// #[allow(dead_code, unused)]

// vigyazz6! autoplayer
//
// This is a program automagically playing a card game called "Vigyazz6!".
//
// The rules are rather simple, but I'mrather lazy to reprint it in detail,
// so it'll be brief.
// 
// The code is based on a deck of 104 numbered cards, all of them having
// a face `value` and punishment `points` (the less the better).
// There are 2 to 10 players (but above 8 the code shall be modified to
// deal less cards), and the game has 5 rows of maximum 5 cards on the
// table. 
// All players throw cards at once, and they are put in the row with 
// closest less value; if there is none, they have to pick and take
// any row. When a row is full (5) they have to take the row and their
// card starts a new row head.
// When players are out of cards the least points collected wins.
//
// Important: I do not use `unsafe` code, this is all tightly controlled.
//

/// We use panic in several places where the code shall not go. 
use core::panic;
/// `VecDeque` is a Vec which can be pushed/popped at both ends
/// `time::Instant` is used to measure running time.
/// `cmp::Reverse` used for reverse sorting.
use std::{collections::VecDeque, time::Instant, cmp::Reverse};

/// We use this `pretty_env_logger` as a logging framework.
extern crate pretty_env_logger;
#[macro_use] extern crate log;

// I import structures from my module files to use here.
use crate::{deck::Deck, player::{Player, PlayerCard}, table::Table};

// Here we read the files and "get to know" what's in them. This isn't including, only scanning.
mod deck;
mod table;
mod player;
mod card;
mod row;

// We play this many game rounds. You want to keep this under 3 for any debug level above "warnings".
const GAME_ROUNDS: i32 = 100_000;

fn main() {
    // Env variable makes the logger to log more or less:
    // RUST_LOG=debug cargo run
    pretty_env_logger::init();
    info!("Program starting."); // info level logging
    game();
    info!("End of run.");
}


/*** Game ****/

/// `GameStat` structure collects global statistics about the run.
struct GameStat {
    game_count: i64,
    shuffle_count: i64,
    start_time: Instant, // use start_time.elapsed().as_nanos() or .as_secs()
}

/// Play all the game rounds.
fn game() {
    // Whole game statistics stored here
    let mut stats = GameStat { game_count:0, shuffle_count: 0, start_time: Instant::now() };

    // Create the game deck with all the card (ordered). Open box. Remove shrink wrap. :-)
    let mut deck = Deck::new();

    // Create the players (up to 8 w/o changing the hand cards)
    let player_names = vec![ "peter", "moni", "icbalint", "orsi", "topi", "kgb", "zsu", "csilla" ];
    // Iterate on player names, create Player struct from them and collect them into a Vec'tor.
    // (On the borrow level we don't consume the player_names vector [using `iter()` instead of `into_iter()`].)
    let mut players: Vec<Player> = player_names.iter().map( |n| Player::new(n.to_string()) ).collect();

    // We use this often, so take it now.
    let player_count = players.len(); // = <number of players> - 1

    // Start playing - GAME_ROUNDS rounds.
    for cnt_game in 1..=GAME_ROUNDS {
        debug!("Game round {} starts", cnt_game); // debug level logging
        // Shuffle the deck (using various methods)
        deck.shuffle();
        stats.shuffle_count += 1;
        stats.game_count += 1;

        // dealing 10 cards for each player
        debug!("Dealing.");
        for _i in 1..=10 {
            for player in 0 .. player_count {
                players[player].get_card( deck.pop().expect("Deck is empty while dealing to players") );
            }
        }

        // we need 5 cards from deck to build the rows
        debug!("Building the rows.");
        let mut cards = VecDeque::new();
        // This is another way to write "for _ in (1..=5) { ... }"
        (1..=5).for_each(|_| {
            cards.push_back( deck.pop().expect("deck empty before starting the game") );
        });
        trace!("We pushed 5 cards to rows: {:?}\n", cards);

        // Create the Table (contains the Deck, the Rows (with 5 starting `cards`) and occasional cards thrown by Players)
        let mut table = Table::new(cards);

/*      debug!("Table: {:?}\n", table);
        debug!("Players: {:?}\n", players);
        debug!("Deck: {:?}\n", deck);
 */        
        debug!("We have the table ready: {:?}", table);

        // playing one game, players taking turns
        debug!("Players start taking turns");
        // Since players have 10 cards dealt we have exactly 10 turns.
        for turn in 1..=10 {
            debug!("Turn {}!", turn);
            trace!("The table: {:?}", table);

            // Everyone puts a card "face down" (Rust promised not to peek).
            // If I used the `players.for_each()` form I would hit the borrow checker:
            // `players` would be repeatedly borrowed mutable and program wouldn't compile.
            for player in 0 .. player_count {
                // get a card from the player
                let player_id: i32 = player.try_into().unwrap();    // convert `usize` array index into `i32` [that was an unnecessary hassle: in fact I should rewrite this using usize everywhere]
                let topcard = players[player].throw_card();         // If Player [module] was smart this would be a chosen card, but it would need player
                                                                    // not just brains but possibility to peek at the rows. This wasn't in the plan, so 
                                                                    // we just take the top card in hand.
                // put it on the table ("turned face down")
                table.lay_player_card( topcard, player_id );        // We actually move the card variable with its ownership everywhere, so no &refs.
            }

