use std::sync::mpsc::channel;
use std::time::Duration;
use std::{env, fs, path};

use fs_extra::dir;
use notify::{DebouncedEvent, RecommendedWatcher, RecursiveMode, Watcher};
use toml::Value;

use config::Config;
use post::{parse_post, read_posts_dir};
use write::{write_post, write_post_listing};

pub fn build(include_drafts: bool) {
    let cwd = env::current_dir().expect("Couldn't read current directory");
    let config = match fs::read_to_string(cwd.join("casaubon.toml")) {
        Ok(contents) => match contents.parse::<Value>() {
            Ok(config) => Config {
                site_name: String::from(config["site_name"].as_str().unwrap()),
            },
            Err(_) => panic!("Invalid casaubon.toml"),
        },
        Err(_) => {
            panic!("Can't find casaubon.toml");
        }
    };

    match fs::read_dir(cwd.join("public")) {
        Ok(_) => {
            fs::remove_dir_all(cwd.join("public")).unwrap();
        }
        Err(_) => {}
    }

    fs::create_dir(cwd.join("public")).expect("Couldn't create public directory");

    let layout_template = fs::read_to_string(&cwd.join("templates").join("layout.html"))
        .expect("Couldn't find layout template");
    let post_template = fs::read_to_string(cwd.join("templates").join("post.html"))
        .expect("Couldn't find post template");
    let post_listing_template = fs::read_to_string(cwd.join("templates").join("post_listing.html"))
        .expect("Couldn't find post listing item template");
    let post_item_template =
        fs::read_to_string(cwd.join("templates").join("post_listing_item.html"))
            .expect("Couldn't find post listing item template");

    let post_paths = match include_drafts {
        true => {
            let mut posts = read_posts_dir(&cwd.join("posts"));
            posts.append(&mut read_posts_dir(&cwd.join("drafts")));
            posts
        }
        false => read_posts_dir(&cwd.join("posts")),
    };

    let posts = post_paths
        .into_iter()
        .map(|entry| {
            let post = parse_post(entry.path());
            write_post(&cwd, &layout_template, &post_template, &post, &config);
            post
        })
        .collect();

    write_post_listing(
        &cwd,
        &layout_template,
        &post_listing_template,
        &post_item_template,
        &posts,
        &config,
    );

    fs_extra::copy_items(
        &vec![cwd.join("css"), cwd.join("js")],
        cwd.join("public"),
        &dir::CopyOptions::new(),
    )
    .expect("Couldn't copy css/js directories");
}

pub fn new(name: &str) {
    let cwd = env::current_dir().expect("Couldn't read current directory");
    let project_path = cwd.join(name);

    fs::create_dir(&project_path).expect(&format!("Couldn't create directory '{}'", &name));
    fs::write(
        project_path.join("casaubon.toml"),
        format!("site_name = \"{}\"", &name),
    )
    .expect("Could not create casaubon.toml");

    for dir in &["drafts", "posts", "public", "templates", "css", "js"] {
        fs::create_dir(&project_path.join(&dir))
            .expect(&format!("Couldn't create {} directory", &dir));
    }

    fs::write(project_path.join("css").join("style.css"), "")
        .expect("Couldn't create css/style.css");
    fs::write(project_path.join("js").join("index.js"), "").expect("Couldn't create js/index.js");

    for file in &["layout", "post_listing", "post", "post_listing_item"] {
        fs::write(
            &project_path
                .join("templates")
                .join(format!("{}.html", file)),
            "",
        )
        .expect(&format!("Couldn't write templates/{}.html", file));
    }
}

fn should_rebuild(cwd: &path::PathBuf, path: &path::PathBuf) -> bool {
    let path_string = path.to_str().unwrap().to_string();
    let change_is_from_public = path_string.contains(cwd.join("public").to_str().unwrap());
    let change_is_from_git = path_string.contains(cwd.join(".git").to_str().unwrap());

