// Copyright (C) 2016 Élisabeth HENRY.
//
// This file is part of Crowbook.
//
// Crowbook is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// Caribon 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 Lesser General Public License for more details.
//
// You should have received ba copy of the GNU Lesser General Public License
// along with Crowbook.  If not, see <http://www.gnu.org/licenses/>.

use error::{Error, Result, Source};
use html::HtmlRenderer;
use book::{Book, compile_str};
use token::Token;
use templates::img;
use resource_handler;
use renderer::Renderer;
use parser::Parser;

use std::io::{Read, Write};
use std::fs;
use std::fs::File;
use std::path::Path;
use std::path::PathBuf;
use std::borrow::Cow;
use std::convert::{AsRef, AsMut};


/// Multiple files HTML renderer
///
/// Renders HTML in a given directory.
pub struct HtmlDirRenderer<'a> {
    html: HtmlRenderer<'a>,
}

impl<'a> HtmlDirRenderer<'a> {
    /// Creates a new HtmlDirRenderer
    pub fn new(book: &'a Book) -> HtmlDirRenderer<'a> {
        let mut html = HtmlRenderer::new(book);
        html.handler.set_images_mapping(true);
        html.handler.set_base64(false);
        HtmlDirRenderer { html: html }
    }

    /// Set aproofreading to true
    pub fn proofread(mut self) -> HtmlDirRenderer<'a> {
        self.html.proofread = true;
        self
    }

    /// Render a book
    pub fn render_book(&mut self) -> Result<()> {
        // Add internal files to resource handler
        for (i, filename) in self.html.book.filenames.iter().enumerate() {
            self.html.handler.add_link(filename.clone(), filenamer(i));
        }

        // Create the directory
        let dest_path = if self.html.proofread {
            try!(self.html.book.options.get_path("output.proofread.html_dir"))
        } else {
            try!(self.html.book.options.get_path("output.html_dir"))
        };
        match fs::metadata(&dest_path) {
            Ok(metadata) => {
                if metadata.is_file() {
                    return Err(Error::render(&self.html.book.source,
                                             lformat!("{path} already exists and is not a \
                                                       directory",
                                                      path = &dest_path)));
                } else if metadata.is_dir() {
                    self.html
                        .book
                        .logger
                        .warning(lformat!("{path} already exists, deleting it", path = &dest_path));
                    try!(fs::remove_dir_all(&dest_path).map_err(|e| {
                        Error::render(&self.html.book.source,
                                      lformat!("error deleting directory {path}: {error}",
                                               path = &dest_path,
                                               error = e))
                    }));
                }
            }
            Err(_) => (),
        }
        try!(fs::DirBuilder::new()
            .recursive(true)
            .create(&dest_path)
            .map_err(|e| {
                Error::render(&self.html.book.source,
                              lformat!("could not create HTML directory {path}: {error}",
                                       path = &dest_path,
                                       error = e))
            }));

        // Write CSS
        try!(self.write_css());
        // Write print.css
        try!(self.write_file("print.css",
                             &self.html.book.get_template("html.css.print").unwrap().as_bytes()));
        // Write index.html and chapter_xxx.html
        try!(self.write_html());
        // Write menu.svg
        try!(self.write_file("menu.svg", img::MENU_SVG));

        // Write highlight files if they are needed
        if self.html.book.options.get_bool("html.highlight_code") == Ok(true) {
            try!(self.write_file("highlight.js",
                                 self.html
                                     .book
                                     .get_template("html.highlight.js")
                                     .unwrap()
                                     .as_bytes()));
            try!(self.write_file("highlight.css",
                                 self.html
                                     .book
                                     .get_template("html.highlight.css")
                                     .unwrap()
                                     .as_bytes()));
        }

        // Write all images (including cover)
        for (source, dest) in self.html.handler.images_mapping() {
            let mut f = try!(File::open(source).map_err(|_| {
                Error::file_not_found(&self.html.book.source,
                                      lformat!("image or cover"),
                                      source.clone())
            }));
            let mut content = vec![];
            try!(f.read_to_end(&mut content).map_err(|e| {
                Error::render(&self.html.book.source,
                              lformat!("error while reading image file {file}: {error}",
                                       file = source,
                                       error = e))
            }));
            try!(self.write_file(dest, &content));
        }

