# Minesweeper

A console Minesweeper for the terminal, built on .NET 10. The rules live in a UI-free engine, so
the same board can be driven by the console client or by tests.

```
9x9  mines left 10  flags 0/10  time 12s
Reveal every cell that is not a mine.

     A  B  C  D  E  F  G  H  I
  1  #  #  1  ·  ·  1  #  #  #
  2  1  1  1  ·  ·  1  1  2  1
  3  ·  ·  ·  ·  ·  ·  ·  ·  ·
  4  2  2  1  ·  ·  ·  ·  ·  ·
  5  #  #  1  ·  ·  ·  ·  ·  ·
  6  #  #  2  1  2  1  1  ·  ·
  7  #  #  #  #  #  #  2  2  2
  8  #  #  #  #  #  #  #  #  #
  9  #  #  #  #  #  #  #  #  #

type "<row> <col>" to reveal, f <row> <col> to flag, ? for help, q to quit
>
```

## Play it

```bash
dotnet run --project src/Minesweeper.Cli
```

| Option | Meaning |
| --- | --- |
| `-d, --difficulty <beginner\|intermediate\|expert>` | board preset (default: beginner) |
| `-b`, `-i`, `-e` | shorthand for the three presets |
| `-k, --keys` | arrow-key play instead of typed commands |
| `--seed <n>` | deterministic mines, for reproducible games |
| `-h, --help` | usage, command list, and legend |

Beginner is 9x9 with 10 mines, intermediate 16x16 with 40, expert 30x16 with 99.

## Commands

Rows are numbered `1..N` down the left, columns are lettered `A..Z` (then `AA..`) across the top.

| Command | Does |
| --- | --- |
| `<row> <col>` or `reveal <row> <col>` | open a cell (`r`, `open` are aliases) |
| `flag <row> <col>` | place or remove a flag (`f`, `mark`) |
| `chord <row> <col>` | open the neighbours of a number once its flags match (`c`) |
| `go <row> <col>` | move the cursor without opening anything (`goto`) |
| `difficulty <name>` | switch preset, by name or `1`/`2`/`3` |
| `new` | restart at the current difficulty |
| `help` / `?` | list the commands |
| `quit` / `q` | leave |

In `--keys` mode: arrows move, `Enter`/`Space` reveals, `F` flags, `C` chords, `1`/`2`/`3` change
difficulty, `N` starts a new board, `Q` or `Esc` quits.

Colours are on when writing to a terminal and off when the output is redirected; set `NO_COLOR`
to force them off. The process exits `0` after a win, `1` otherwise.

## Rules

- The first click is always safe. On boards with room, the eight cells around it are safe too.
- Opening a cell with no adjacent mines cascades outward until it hits numbers.
- Chording a number whose surrounding flag count matches opens the rest of its neighbours — so a
  mistaken flag costs you the game.
- You win by opening every cell that is not a mine; remaining mines are flagged for you.

## Layout

```
src/Minesweeper.Core   rules and board state, no console calls
src/Minesweeper.Cli    command parsing, ANSI rendering, the game loop
tests/                 xUnit tests for the engine, parser, session, and renderer
```

```bash
dotnet build   # compiles all three projects
dotnet test    # runs the suite
```