1 files changed, 188 insertions, 0 deletions
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..3d77877
--- /dev/null
+++ b/main.go
@@ -0,0 +1,188 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	tea "github.com/charmbracelet/bubbletea"
+	"math/rand"
+	"os"
+	"time"
+)
+
+type point struct {
+	x, y int
+}
+
+type direction int
+
+const (
+	up = iota
+	right
+	down
+	left
+)
+
+func (d direction) toByte() byte {
+	return []byte{'^', '>', 'v', '<'}[d]
+}
+
+type tickMsg time.Time
+
+type model struct {
+	dx, dy      int
+	head        point
+	tail        []point
+	maxLen      int
+	dir, newDir direction
+	food        point
+	points      int
+}
+
+func (m model) toOffset(p point) int {
+	return p.y*(m.dx+1) + p.x
+}
+
+func (m model) isEmpty(p point) bool {
+	// Check collision with head
+	if p == m.head {
+		return false
+	}
+
+	// Check collision with borders
+	if p.x < 0 || p.x >= m.dx || p.y < 0 || p.y >= m.dy {
+		return false
+	}
+
+	// Check collision with tail
+	for _, t := range m.tail {
+		if p == t {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (m model) randFood() point {
+	candidate := point{x: rand.Intn(m.dx), y: rand.Intn(m.dy)}
+	for !m.isEmpty(candidate) {
+		candidate = point{x: rand.Intn(m.dx), y: rand.Intn(m.dy)}
+	}
+	return candidate
+}
+
+func initialModel() model {
+	m := model{
+		dx:     20,
+		dy:     10,
+		head:   point{1, 1},
+		tail:   make([]point, 0, 10),
+		maxLen: 5,
+		dir:    right,
+		newDir: right,
+		points: 0,
+	}
+	m.food = m.randFood()
+	return m
+}
+
+func tickCmd(points int) func() tea.Msg {
+	base := 300
+	scaled := base - (10 * points)
+	return tea.Tick(time.Millisecond*time.Duration(scaled), func(t time.Time) tea.Msg {
+		return tickMsg(t)
+	})
+}
+
+func (m model) Init() tea.Cmd {
+	return tickCmd(m.points)
+}
+
+func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		var newDir direction
+		switch msg.String() {
+		case "ctrl+c":
+			return m, tea.Quit
+		case "up", "k":
+			newDir = up
+		case "right", "l":
+			newDir = right
+		case "down", "j":
+			newDir = down
+		case "left", "h":
+			newDir = left
+		}
+
+		// Prevent from going in the reverse direction
+		if (newDir+2)%4 != m.dir {
+			m.newDir = newDir
+		}
+
+	case tickMsg:
+		// Calculate new head position
+		var newHead point
+		switch m.newDir {
+		case up:
+			newHead = point{m.head.x, m.head.y - 1}
+		case right:
+			newHead = point{m.head.x + 1, m.head.y}
+		case down:
+			newHead = point{m.head.x, m.head.y + 1}
+		case left:
+			newHead = point{m.head.x - 1, m.head.y}
+		}
+		m.dir = m.newDir
+
+		if !m.isEmpty(newHead) {
+			fmt.Println("DEP, siempre saludaba.")
+			return m, tea.Quit
+		}
+
+		// Good to go; update head and tail
+		m.tail = append(m.tail, m.head)
+		if len(m.tail) >= m.maxLen {
+			m.tail = m.tail[1:]
+		}
+		m.head = newHead
+
+		// Finally, when the snake eats the food:
+		if m.head == m.food {
+			m.food = m.randFood()
+			m.maxLen += 1
+			m.points += 1
+		}
+
+		return m, tickCmd(m.points)
+	}
+	return m, nil
+}
+
+func (m model) View() string {
+	// Generate board
+	row := append(bytes.Repeat([]byte{'-'}, m.dx), '\n')
+	board := bytes.Repeat(row, m.dy)
+
+	// Draw head
+	board[m.toOffset(m.head)] = m.dir.toByte()
+
+	// Draw tail
+	for _, p := range m.tail {
+		board[m.toOffset(p)] = '#'
+	}
+
+	// Draw food
+	board[m.toOffset(m.food)] = 'o'
+
+	return fmt.Sprintf("%s\nPoints: %d\n", string(board), m.points)
+}
+
+func main() {
+	rand.Seed(time.Now().UnixNano())
+	p := tea.NewProgram(initialModel())
+	if err := p.Start(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}