extern crate getopts;
#[macro_use]
extern crate log;
extern crate rand;
extern crate crossbeam;
extern crate fnv;

mod helpers;
mod game;
mod simulator;
mod strategy;
mod strategies {
    pub mod examples;
    pub mod cheating;
    pub mod information;
}

use getopts::Options;
use std::str::FromStr;

struct SimpleLogger;
impl log::Log for SimpleLogger {
    fn enabled(&self, metadata: &log::LogMetadata) -> bool {
        metadata.level() <= log::LogLevel::Trace
    }

    fn log(&self, record: &log::LogRecord) {
        if self.enabled(record.metadata()) {
            println!("{} - {}", record.level(), record.args());
        }
    }
}


fn print_usage(program: &str, opts: Options) {
    print!("{}", opts.usage(&format!("Usage: {} [options]", program)));
}


fn main() {
    let args: Vec<String> = std::env::args().collect();
    let program = args[0].clone();

    let mut opts = Options::new();
    opts.optopt("l", "loglevel",
                "Log level, one of 'trace', 'debug', 'info', 'warn', and 'error'",
                "LOGLEVEL");
    opts.optopt("n", "ntrials",
                "Number of games to simulate (default 1)",
                "NTRIALS");
    opts.optopt("o", "output",
                "Number of games after which to print an update",
                "OUTPUT_FREQ");
    opts.optopt("t", "nthreads",
                "Number of threads to use for simulation (default 1)",
                "NTHREADS");
    opts.optopt("s", "seed",
                "Seed for PRNG (default random)",
                "SEED");
    opts.optopt("p", "nplayers",
                "Number of players",
                "NPLAYERS");
    opts.optopt("g", "strategy",
                "Which strategy to use.  One of 'random', 'cheat', and 'info'",
                "STRATEGY");
    opts.optflag("h", "help",
                 "Print this help menu");
    opts.optflag("", "results-table",
                 "Print a table of results for each strategy");
    opts.optflag("", "write-results-table",
                 "Update the results table in README.md");
    let matches = match opts.parse(&args[1..]) {
        Ok(m) => { m }
        Err(f) => {
            print_usage(&program, opts);
            panic!(f.to_string())
        }
    };
    if matches.opt_present("h") {
        return print_usage(&program, opts);
    }
    if !matches.free.is_empty() {
        return print_usage(&program, opts);
    }
    if matches.opt_present("write-results-table") {
        return write_results_table();
    }
    if matches.opt_present("results-table") {
        return print!("{}", get_results_table());
    }

    let log_level_str : &str = &matches.opt_str("l").unwrap_or("info".to_string());
    let log_level = match log_level_str {
        "trace" => { log::LogLevelFilter::Trace }
        "debug" => { log::LogLevelFilter::Debug }
        "info"  => { log::LogLevelFilter::Info }
        "warn"  => { log::LogLevelFilter::Warn }
        "error" => { log::LogLevelFilter::Error }
        _       => {
            print_usage(&program, opts);
            panic!("Unexpected log level argument {}", log_level_str);
        }
    };

    log::set_logger(|max_log_level| {
        max_log_level.set(log_level);
        Box::new(SimpleLogger)
    }).unwrap();

    let n_trials = u32::from_str(&matches.opt_str("n").unwrap_or("1".to_string())).unwrap();
    let seed = matches.opt_str("s").map(|seed_str| { u32::from_str(&seed_str).unwrap() });
    let progress_info = matches.opt_str("o").map(|freq_str| { u32::from_str(&freq_str).unwrap() });
    let n_threads = u32::from_str(&matches.opt_str("t").unwrap_or("1".to_string())).unwrap();
    let n_players = u32::from_str(&matches.opt_str("p").unwrap_or("4".to_string())).unwrap();
    let strategy_str : &str = &matches.opt_str("g").unwrap_or("cheat".to_string());

    sim_games(n_players, strategy_str, seed, n_trials, n_threads, progress_info).info();
}

