refactor: massive refactor to have only one binary to call

2020/day01/go.mod

@@ -1,3 +0,0 @@
-module 2020/day01
-
-go 1.25.4

2020/day02/go.mod

@@ -1,3 +0,0 @@
-module 2020/day02
-
-go 1.25.4

2020/day03/go.mod

@@ -1,3 +0,0 @@
-module 2020/day03
-
-go 1.25.4

2020/day04/go.mod

@@ -1,3 +0,0 @@
-module 2020/day04
-
-go 1.25.4

2020/day05/go.mod

@@ -1,3 +0,0 @@
-module 2020/day05
-
-go 1.25.4

2020/day06/go.mod

@@ -1,3 +0,0 @@
-module 2020/day06
-
-go 1.25.4

2021/day01/go.mod

@@ -1,3 +0,0 @@
-module 2021/day01
-
-go 1.25.4

2021/day02/go.mod

@@ -1,3 +0,0 @@
-module 2021/day02
-
-go 1.25.4

2021/day03/go.mod

@@ -1,3 +0,0 @@
-module 2021/day03
-
-go 1.25.4

Makefile

@@ -0,0 +1,13 @@
+GO = go
+BIN = bin/aoc
+
+.PHONY: build test clean
+
+build:
+	$(GO) build -o $(BIN) ./cmd/aoc
+
+test:
+	$(GO) test ./...
+
+clean:
+	rm -f $(BIN)

README.md

@@ -16,26 +16,61 @@ Also, it's a fresh start from 2025. I do some exercises from other years along t
 ## Repository Structure
 
 ```
-yyyy/
-├── dayXX/
-│   ├── main.go      # The main code to run to print solutions.
-│   ├── main_test.go # The test file that validates the logic.
-│   └── input.txt    # The day's puzzle input.
+├── cmd/
+│   └── aoc/
+│       └── main.go                # CLI entry point that runs solutions
+└── internal/
+    ├── 2020/
+    │   ├── DayOne/
+    │   │   ├── code.go            # Go solution for Day 1 (2020)
+    │   │   └── code_test.go       # Unit tests for Day 1
+    │   └── ...
+    ├── 2021/
+    │   └── ...                    # Additional years and days
+    ├── registry/
+    │   └── registry.go            # Central registry for day runners
+    └── data/
+        ├── 2020/
+        │   ├── DayOne/
+        │   │   └── input.txt      # Puzzle input for Day 1 (2020)
+        │   └── ...
         └── ...
 ```
 
-Each day's code can be run with:
+Each day's solution is organized into its own folder, named according to the day number (e.g., `DayOne`, `DayTwo`). Inside each folder, you'll find a `code.go` file with the Go implementation of the solution and a `code_test.go` file containing corresponding tests. The input data for each puzzle is located in the `internal/data` directory, mirroring the code structure for easy access.
+
+To connect each solution to the CLI, the repository uses a central registry located in `internal/registry/registry.go`. This registry is essentially a map linking a day key (combining year and day number) to assign a "day runner" which is a struct that specifies the `ParseInput`, `PartOne` and `PartTwo` functions of the day's problem.
+
+When running a solution, the CLI (`cmd/aoc/main.go`) looks up the appropriate runner from the registry based on your command-line input, uses the parsing function to load the input data, and then runs the desired part (or both parts) using the registered solution functions.
+
+## Usage
+
+Build the CLI tool:
 
 ```bash
-cd yyyy/dayXX
-go run main.go
+make
 ```
 
-Expected output:
+Run a day's solution:
 
 ```bash
-Part 1: <answer>
-Part 2: <answer>
+bin/aoc 2020D1      # Run both parts
+bin/aoc 2020D1P1    # Run only part one
+bin/aoc 2020D1P2    # Run only part two
+```
+
+Example output:
+
+```bash
+$ bin/aoc 2020D1
+197451
+138233720
+
+$ bin/aoc 2020D1P1
+197451
+
+$ bin/aoc 2020D1P2
+138233720
 ```
 