            // Process cards on the Table.
            debug!("The Table process the throws.");
            // Sort the cards by `value` the players have thrown.
            table.sort_cards();

            // Pick them one by one, from smallest to larger ones
            while table.has_player_cards() {
                let smallest: PlayerCard = table.get_smallest_player_card(); // I just wrote the PlayerCard type to show; Rust is smart enough to know.
                trace!("Take smallest card {:?}", &smallest);

                // Find the row with the closest smallest card, or None if smaller than any row head.
                let closest_row = table.get_closest_row(&smallest); // That is an Option<usize>.
                trace!("Choose closest row: {:?}", closest_row);

                match closest_row {
                    Some(rowid) => {
                        // We have to put it at the end of `rowid`.
                        debug!("Putting down card into row {}", rowid);
                        let player_id: usize = smallest.player_id.try_into().unwrap(); // By "just" indexing `players` (by `player_id`) I have avoided borrowing it and get into trouble later.
                        // Try to put the card to the end of the row, or collect full row first
                        let overflow = table.put_card_into_row(smallest, rowid); // And this is Option<VecDeque<Card>>.
                        if let Some(cards) = overflow {
                            // Row is full, we got pile ("bust")
                            debug!("Row is busted, {} collects", players[player_id].get_name());    
                            // Player gets pile, thrown card was put into row head
                            players[ player_id ].give_pile( cards );
                        }
                    },
                    None => {
                        // Card too small, need to pick any row to take!
                        let player_id: usize = smallest.player_id.try_into().unwrap(); // We _directly_ access `PlayerCard.player_id` structure member, because borrow checker wasn't helping my mental hygiene.
                        debug!("Too small from {}, picking row", players[player_id].get_name());
                        // Pick any row to take
                        let rowid = players[ player_id ].pick_row_for_small_card(table.peek_rows(), &smallest.card);
                        trace!("Picked row {}", rowid);
                        // take the row cards ("bust")
                        let cards = table.take_row(rowid);
                        trace!("Took cards: {:?}", cards);
                        // and give them to the player who owns the card
                        players[ player_id ].give_pile( cards );
                        // put new card in the row
                        let overflow = table.put_card_into_row(smallest, rowid);
                        if let Some(_) = overflow {
                            // If this fires then I have fucked something up. :-)
                            panic!("Player took whole row and it's already full");
                        }
                    }
                }
            }
        }

        // end of round
        info!("Round finished, len is {} ??sec", stats.start_time.elapsed().as_micros());

        debug!("End of round, counting and collecting back piles");
        // We collect the winner(s) and their score here
        let mut winners: Vec<usize> = Vec::new();
        let mut winscore: i32 = i32::MAX-1; // Getting facy here about "larger than any valid value".

        for i in 0..player_count {
            info!("Player {} has {} points", players[i].get_name(), players[i].get_points());

            if players[i].get_points() < winscore  {
                trace!("New winner {} with score {}", players[i].get_name(), players[i].get_points());
                winners.clear();
                winners.push(i);
                winscore = players[i].get_points();
            
            } else if players[i].get_points() == winscore {
                trace!("New co-winner {} with score {}", players[i].get_name(), players[i].get_points());
                winners.push(i);
            }
            trace!("The list of winners is {:?}", winners);

            // get pile from Player
            let cards = players[i].get_pile();
            // and give it back to the Deck
            deck.push_cards(cards);
            // close Player round and update stats
            players[i].close_round();
        }

        // collect remaining Cards from Table
        deck.push_cards( table.collect_rows() );
        trace!("Shall have full deck now, len {}", deck.len());

        // This is a Vec of `player_id`s, i is a &ref
        for i in winners.iter() {
            players[*i].inc_wins(); // Increment win count of &Vec<usize> player_id
        }

        // Collect the names of the winners.
        let mut finals = Vec::new();
        for i in winners {
            finals.push( players[i].get_name() );
        }
        info!("The winner(s): {:?}", &finals);
    }

    // Do the type conversions _very_ visibly. `as_micros()` results `u128`
    let elapsed_micro: f64 = stats.start_time.elapsed().as_micros() as f64;
    // and `GAME_ROUNDS` is `i32`. We'll use `elapsed_micro/game_rounds` later.
    let game_rounds: f64 = GAME_ROUNDS.into();
    // ???which is same as the slightly uglier:
    let _res: f64 = stats.start_time.elapsed().as_micros() as f64 / <i32 as Into<f64>>::into(GAME_ROUNDS);

    println!("Totals (game time {} ??s, or {} s; {} ??s/game), {} games played ({} shuffles):", 
        stats.start_time.elapsed().as_micros(), 
        stats.start_time.elapsed().as_secs(),
        elapsed_micro / game_rounds, 
        stats.game_count,
        stats.shuffle_count,
    );

