// TODO make the raptor binary expose multiple subcommand
//      make only one binary

extern crate raptor;
extern crate rocksdb;
extern crate serde_json;
#[macro_use] extern crate serde_derive;
extern crate unidecode;
extern crate moby_name_gen;

use std::path::Path;
use std::collections::{HashSet, BTreeMap};
use std::fs::{self, File};
use std::io::{self, BufReader, BufRead};
use std::iter;

use raptor::{MetadataBuilder, Metadata, DocIndex};
use rocksdb::{SstFileWriter, EnvOptions, ColumnFamilyOptions};
use serde_json::from_str;
use unidecode::unidecode;

#[derive(Debug, Deserialize)]
struct Product {
    title: String,
    product_id: u64,
    ft: String,
}

fn set_readonly<P>(path: P, readonly: bool) -> io::Result<()>
where P: AsRef<Path>
{
    let mut perms = fs::metadata(&path)?.permissions();
    perms.set_readonly(readonly);
    fs::set_permissions(&path, perms)
}

fn is_readonly<P: AsRef<Path>>(path: P) -> io::Result<bool> {
    fs::metadata(&path).map(|m| m.permissions().readonly())
}

fn main() {
    let data = File::open("products.json_lines").unwrap();
    let data = BufReader::new(data);

    let common_words = {
        match File::open("fr.stopwords.txt") {
            Ok(file) => {
                let file = BufReader::new(file);
                let mut set = HashSet::new();
                for line in file.lines().filter_map(|l| l.ok()) {
                    for word in line.split_whitespace() {
                        set.insert(word.to_owned());
                    }
                }
                set
            },
            Err(e) => {
                eprintln!("{:?}", e);
                HashSet::new()
            },
        }
    };

    // TODO add a subcommand to pack these files in a tar.xxx archive
    let random_name = moby_name_gen::random_name();
    let map_file = format!("{}.map", random_name);
    let idx_file = format!("{}.idx", random_name);
    let sst_file = format!("{}.sst", random_name);

    for file in &[&map_file, &idx_file, &sst_file] {
        match is_readonly(file) {
            Ok(true) => panic!("the {:?} file is readonly, please make it writeable", file),
            Err(ref e) if e.kind() == io::ErrorKind::NotFound => (),
            Err(e) => panic!("{:?}", e),
            Ok(false) => (),
        }
    }

    let env_options = EnvOptions::new();
    let cf_options = ColumnFamilyOptions::new();
    let mut sst_file_writer = SstFileWriter::new(env_options, cf_options);
    sst_file_writer.open(&sst_file).expect("open the sst file");

    let map = File::create(&map_file).unwrap();
    let indexes = File::create(&idx_file).unwrap();
    let mut builder = MetadataBuilder::new(map, indexes);
    let mut fields = BTreeMap::new();

    for line in data.lines() {
        let line = line.unwrap();

        let product: Product = from_str(&line).unwrap();

        {
            let title = iter::repeat(0).zip(product.title.split_whitespace()).filter(|&(_, w)| !common_words.contains(w)).enumerate();
            let description = iter::repeat(1).zip(product.ft.split_whitespace()).filter(|&(_, w)| !common_words.contains(w)).enumerate();

            let words = title.chain(description);
            for (i, (attr, word)) in words {
                let doc_index = DocIndex {
                    document: product.product_id,
                    attribute: attr,
                    attribute_index: i as u32,
                };
                // insert the exact representation
                let word_lower = word.to_lowercase();

                // and the unidecoded lowercased version
                let word_unidecoded = unidecode(word).to_lowercase();
                if word_lower != word_unidecoded {
                    builder.insert(word_unidecoded, doc_index);
                }

                builder.insert(word_lower, doc_index);
            }
        }

        // TODO simplify this by using functions and
        //      use the MetadataBuilder internal BTreeMap ?
        let key = format!("{}-title", product.product_id);
        let value = product.title;
        fields.insert(key, value);

        let key = format!("{}-description", product.product_id);
        let value = product.ft;
        fields.insert(key, value);
    }

    for (key, value) in fields {
        sst_file_writer.put(key.as_bytes(), value.as_bytes()).unwrap();
    }
    let sst_file_info = sst_file_writer.finish().unwrap();

    builder.finish().unwrap();

    println!("Succesfully created files: {}, {}, {}", map_file, idx_file, sst_file);

    set_readonly(&map_file, true).unwrap();
    set_readonly(&idx_file, true).unwrap();
    set_readonly(&sst_file, true).unwrap();

    println!("Checking the dump consistency...");
    unsafe { Metadata::from_paths(map_file, idx_file).unwrap() };
    // TODO do it better!
}