#[macro_use]
extern crate criterion;

use criterion::Criterion;
use std::collections::HashMap;
use std::fs::read_to_string;
use std::time::{Duration, Instant};
use tokenizers::models::unigram::Unigram;
use tokenizers::models::unigram::UnigramTrainer;

pub fn bench_train(c: &mut Criterion) {
    let trainer = UnigramTrainer::builder()
        .show_progress(false)
        .unk_token(Some("<UNK>".into()))
        .build()
        .unwrap();

    let mut model = Unigram::default();

    let content = read_to_string("data/small.txt").unwrap();
    let mut word_counts = HashMap::new();
    content.split_whitespace().for_each(|word| {
        // This is important for the test of char vs u8
        let word = format!("▁{}", word);
        *word_counts.entry(word).or_insert(0) += 1;
    });

    let sentences: Vec<_> = word_counts
        .iter()
        .map(|(s, i)| (s.to_owned(), *i))
        .collect();

    c.bench_function("Unigram Train vocabulary (small)", |b| {
        b.iter_custom(|iters| {
            let mut duration = Duration::new(0, 0);
            for _i in 0..iters {
                let sentences = sentences.clone();
                let start = Instant::now();
                trainer.do_train(sentences, &mut model).unwrap();
                duration = duration.checked_add(start.elapsed()).unwrap();
            }
            duration
        })
    });

    let content = read_to_string("data/big.txt").unwrap();
    // creating `medium` data, which is the first 25% of `data/big.txt`
    let content = String::from(&content[..(content.len() as f64 * 0.25) as usize]);
    let mut word_counts = HashMap::new();
    content.split_whitespace().for_each(|word| {
        // This is important for the test of char vs u8
        let word = format!("▁{}", word);
        *word_counts.entry(word).or_insert(0) += 1;
    });

    let sentences: Vec<_> = word_counts
        .iter()
        .map(|(s, i)| (s.to_owned(), *i))
        .collect();

    c.bench_function("Unigram Train vocabulary (medium)", |b| {
        b.iter_custom(|iters| {
            let mut duration = Duration::new(0, 0);
            for _i in 0..iters {
                let sentences = sentences.clone();
                let start = Instant::now();
                trainer.do_train(sentences, &mut model).unwrap();
                duration = duration.checked_add(start.elapsed()).unwrap();
            }
            duration
        })
    });
}

criterion_group! {
    name = benches_train;
    config = Criterion::default().sample_size(10);
    targets = bench_train
}

criterion_main!(benches_train);
