).expect("Could not create file.");

            debug!("[*]: Writing to .gitignore");

            writeln!(f, "{}", relative).expect("Could not write to file.");
        }
    }

    /// The `build()` method is the one where everything happens.
    /// First it parses `SUMMARY.md` to construct the book's structure
    /// in the form of a `Vec<BookItem>` and then calls `render()`
    /// method of the current renderer.
    ///
    /// It is the renderer who generates all the output files.
    pub fn build(&mut self) -> Result<(), Box<Error>> {
        debug!("[fn]: build");

        self.init()?;

        // Clean output directory
        utils::fs::remove_dir_content(&self.dest)?;

        self.renderer.render(&self)?;

        Ok(())
    }


    pub fn get_gitignore(&self) -> PathBuf {
        self.root.join(".gitignore")
    }

    pub fn copy_theme(&self) -> Result<(), Box<Error>> {
        debug!("[fn]: copy_theme");

        let theme_dir = self.src.join("theme");

        if !theme_dir.exists() {
            debug!("[*]: {:?} does not exist, trying to create directory", theme_dir);
            fs::create_dir(&theme_dir)?;
        }

        // index.hbs
        let mut index = File::create(&theme_dir.join("index.hbs"))?;
        index.write_all(theme::INDEX)?;

        // book.css
        let mut css = File::create(&theme_dir.join("book.css"))?;
        css.write_all(theme::CSS)?;

        // favicon.png
        let mut favicon = File::create(&theme_dir.join("favicon.png"))?;
        favicon.write_all(theme::FAVICON)?;

        // book.js
        let mut js = File::create(&theme_dir.join("book.js"))?;
        js.write_all(theme::JS)?;

        // highlight.css
        let mut highlight_css = File::create(&theme_dir.join("highlight.css"))?;
        highlight_css.write_all(theme::HIGHLIGHT_CSS)?;

        // highlight.js
        let mut highlight_js = File::create(&theme_dir.join("highlight.js"))?;
        highlight_js.write_all(theme::HIGHLIGHT_JS)?;

        Ok(())
    }

    pub fn write_file<P: AsRef<Path>>(&self, filename: P, content: &[u8]) -> Result<(), Box<Error>> {
        let path = self.get_dest().join(filename);
        utils::fs::create_file(&path)
            .and_then(|mut file| file.write_all(content))
            .map_err(|e| io::Error::new(io::ErrorKind::Other, format!("Could not create {}: {}", path.display(), e)))?;
        Ok(())
    }

    /// Parses the `book.json` file (if it exists) to extract
    /// the configuration parameters.
    /// The `book.json` file should be in the root directory of the book.
    /// The root directory is the one specified when creating a new `MDBook`

    pub fn read_config(mut self) -> Self {

        let config = BookConfig::new(&self.root)
            .read_config(&self.root)
            .to_owned();

        self.title = config.title;
        self.description = config.description;
        self.author = config.author;

        self.dest = config.dest;
        self.src = config.src;
        self.theme_path = config.theme_path;

        self
    }

    /// You can change the default renderer to another one
    /// by using this method. The only requirement
    /// is for your renderer to implement the
    /// [Renderer trait](../../renderer/renderer/trait.Renderer.html)
    ///
    /// ```no_run
    /// extern crate mdbook;
    /// use mdbook::MDBook;
    /// use mdbook::renderer::HtmlHandlebars;
    /// # use std::path::Path;
    ///
    /// fn main() {
    ///     let mut book = MDBook::new(Path::new("mybook"))
    ///                         .set_renderer(Box::new(HtmlHandlebars::new()));
    ///
    /// // In this example we replace the default renderer
    /// // by the default renderer...
    /// // Don't forget to put your renderer in a Box
    /// }
    /// ```
    ///
    /// **note:** Don't forget to put your renderer in a `Box`
    /// before passing it to `set_renderer()`

    pub fn set_renderer(mut self, renderer: Box<Renderer>) -> Self {
        self.renderer = renderer;
        self
    }

    pub fn test(&mut self) -> Result<(), Box<Error>> {
        // read in the chapters
        self.parse_summary()?;
        for item in self.iter() {

            if let BookItem::Chapter(_, ref ch) = *item {
                if ch.path != PathBuf::new() {

                    let path = self.get_src().join(&ch.path);

                    println!("[*]: Testing file: {:?}", path);

                    let output_result = Command::new("rustdoc").arg(&path).arg("--test").output();
                    let output = output_result?;

                    if !output.status.success() {
                        return Err(Box::new(io::Error::new(ErrorKind::Other,
                                                           format!("{}\n{}",
                                                                   String::from_utf8_lossy(&output.stdout),
                                                                   String::from_utf8_lossy(&output.stderr)))) as
                                   Box<Error>);
                    }
                }
            }
        }
        Ok(())
    }

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

    pub fn set_dest(mut self, dest: &Path) -> Self {

        // Handle absolute and relative paths
        if dest.is_absolute() {
            self.dest = dest.to_owned();
        } else {
            let dest = self.root.join(dest).to_owned();
            self.dest = dest;
        }

        self
    }

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

    pub fn set_src(mut self, src: &Path) -> Self {

        // Handle absolute and relative paths
        if src.is_absolute() {
            self.src = src.to_owned();
        } else {
            let src = self.root.join(src).to_owned();
            self.src = src;
        }

        self
    }

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

    pub fn set_title(mut self, title: &str) -> Self {
        self.title = title.to_owned();
        self
    }

    pub fn get_title(&self) -> &str {
        &self.title
    }

    pub fn set_author(mut self, author: &str) -> Self {
        self.author = author.to_owned();
        self
    }

    pub fn get_author(&self) -> &str {
        &self.author
    }

    pub fn set_description(mut self, description: &str) -> Self {
        self.description = description.to_owned();
        self
    }

    pub fn get_description(&self) -> &str {
        &self.description
    }

    pub fn set_livereload(&mut self, livereload: String) -> &mut Self {
        self.livereload = Some(livereload);
        self
    }

    pub fn unset_livereload(&mut self) -> &Self {
        self.livereload = None;
        self
    }

    pub fn get_livereload(&self) -> Option<&String> {
        self.livereload.as_ref()
    }

    pub fn set_theme_path(mut self, theme_path: &Path) -> Self {
        self.theme_path = if theme_path.is_absolute() {
            theme_path.to_owned()
        } else {
            self.root.join(theme_path).to_owned()
        };
        self
    }

    pub fn get_theme_path(&self) -> &Path {
        &self.theme_path
    }

    // Construct book
    fn parse_summary(&mut self) -> Result<(), Box<Error>> {
        // When append becomes stable, use self.content.append() ...
        self.content = parse::construct_bookitems(&self.src.join("SUMMARY.md"))?;
        Ok(())
    }
}