commit adfa99149e9ff84502092fff9b7f52866929161c
Author: landrigun <manach.r@msn.com>
Date:   Sat Nov 12 14:16:12 2022 +0000

    first tic-tac-toe implementation

diff --git a/.gitignore b/.gitignore
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--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/target
+tic-tac-toe
diff --git a/Cargo.lock b/Cargo.lock
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+++ b/Cargo.lock
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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "tic-tac-toe"
+version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
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+++ b/Cargo.toml
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+[package]
+name = "tic-tac-toe"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/README.md b/README.md
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+++ b/README.md
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+# Tic-Tac-Toe
+
+A simple Rust implementation of the famous game: **Tic-Tac-Toe**
+
+## Build
+```bash
+cargo build --release
+```
+
+## Run
+```bash
+./tic-tac-toe
+```
diff --git a/src/main.rs b/src/main.rs
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index 0000000..e73bb04
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+++ b/src/main.rs
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+use std::str::FromStr;
+
+/// Represents the `item` on the TTT board (X or O)
+#[derive(Copy, Clone, Debug, PartialEq)]
+enum Item {
+    X,
+    O,
+    Empty,
+}
+
+impl Into<String> for Item {
+    fn into(self) -> String {
+        match self {
+            Self::X => "X".to_string(),
+            Self::O => "O".to_string(),
+            Self::Empty => "_".to_string(),
+        }
+    }
+}
+
+impl TryFrom<String> for Item {
+    type Error = String;
+    fn try_from(item: String) -> Result<Self, Self::Error> {
+        match &item[..] {
+            "X" | "x" => Ok(Self::X),
+            "O" | "o" => Ok(Self::O),
+            _ => Err("unknown item, retry!".to_string()),
+        }
+    }
+}
+
+/// Two `GameType` availables:
+/// * TwoPlayers: no bot
+/// * Bot: player against the bot
+enum GameType {
+    TwoPlayers,
+    Bot,
+    Unknown,
+}
+
+impl From<String> for GameType {
+    fn from(game_type: String) -> Self {
+        match &game_type[..] {
+            "0" => Self::TwoPlayers,
+            "1" => Self::Bot,
+            _ => Self::Unknown,
+        }
+    }
+}
+
+/// In order to visualize the board game
+trait Displayer {
+    fn show(&self);
+}
+
+/// Represents the **Tic-Tac-Toe** board game
+struct Board {
+    // board array is reprensented as follow:
+    // [ 0, 1, 2 ]
+    // [ 3, 4, 5 ]
+    // [ 6, 7, 8 ]
+    items: [Item; 9],
+}
+
+impl Board {
+    fn new() -> Board {
+        Board {
+            items: [Item::Empty; 9],
+        }
+    }
+
+    fn base_display(group_items: Vec<String>) {
+        // output:       X   |   _   |   O
+        println!(
+            "{}",
+            format!(
+                "{:<5} {} {:<2}|{:<2} {} {:<2}|{:<2} {}",
+                "", group_items[0], "", "", group_items[1], "", "", group_items[2]
+            )
+        );
+    }
+
+    /// checks whether the board is item's full (quit the game)
+    fn is_full(&self) -> bool {
+        for item in self.items {
+            match item {
+                Item::Empty => return false,
+                _ => continue,
+            };
+        }
+        true
+    }
+
+    fn set_item(&mut self, item: Item, pos: String) -> Result<usize, &str> {
+        let idx = if let Ok(v) = usize::from_str(&pos) {
+            v
+        } else {
+            return Err("unable to parse the input, retry!");
+        };
+        if idx == 0 || idx > 9 {
+            return Err("can't be greater than 8");
+        }
+        match self.items[idx - 1] {
+            Item::X => Err("already set, choose another one!"),
+            Item::O => Err("already set, choose another one!"),
+            Item::Empty => {
+                self.items[idx - 1] = item;
+                return Ok(idx - 1);
+            }
+        }
+    }
+
+    fn check_first_line(&self, item: Item) -> bool {
+        self.items[0] == item && self.items[1] == item && self.items[2] == item
+    }
+
+    fn check_second_line(&self, item: Item) -> bool {
+        self.items[3] == item && self.items[4] == item && self.items[5] == item
+    }
+
+    fn check_last_line(&self, item: Item) -> bool {
+        self.items[6] == item && self.items[7] == item && self.items[8] == item
+    }
+
+    fn check_first_col(&self, item: Item) -> bool {
+        self.items[0] == item && self.items[3] == item && self.items[6] == item
+    }
+
+    fn check_second_col(&self, item: Item) -> bool {
+        self.items[1] == item && self.items[4] == item && self.items[7] == item
+    }
+
+    fn check_last_col(&self, item: Item) -> bool {
+        self.items[2] == item && self.items[5] == item && self.items[8] == item
+    }
+
+    fn check_first_diag(&self, item: Item) -> bool {
+        self.items[0] == item && self.items[4] == item && self.items[8] == item
+    }
+
+    fn check_last_diag(&self, item: Item) -> bool {
+        self.items[2] == item && self.items[4] == item && self.items[6] == item
+    }
+
+    /// instead of scanning all the board, checks input "win" combinaison
+    fn check_win(&self, item: Item, idx: usize) -> bool {
+        match idx {
+            0 => {
+                self.check_first_col(item)
+                    || self.check_first_line(item)