    !change_is_from_public && !change_is_from_git
}

pub fn watch(include_drafts: bool) -> notify::Result<()> {
    let cwd = env::current_dir().expect("Couldn't read current directory");
    let (tx, rx) = channel();
    let mut watcher: RecommendedWatcher = try!(Watcher::new(tx, Duration::from_secs(2)));
    try!(watcher.watch(&cwd, RecursiveMode::Recursive));
    println!("Watching {}", cwd.to_str().unwrap());

    let handle_event = |path: &path::PathBuf| {
        if should_rebuild(&cwd, &path) {
            println!("Rebuilding");
            build(include_drafts);
        }
    };

    loop {
        match rx.recv() {
            Ok(e) => match e {
                DebouncedEvent::Create(path) => {
                    handle_event(&path);
                }
                DebouncedEvent::Write(path) => {
                    handle_event(&path);
                }
                _ => {}
            },
            Err(e) => println!("watch error: {:?}", e),
        }
    }
}

#[cfg(test)]
mod tests {
    #[allow(unused_imports)]
    use super::*;
    #[allow(unused_imports)]
    use uuid::Uuid;

    #[test]
    fn test_new() {
        let temp_dir = env::temp_dir();
        env::set_current_dir(&temp_dir).unwrap();

        let uuid = Uuid::new_v4().to_string();
        let project_dir = temp_dir.join(&uuid);
        new(&uuid);

        for dir in &["public", "posts", "templates"] {
            fs::read_dir(&project_dir.join(dir)).unwrap();
        }

        assert_eq!(
            "",
            fs::read_to_string(&project_dir.join("templates").join("post_listing.html")).unwrap()
        );
        assert_eq!(
            "",
            fs::read_to_string(&project_dir.join("templates").join("layout.html")).unwrap()
        );
        assert_eq!(
            "",
            fs::read_to_string(&project_dir.join("templates").join("post_listing_item.html"))
                .unwrap()
        );
        assert_eq!(
            "",
            fs::read_to_string(&project_dir.join("templates").join("post.html")).unwrap()
        );
        assert_eq!(
            "",
            fs::read_to_string(&project_dir.join("css").join("style.css")).unwrap()
        );
        assert_eq!(
            "",
            fs::read_to_string(&project_dir.join("js").join("index.js")).unwrap()
        );
        assert_eq!(
            format!("site_name = \"{}\"", &uuid),
            fs::read_to_string(&project_dir.join("casaubon.toml")).unwrap()
        );

        fs::remove_dir_all(project_dir).unwrap();
    }

    #[test]
    fn test_build() {
        let temp_dir = env::temp_dir();
        let uuid = Uuid::new_v4().to_string();
        let project_dir = temp_dir.join(&uuid);
        fs::create_dir(&project_dir).unwrap();
        env::set_current_dir(&project_dir).unwrap();

        fs::create_dir(project_dir.join("posts")).unwrap();
        fs::create_dir(project_dir.join("public")).unwrap();
        fs::create_dir(project_dir.join("templates")).unwrap();
        fs::create_dir(project_dir.join("css")).unwrap();
        fs::create_dir(project_dir.join("js")).unwrap();

        fs::write(
            project_dir.join("css").join("style.css"),
            "body { background: blue; }",
        )
        .unwrap();
        fs::write(
            project_dir.join("js").join("index.js"),
            "window.onload = function () { alert() }",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("layout.html"),
            "<html><head><title>{{ page_title }}</title></head><body>{{ contents }}</body></html>",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("post.html"),
            "<article><h1>{{ title }}</h1><div>{{ body }}</div></article>",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("post_listing.html"),
            "<ul>{{ post_listing }}</ul>",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("post_listing_item.html"),
            "<li><a href=\"/{{ slug }}\">{{ title }}</a></li>",
        )
        .unwrap();
        fs::write(
            project_dir.join("posts").join("first-post.md"),
            "# First post\n\nThis is the first post\n\nIt has multiple paragraphs",
        )
        .unwrap();
        fs::write(project_dir.join("casaubon.toml"), "site_name = \"Test Site\"").unwrap();

        build(false);

        assert_eq!(
            "<html><head><title>Test Site</title></head><body><ul><li><a href=\"/fir\
             st-post\">First post</a></li></ul></body></html>",
            fs::read_to_string(project_dir.join("public").join("index.html")).unwrap(),
        );

        assert_eq!(
            "<html><head><title>First post | Test Site</title></head><body><article><h1>First pos\
             t</h1><div><p>This is the first post</p><p>It has multiple paragra\
             phs</p></div></article></body></html>",
            fs::read_to_string(
                project_dir
                    .join("public")
                    .join("first-post")
                    .join("index.html")
            )
            .unwrap()
            .replace("\n", ""),
        );