        // Write additional files
        if let Ok(list) = self.html.book.options.get_paths_list("resources.files") {
            let files_path = self.html.book.options.get_path("resources.base_path.files").unwrap();
            let data_path =
                Path::new(self.html.book.options.get_relative_path("resources.out_path").unwrap());
            let list = try!(resource_handler::get_files(list, &files_path));
            for path in list {
                let abs_path = Path::new(&files_path).join(&path);
                let mut f = try!(File::open(&abs_path).map_err(|_| {
                    Error::file_not_found(&self.html.book.source,
                                          lformat!("additional resource from resources.files"),
                                          abs_path.to_string_lossy().into_owned())
                }));
                let mut content = vec![];
                try!(f.read_to_end(&mut content).map_err(|e| {
                    Error::render(&self.html.book.source,
                                  lformat!("error while reading resource file: {error}", error = e))
                }));
                try!(self.write_file(data_path.join(&path).to_str().unwrap(), &content));
            }
        }

        Ok(())
    }

    // Render each chapter and write them, and index.html too
    fn write_html(&mut self) -> Result<()> {
        let mut chapters = vec![];
        let mut titles = vec![];
        for (i, &(n, ref v)) in self.html.book.chapters.iter().enumerate() {
            self.html.chapter_config(i, n, filenamer(i));
            let mut title = String::new();
            for token in v {
                match *token {
                    Token::Header(1, ref vec) => {
                        if self.html.current_hide || self.html.current_numbering == 0 {
                            title = try!(self.html.render_vec(vec));
                        } else {
                            title = try!(self.html
                                .book
                                .get_chapter_header(self.html.current_chapter[0] + 1,
                                                    try!(self.html.render_vec(vec)),
                                                    |s| {
                                                        self.render_vec(&try!(Parser::new()
                                                            .parse_inline(s)))
                                                    }));
                        }
                        break;
                    }
                    _ => {
                        continue;
                    }
                }
            }
            titles.push(title);

            let chapter = HtmlRenderer::render_html(self, v, true);
            chapters.push(chapter);
        }
        self.html.source = Source::empty();
        let toc = self.html.toc.render();

        // render all chapters
        let template =
            try!(compile_str(try!(self.html.book.get_template("html_dir.chapter.html")).as_ref(),
                             &self.html.book.source,
                             lformat!("could not compile template 'html_dir.chapter.html")));
        for (i, content) in chapters.into_iter().enumerate() {
            let prev_chapter = if i > 0 {
                format!("<p class = \"prev_chapter\">
  <a href = \"{}\">
    « {}
  </a>
</p>",
                        filenamer(i - 1),
                        titles[i - 1])
            } else {
                String::new()
            };

            let next_chapter = if i < titles.len() - 1 {
                format!("<p class = \"next_chapter\">
  <a href = \"{}\">
    {} »
  </a>
</p>",
                        filenamer(i + 1),
                        titles[i + 1])
            } else {
                String::new()
            };


            // Render each HTML document
            let mut mapbuilder = try!(self.html
                    .book
                    .get_metadata(|s| self.render_vec(&try!(Parser::new().parse_inline(s)))))
                .insert_str("content", try!(content))
                .insert_str("chapter_title",
                            format!("{} – {}",
                                    self.html.book.options.get_str("title").unwrap(),
                                    titles[i]))
                .insert_str("toc", toc.clone())
                .insert_str("prev_chapter", prev_chapter)
                .insert_str("next_chapter", next_chapter)
                .insert_str("footer", try!(HtmlRenderer::get_footer(self)))
                .insert_str("header", try!(HtmlRenderer::get_header(self)))
                .insert_str("script", self.html.book.get_template("html.js").unwrap())
                .insert_bool(self.html.book.options.get_str("lang").unwrap(), true);

            if self.html.book.options.get_bool("html.highlight_code").unwrap() == true {
                mapbuilder = mapbuilder.insert_bool("highlight_code", true);
            }
            let data = mapbuilder.build();
            let mut res = vec![];
            template.render_data(&mut res, &data);
            try!(self.write_file(&filenamer(i), &res));
        }

        let mut content = if let Ok(cover) = self.html.book.options.get_path("cover") {
            // checks first that cover exists
            if fs::metadata(&cover).is_err() {
                return Err(Error::file_not_found(&self.html.book.source, lformat!("cover"), cover));