+                    || self.check_first_diag(item)
+            }
+            1 => self.check_first_line(item) || self.check_second_col(item),
+            2 => {
+                self.check_first_line(item)
+                    || self.check_last_col(item)
+                    || self.check_last_diag(item)
+            }
+            3 => self.check_first_col(item) || self.check_second_line(item),
+            4 => {
+                self.check_second_col(item)
+                    || self.check_second_line(item)
+                    || self.check_last_diag(item)
+                    || self.check_first_diag(item)
+            }
+            5 => self.check_last_col(item) || self.check_second_line(item),
+            6 => {
+                self.check_first_col(item)
+                    || self.check_last_line(item)
+                    || self.check_last_diag(item)
+            }
+            7 => self.check_last_line(item) || self.check_second_col(item),
+            8 => {
+                self.check_last_line(item)
+                    || self.check_last_col(item)
+                    || self.check_first_diag(item)
+            }
+            _ => false,
+        }
+    }
+}
+
+impl Displayer for Board {
+    /// loops over board items, groups items by 3 (multi dim array representation) and display it
+    /// also displays board index number (empty item) for easy use
+    fn show(&self) {
+        println!("\n");
+        println!("{:<3}{:-<23}", "", "");
+
+        let mut group_items: Vec<String> = vec![];
+        let items: Vec<String> = self
+            .items
+            .iter()
+            .enumerate()
+            .map(|(idx, x)| {
+                if x != &Item::Empty {
+                    Into::<String>::into(*x)
+                } else {
+                    format!("{}", idx + 1)
+                }
+            })
+            .collect();
+        for item in items {
+            group_items.push(item.clone());
+            if group_items.len() != 3 {
+                continue;
+            }
+            Board::base_display(group_items.clone());
+            group_items.clear();
+            println!("{:<3}{:-<23}", "", "");
+        }
+
+        println!("\n");
+    }
+}
+
+#[allow(dead_code)]
+struct TicTacToe {
+    board: Board,
+    current_item: Item,
+    game_type: GameType,
+    turn: u8,
+}
+
+impl Default for TicTacToe {
+    fn default() -> Self {
+        TicTacToe {
+            board: Board::new(),
+            game_type: GameType::Bot,
+            current_item: Item::Empty,
+            turn: 1,
+        }
+    }
+}
+
+impl TicTacToe {
+    fn get_user_input(message: &str) -> String {
+        info(message.to_string());
+        let mut input = String::new();
+        std::io::stdin()
+            .read_line(&mut input)
+            .expect("IO error: unable to read the stdin input");
+        input.trim().to_string()
+    }
+
+    fn set_current_item(&mut self, item: Item) {
+        self.current_item = item;
+    }
+
+    /// tries to get the first item (the one that starts)
+    fn select_current_item(&mut self) {
+        let mut attempt = 0;
+        loop {
+            if attempt == 2 {
+                error("come on... you can do better!".to_string());
+                std::process::exit(1);
+            }
+
+            let item_start =
+                TicTacToe::get_user_input("first player, choose your item: ('X' or 'O')");
+            let item = Item::try_from(item_start);
+            match item {
+                Ok(i) => {
+                    self.set_current_item(i);
+                    break;
+                }
+                Err(e) => error(e.to_string()),
+            }
+            attempt += 1;
+        }
+    }
+
+    /// on each turn, set the next item who has to play
+    fn next_item(&mut self) {
+        match self.current_item {
+            Item::X => self.set_current_item(Item::O),
+            Item::O => self.set_current_item(Item::X),
+            _ => return,
+        }
+        self.turn += 1;
+    }
+
+    fn run(&mut self) {
+        self.select_current_item();
+        self.board.show();
+
+        loop {
+            if self.board.is_full() {
+                info("game over!".to_string());
+                self.board.show();
+                break;
+            }
+
+            let item_icon: String = self.current_item.into();
+            let turn_message = format!(
+                "{} turn, which case do you wan to fill ?",
+                item_icon.clone()
+            );
+            let idx = TicTacToe::get_user_input(&turn_message);
+            match self.board.set_item(self.current_item.clone(), idx) {
+                Ok(i) => {
+                    // no need to check for a winner until the turn 5
+                    if self.turn > 4 && self.board.check_win(self.current_item.clone(), i) {
+                        info(format!("{} wins!", item_icon.clone()));
+                        self.board.show();
+                        break;
+                    }
+                }
+                Err(e) => {
+                    error(e.to_string());
+                    continue;
+                }
+            }
+
+            self.next_item();
+            self.board.show();
+        }
+    }
+}
+
+fn info(msg: String) {
+    println!("{}", format!("[TIC TAC TOE] [INFO] => {}", msg))
+}
+
+fn error(msg: String) {
+    eprintln!("{}", format!("[TIC TAC TOE] [ERROR] => {}", msg))
+}
+
+fn main() {
+    let mut game = TicTacToe::default();
+    game.run();
+}