    // players.sort_by( |a, b| a.total_point.partial_cmp(&b.total_point).unwrap() );    // ASC points
    // players.sort_by( |a, b| b.wins.partial_cmp(&a.wins).unwrap() );                  // DESC wins
    players.sort_by_cached_key( |x| Reverse(x.get_wins()) );                            // DESC wins (caching is just for the show); using std::cmp::Reverse

    // Print out totals
    for i in 0..players.len() {
        let p = &players[i]; // the rest looks simpler by using this. (Seems to confuse rust-analyzer in codium though.)
        println!("Player {} has wins {}, score {} (busted {} times)", 
            p.get_name(), 
            p.get_wins(), 
            p.get_total_points(), 
            p.get_rows_busted());
    }
}

// Tests. Try `cargo test`. 
// They have criminally low coverage, mostly due to the simplicity of the code.
// Take it as some examples. 
#[cfg(test)]
mod tests {
    use std::collections::VecDeque;
    use rand::Rng;

    use crate::{card::Card, player::{Player, PlayerCard}, row::Row, table::Table};

    #[test]
    /// Test Card, and point generation logic.
    fn card_values() {
        let card_values = vec![1,2,5,10,33,55,77];
        let card_points = vec![1,1,2,3, 5, 7, 5];
        for i in 1 .. card_values.len() {
            let c = Card::new( card_values[i] );
            let p = c.points;
            assert!(p == card_points[i], "card={} card points={} i={} expected point={}", card_values[i], p, i, card_points[i]);
        }
    }

    #[test]
    fn player_take_pile() {
        // create a player
        let mut p = Player::new("bob".to_string());
        // create a pile
        let mut pile = VecDeque::new();
        let mut refpile = VecDeque::new();
        for i in 5..10 {
            let c = Card::new(i);
            pile.push_back(c);
            let c = Card::new(i);
            refpile.push_back(c);
        }
        // give the pile to player
        p.give_pile(pile);
        assert!( p.get_rows_busted() == 1 );

        // get back the pile from player
        // p = p.gimme_pile();
        let pile = p.get_pile();
        
        // the pile we got shall be same as the pile we gave
        // this check is O(n^2), doesn't matter for less than 100 items
        assert_eq!( pile, refpile );
        assert!( pile.iter().all( |item| refpile.contains(item)) );

        let mut pile = VecDeque::new();
        for i in 4..=9 {
            let c = Card::new(i);
            pile.push_back(c);
        }
        p.give_pile(pile);
        assert!( p.get_rows_busted() == 2 );
    }

    #[test]
    fn row_push() {
        let mut row = Row::new();
        let mut refcard = VecDeque::new();   // reference vec to check
        for i in 1..=7 {
            let cval = i+5;
            let card = Card::new(cval);
            // push a card into the row
            if let Some(cards) = row.push_or_collect(card) {
                // got the overflow
                println!("Got overflow row at {}!", i);
                assert!( i == 6, "Overflow at wrong position: {} != 6", i );
                // we need to get the proper vec
                assert!( cards.iter().all( |item| refcard.contains(item) ), "Got cards {:?}", cards ); 
            } else {
                println!("push success {}", i);
            }
            // remember the correct vec for checking
            let card = Card::new(cval);
            refcard.push_back(card);

            // check card value
            assert!( row.last_card_value() == cval, "Last card value mismatch: got {} vs expected {}", row.last_card_value(), cval );
        }
        assert!( row.len() == 2, "Row contains wrong amount of cards: {}", row.len() );
    }

    #[test]
    fn sort_cards() {
        let mut cards: VecDeque<Card> = VecDeque::new();
        let mut rng = rand::thread_rng();
        for _ in 1..50 {
            let n = rng.gen_range(1..104);
            cards.push_back( Card::new(n) );
        }
        cards.make_contiguous().sort();

        for i in 1..cards.len() {
            assert!( cards[i-1].value <= cards[i].value, "Bad ordering: {} > {}", cards[i-1].value,cards[i].value );
        }
    }

    #[test]
    fn check_closest_row() {
        let table = generate_table();
        let pcard = PlayerCard{ player_id: 42, card: Card::new(42) };
        let closest = table.get_closest_row(&pcard);
        assert_eq!( closest, Some(3) ); // index from 0
    }

    #[test]
    fn check_smallest_player_card() {
        let mut table = generate_table();
        
        let mut player_id = 1;
        vec![103, 8, 71, 93, 6].into_iter().for_each(|c| {
            table.lay_player_card( Card::new(c), player_id);
            player_id += 1;
        });

        let smallest = table.get_smallest_player_card();
        assert_eq!( smallest, PlayerCard{ player_id: 5, card: Card::new(6) } );
    }

    fn generate_table() -> Table  {
        let mut row_cards = VecDeque::new();
        vec![5,7,10,33,70].into_iter().for_each(|c| row_cards.push_back( Card::new(c) ));
        let table = Table::new(row_cards);
        table
    }
}