// #[global_allocator]
// static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;

#[macro_use]
extern crate smart_default;
#[macro_use]
extern crate failure;
#[macro_use]
extern crate serde_derive;
#[macro_use]
extern crate log;

use std::path::{PathBuf, Path};
use std::collections::HashMap;
use std::fs::{File, DirEntry, OpenOptions};
use std::io::{Read, Write};
use std::{env, fs, io};
use failure::Fallible;
use clap;

mod hash_dict;
mod logging;
mod bread;
use bread::Bread;
use crate::hash_dict::HashDict;
use chrono::Datelike;
use itertools::Itertools;

#[derive(Serialize, Deserialize, Debug, SmartDefault, Clone)]
#[serde(default)]
pub struct AppConfig {
    #[default = "info"]
    logging: String,
    #[default = "https://www.ondrovo.com/bread"]
    web_url : String,
}

pub struct GalleryInfo {
    web_path: PathBuf,
    data_path: PathBuf,
    tpl_path: PathBuf,
    thumbs_path: PathBuf,
    base_url: String,
    templates: HashMap<String, String>,
    image_hashes: hash_dict::HashDict,
    latest_year: i32,
    oldest_year: i32,
}

impl GalleryInfo {
    /// Read a named template from file, reusing from cache if possible
    fn template(&mut self, name: &str) -> Fallible<String> {
        if let Some(text) = self.templates.get(name) {
            return Ok(text.clone());
        }

        let mut tpl = String::new();
        File::open(self.tpl_path.join(name))?.read_to_string(&mut tpl)?;
        self.templates.insert(name.to_string(), tpl.clone());
        Ok(tpl)
    }
}

const CONFIG_FILE: &str = "breadgen.json";

fn main() -> Fallible<()> {
    let version = clap::crate_version!();
    let clap =
        clap::App::new("Flowbox RT")
            .version(version)
            .arg(
                clap::Arg::with_name("config")
                    .short("c")
                    .long("config")
                    .value_name("FILE")
                    .help("Sets a custom config file (default: breadgen.json)")
                    .takes_value(true),
            );

    let clap = logging::add_clap_args(clap);
    let argv = clap.get_matches();

    /* Load config */
    let appcfg = {
        let confile = argv.value_of("config")
            .unwrap_or(CONFIG_FILE);

        println!("Bread gallery builder {}\nrun with -h for help", version);
        println!("config file: {}", confile);

        let buf = read_file(confile)
            .unwrap_or("{}".to_string());

        let config: AppConfig = serde_json::from_str(&buf)?;

        let _ = logging::init(&config.logging, &argv, None);
        config
    };

    let mut ginfo = {
        let cwd = env::current_dir()?;
        let web_path = cwd.join("web");
        let data_path = web_path.join("data");
        let tpl_path = web_path.join("templates");
        let thumbs_path = web_path.join("thumbs");

        GalleryInfo {
            web_path,
            data_path,
            tpl_path,
            thumbs_path,
            base_url: appcfg.web_url.clone(),
            templates: HashMap::new(),
            image_hashes: HashDict::load(cwd.join(".hashes.txt"))?,
            latest_year: 0,
            oldest_year: 0,
        }
    };

    let mut bread_dirs: Vec<DirEntry> = fs::read_dir(&ginfo.data_path)?
        .filter_map(Result::ok)
        .collect();

    bread_dirs.sort_by(|x, y| {
        x.file_name().cmp(&y.file_name())
    });

    let mut breads: Vec<Bread> = bread_dirs
        .iter()
        .filter_map(|p| Bread::parse(&ginfo.web_path, &p).ok())
        .collect();

    ginfo.latest_year = breads.last().unwrap().date.year();
    ginfo.oldest_year = breads.first().unwrap().date.year();

    for i in 0..breads.len() {
        let preceding = if i <= 0 { None } else {
            match breads.get(i - 1) {
                Some(b) => Some(b.to_link()),
                None => None
            }
        };

        let following = match breads.get(i + 1) {
            Some(b) => Some(b.to_link()),
            None => None
        };

        let cur = breads.get_mut(i).unwrap();

        cur.compile(&mut ginfo, preceding, following)?;
    }

    let mut channel: rss::Channel = rss::ChannelBuilder::default()
        .title("Piggo's Bread Gallery")
        .link("https://www.ondrovo.com/bread")
        .description("Sourdough feed")
        .build()
        .unwrap();

    ginfo.image_hashes.save();

    // rss
    {
        let start = (breads.len() as i32 - 10).max(0) as usize;
        let mut channel_items = vec![];
        for b in &mut breads[start..] {
            channel_items.push(b.rendered.rss_item.take().unwrap());
        }

        info!("Generating feed...");
        let f = OpenOptions::new()
            .write(true)
            .truncate(true)
            .create(true)
            .open(ginfo.web_path.join("feed.xml"))
            .unwrap();

        channel.set_items(channel_items);
        channel.pretty_write_to(f, b' ', 2).unwrap();
    }

    // main page
    {
        // make thumbs go from the newest to the oldest
        breads.reverse();

        let oldest = ginfo.oldest_year;
        let latest = ginfo.latest_year;
        let base_url = ginfo.base_url.clone();
        let year_pager = |year| {
            let mut buf = String::new();
            for y in oldest..=latest {
                if year == y {
                    buf.push_str(&format!("    <li class=\"active\"><a href=\"#\">{y}</a>\n", y=y));
                } else {
                    if y == latest {
                        buf.push_str(&format!("    <li><a href=\"{u}/index.html\">{y}</a>\n", u=base_url, y=y));
                    } else {
                        buf.push_str(&format!("    <li><a href=\"{u}/{y}.html\">{y}</a>\n", u=base_url, y=y));
                    }
                }
            }
            buf
        };

        for (year, year_breads) in &breads.iter().group_by(|b| b.date.year()) {
            let mut thumbs_buf = String::new();
            for b in year_breads {
                thumbs_buf.push_str(&b.rendered.thumb);
            }

            info!("Building the gallery page");

            let head = ginfo.template("_head.html")?
                .replace("{title}", "Piggo's breads");

            let main = ginfo.template("index.html")?
                .replace("{breads}", thumbs_buf.trim())
                .replace("{year_pager}", year_pager(year).trim())
                .replace("{head}", head.trim());

            let fname = if year == ginfo.latest_year {
                "index.html".to_string()
            } else {
                format!("{}.html", year)
            };

            let mut f = OpenOptions::new()
                .write(true)
                .truncate(true)
                .create(true)
                .open(ginfo.web_path.join(fname))
                .unwrap();

            f.write(main.as_bytes()).unwrap();
        }


    }

    Ok(())
}

pub fn read_file<P: AsRef<Path>>(path: P) -> io::Result<String> {
    let path = path.as_ref();
    let mut file = File::open(path)?;

    let mut buf = String::new();
    file.read_to_string(&mut buf)?;
    Ok(buf)
}