            }
            format!("<div id = \"cover\">
  <img class = \"cover\" alt = \"{}\" src = \"{}\" />
</div>",
                    self.html.book.options.get_str("title").unwrap(),
                    try!(self.html.handler.map_image(&self.html.book.source, Cow::Owned(cover)))
                        .as_ref())
        } else {
            String::new()
        };

        // Insert toc inline if option is set
        if self.html.book.options.get_bool("rendering.inline_toc").unwrap() {

            content.push_str(&format!("<h1>{}</h1>
<div id = \"toc\">
{}
</div>
",
                                      try!(self.html.get_toc_name()),
                                      &toc));
        }

        if titles.len() > 1 {
            content.push_str(&format!("<p class = \"next_chapter\">
  <a href = \"{}\">
    {} »
  </a>
</p>",
                                      filenamer(0),
                                      titles[0]));
        }
        // Render index.html and write it too
        let mut mapbuilder = try!(self.html
                .book
                .get_metadata(|s| self.render_vec(&try!(Parser::new().parse_inline(s)))))
            .insert_str("content", content)
            .insert_str("header", try!(HtmlRenderer::get_header(self)))
            .insert_str("footer", try!(HtmlRenderer::get_footer(self)))
            .insert_str("toc", toc.clone())
            .insert_str("script", self.html.book.get_template("html.js").unwrap())
            .insert_bool(self.html.book.options.get_str("lang").unwrap(), true);
        if self.html.book.options.get_bool("html.highlight_code").unwrap() == true {
            mapbuilder = mapbuilder.insert_bool("highlight_code", true);
        }
        let data = mapbuilder.build();
        let template =
            try!(compile_str(try!(self.html.book.get_template("html_dir.index.html")).as_ref(),
                             &self.html.book.source,
                             lformat!("could not compile template 'html_dir.index.html")));
        let mut res = vec![];
        template.render_data(&mut res, &data);
        try!(self.write_file("index.html", &res));

        Ok(())
    }

    // Render the CSS file and write it
    fn write_css(&self) -> Result<()> {
        // Render the CSS
        let template_css = try!(compile_str(try!(self.html.book.get_template("html.css"))
                                                .as_ref(),
                                            &self.html.book.source,
                                            lformat!("could not compile template 'html.css")));
        let mut data = try!(self.html.book.get_metadata(|s| Ok(s.to_owned())));
        data = data.insert_str("colours",
                               try!(self.html.book.get_template("html.css.colours")));
        if self.html.proofread && self.html.book.options.get_bool("proofread.nb_spaces").unwrap() {
            data = data.insert_bool("display_spaces", true);
        }
        let data = data.build();
        let mut res: Vec<u8> = vec![];
        template_css.render_data(&mut res, &data);
        let css = String::from_utf8_lossy(&res);

        // Write it
        self.write_file("stylesheet.css", css.as_bytes())
    }

    // Write content to a file
    fn write_file(&self, file: &str, content: &[u8]) -> Result<()> {
        let dir_name = if self.html.proofread {
            self.html.book.options.get_path("output.proofread.html_dir").unwrap()
        } else {
            self.html.book.options.get_path("output.html_dir").unwrap()
        };
        let dest_path = PathBuf::from(&dir_name);
        if dest_path.starts_with("..") {
            panic!("html dir is asked to create a file outside of its directory, no way!");
        }
        let dest_file = dest_path.join(file);
        let dest_dir = dest_file.parent().unwrap();
        if !fs::metadata(dest_dir).is_ok() {
            // dir does not exist, create it
            try!(fs::DirBuilder::new()
                .recursive(true)
                .create(&dest_dir)
                .map_err(|e| {
                    Error::render(&self.html.book.source,
                                  lformat!("could not create directory in {path}: {error}",
                                           path = dest_dir.display(),
                                           error = e))
                }));
        }
        let mut f = try!(File::create(&dest_file).map_err(|e| {
            Error::render(&self.html.book.source,
                          lformat!("could not create file {file}: {error}",
                                   file = dest_file.display(),
                                   error = e))
        }));
        f.write_all(content)
            .map_err(|e| {
                Error::render(&self.html.book.source,
                              lformat!("could not write to file {file}: {error}",
                                       file = dest_file.display(),
                                       error = e))
            })
    }
}

/// Generate a file name given an int
fn filenamer(i: usize) -> String {
    format!("chapter_{:03}.html", i)
}

derive_html!{HtmlDirRenderer<'a>, HtmlRenderer::static_render_token}