fn sim_games(n_players: u32, strategy_str: &str, seed: Option<u32>, n_trials: u32, n_threads: u32, progress_info: Option<u32>)
    -> simulator::SimResult {
    let hand_size = match n_players {
        2 => 5,
        3 => 5,
        4 => 4,
        5 => 4,
        _ => { panic!("There should be 2 to 5 players, not {}", n_players); }
    };

    let game_opts = game::GameOptions {
        num_players: n_players,
        hand_size: hand_size,
        num_hints: 8,
        num_lives: 3,
        // hanabi rules are a bit ambiguous about whether you can give hints that match 0 cards
        allow_empty_hints: false,
    };

    let strategy_config : Box<strategy::GameStrategyConfig + Sync> = match strategy_str {
        "random" => {
            Box::new(strategies::examples::RandomStrategyConfig {
                hint_probability: 0.4,
                play_probability: 0.2,
            }) as Box<strategy::GameStrategyConfig + Sync>
        },
        "cheat" => {
            Box::new(strategies::cheating::CheatingStrategyConfig::new())
                as Box<strategy::GameStrategyConfig + Sync>
        },
        "info" => {
            Box::new(strategies::information::InformationStrategyConfig::new())
                as Box<strategy::GameStrategyConfig + Sync>
        },
        _ => {
            panic!("Unexpected strategy argument {}", strategy_str);
        },
    };
    simulator::simulate(&game_opts, strategy_config, seed, n_trials, n_threads, progress_info)
}

fn get_results_table() -> String {
    let strategies = ["cheat", "info"];
    let player_nums = (2..=5).collect::<Vec<_>>();
    let seed = 0;
    let n_trials = 1;
    let n_threads = 8;

    let intro = format!("On the first {} seeds, we have these average scores and win rates:\n\n", n_trials);
    let format_name    = |x|  format!(" {:7} ",      x);
    let format_players = |x|  format!("   {}p    ",  x);
    let format_percent = |x|  format!(" {:05.2} % ", x);
    let format_score   = |x|  format!(" {:07.4} ",   x);
    let space          = String::from("         ");
    let dashes         = String::from("---------");
    type TwoLines = (String, String);
    fn make_twolines(player_nums: &Vec<u32>, head: TwoLines, make_block: &dyn Fn(u32) -> TwoLines) -> TwoLines {
        let mut blocks = player_nums.iter().cloned().map(make_block).collect::<Vec<_>>();
        blocks.insert(0, head);
        fn combine(items: Vec<String>) -> String {
            items.iter().fold(String::from("|"), |init, next| { init + next + "|" })
        }
        let (a, b): (Vec<_>, Vec<_>) = blocks.into_iter().unzip();
        (combine(a), combine(b))
    }
    fn concat_twolines(body: Vec<TwoLines>) -> String {
        body.into_iter().fold(String::default(), |output, (a, b)| (output + &a + "\n" + &b + "\n"))
    }
    let header = make_twolines(&player_nums, (space.clone(), dashes.clone()), &|n_players| (format_players(n_players), dashes.clone()));
    let mut body = strategies.iter().map(|strategy| {
        make_twolines(&player_nums, (format_name(strategy), space.clone()), &|n_players| {
            let simresult = sim_games(n_players, strategy, Some(seed), n_trials, n_threads, None);
            (format_score(simresult.average_score()), format_percent(simresult.percent_perfect()))
        })
    }).collect::<Vec<_>>();
    body.insert(0, header);
    intro + &concat_twolines(body)
}

fn write_results_table() {
    let separator = r#"
## Results (auto-generated)

To reproduce:
```
time cargo run --release -- --results-table
```

To update this file:
```
time cargo run --release -- --write-results-table
```

"#;
    let readme = "README.md";
    let readme_contents = std::fs::read_to_string(readme).unwrap();
    let readme_init = {
        let parts = readme_contents.splitn(2, separator).collect::<Vec<_>>();
        if parts.len() != 2 {
            panic!("{} has been modified in the Results section!", readme);
        }
        parts[0]
    };
    let table = get_results_table();
    let new_readme_contents = String::from(readme_init) + separator + &table;
    std::fs::write(readme, new_readme_contents).unwrap();
}