        assert_eq!(
            "body { background: blue; }",
            fs::read_to_string(project_dir.join("public").join("css").join("style.css")).unwrap()
        );

        assert_eq!(
            "window.onload = function () { alert() }",
            fs::read_to_string(project_dir.join("public").join("js").join("index.js")).unwrap()
        );

        fs::remove_dir_all(project_dir).unwrap();
    }

    #[test]
    fn test_build_drafts() {
        let temp_dir = env::temp_dir();
        let uuid = Uuid::new_v4().to_string();
        let project_dir = temp_dir.join(&uuid);
        fs::create_dir(&project_dir).unwrap();
        env::set_current_dir(&project_dir).unwrap();

        fs::create_dir(project_dir.join("drafts")).unwrap();
        fs::create_dir(project_dir.join("posts")).unwrap();
        fs::create_dir(project_dir.join("public")).unwrap();
        fs::create_dir(project_dir.join("templates")).unwrap();
        fs::create_dir(project_dir.join("css")).unwrap();
        fs::create_dir(project_dir.join("js")).unwrap();

        fs::write(
            project_dir.join("css").join("style.css"),
            "body { background: blue; }",
        )
        .unwrap();
        fs::write(
            project_dir.join("js").join("index.js"),
            "window.onload = function () { alert() }",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("layout.html"),
            "<html><head><title>{{ page_title }}</title></head><body>{{ contents }}</body></html>",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("post.html"),
            "<article><h1>{{ title }}</h1><div>{{ body }}</div></article>",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("post_listing.html"),
            "<ul>{{ post_listing }}</ul>",
        )
        .unwrap();
        fs::write(
            project_dir.join("templates").join("post_listing_item.html"),
            "<li><a href=\"/{{ slug }}\">{{ title }}</a></li>",
        )
        .unwrap();
        fs::write(
            project_dir.join("posts").join("first-post.md"),
            "# First post\n\nThis is the first post",
        )
        .unwrap();
        fs::write(
            project_dir.join("drafts").join("first-draft.md"),
            "# First draft\n\nThis is the first draft",
        )
        .unwrap();
        fs::write(project_dir.join("casaubon.toml"), "site_name = \"Test Site\"").unwrap();

        build(true);

        assert_eq!(
            "<html><head><title>Test Site</title></head><body><ul><li><a href=\"/first-post\">First post</a></li><li><a href=\"/first-draft\">First draft</a></li></ul></body></html>",
            fs::read_to_string(project_dir.join("public").join("index.html")).unwrap().replace("\n", ""),
        );

        assert_eq!(
            "<html><head><title>First post | Test Site</title></head><body><article><h1>First post</h1><div><p>This is the first post</p></div></article></body></html>",
            fs::read_to_string(
                project_dir
                    .join("public")
                    .join("first-post")
                    .join("index.html")
            ).unwrap()
            .replace("\n", ""),
        );

        assert_eq!(
            "<html><head><title>First draft | Test Site</title></head><body><article><h1>First draft</h1><div><p>This is the first draft</p></div></article></body></html>",
            fs::read_to_string(
                project_dir
                    .join("public")
                    .join("first-draft")
                    .join("index.html")
            ).unwrap()
            .replace("\n", ""),
        );

        fs::remove_dir_all(project_dir).unwrap();
    }

    #[test]
    fn test_should_rebuild() {
        let cwd = env::current_dir().unwrap();
        assert_eq!(
            false,
            should_rebuild(&cwd, &cwd.join("public").join("index.html"))
        );
        assert_eq!(
            false,
            should_rebuild(&cwd, &cwd.join(".git").join("index.html"))
        );
        assert_eq!(
            true,
            should_rebuild(&cwd, &cwd.join("posts").join("test.md"))
        );
        assert_eq!(
            true,
            should_rebuild(&cwd, &cwd.join("drafts").join("test.md"))
        );
        assert_eq!(
            true,
            should_rebuild(&cwd, &cwd.join("css").join("style.css"))
        );
        assert_eq!(true, should_rebuild(&cwd, &cwd.join("js").join("index.js")));
    }
}