 ## Tests
@@ -55,13 +90,18 @@ In this example, the calibration values of these four lines are 12, 38, 15, and
 Adding these together produces 142.
 ```
 
-I'm using these examples to validate my logic.
+I'm using these examples each day to validate my logic.
 
-If you want to run those, you can use:
+Run all tests:
 
 ```bash
-cd dayXX
-go test
+make test
+```
+
+Or run tests for a specific day:
+
+```bash
+go test ./internal/2020/DayOne/...
 ```
 
 ## Notes

cmd/aoc/main.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"advent-of-code/internal/registry"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+
+	_ "advent-of-code/internal/2020/DayFour"
+	_ "advent-of-code/internal/2020/DayOne"
+	_ "advent-of-code/internal/2020/DaySix"
+	_ "advent-of-code/internal/2020/DayThree"
+	_ "advent-of-code/internal/2020/DayTwo"
+	_ "advent-of-code/internal/2021/DayOne"
+	_ "advent-of-code/internal/2021/DayThree"
+	_ "advent-of-code/internal/2021/DayTwo"
+)
+
+func capitalize(day string) string {
+	dayNames := map[string]string{
+		"1": "One", "2": "Two", "3": "Three", "4": "Four", "5": "Five",
+		"6": "Six", "7": "Seven", "8": "Eight", "9": "Nine", "10": "Ten",
+		"11": "Eleven", "12": "Twelve", "13": "Thirteen", "14": "Fourteen", "15": "Fifteen",
+		"16": "Sixteen", "17": "Seventeen", "18": "Eighteen", "19": "Nineteen", "20": "Twenty",
+		"21": "TwentyOne", "22": "TwentyTwo", "23": "TwentyThree", "24": "TwentyFour", "25": "TwentyFive",
+	}
+	return dayNames[day]
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintf(os.Stderr, "Usage: %s <YEAR>D<DAY>[P<PART>]\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	re := regexp.MustCompile(`^(\d{4})D(\d+)(?:P(\d+))?$`)
+	matches := re.FindStringSubmatch(os.Args[1])
+	if matches == nil {
+		fmt.Fprintf(os.Stderr, "Invalid format: %s\n", os.Args[1])
+		os.Exit(1)
+	}
+
+	year, dayNum, part := matches[1], matches[2], matches[3]
+	dayKey := fmt.Sprintf("%sD%s", year, dayNum)
+	dayName := fmt.Sprintf("Day%s", capitalize(dayNum))
+	input := filepath.Join("internal", "data", year, dayName, "input.txt")
+
+	runner, ok := registry.Days[dayKey].(registry.Runner)
+	if !ok {
+		log.Fatalf("Day not found: %s\n", dayKey)
+	}
+
+	runner.Run(input, part)
+}

go.mod

@@ -0,0 +1,3 @@
+module advent-of-code
+
+go 1.25.4

internal/2020/DayFive/code.go

@@ -1,18 +1,13 @@
-package main
+package dayfive
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strings"
 )
 
-func parseInput(file string) []string {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
-	}
-	return strings.Split(string(content), "\n")
+func init() {
+	registry.Register("2020D5", ParseInput, PartOne, PartTwo)
 }
 
 func calculateSeatID(pass string) int {
@@ -39,6 +34,11 @@ func calculateSeatID(pass string) int {
 	return row*8 + column
 }
 
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
+	return strings.Split(string(content), "\n")
+}
+
 func PartOne(input []string) int {
 	maxSeatID := 0
 	for _, pass := range input {
@@ -77,9 +77,3 @@ func PartTwo(input []string) int {
 
 	return 0
 }
-
-func main() {
-	input := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(input))
-	fmt.Println("Part 2:", PartTwo(input))
-}

internal/2020/DayFive/code_test.go

@@ -1,4 +1,4 @@
-package main
+package dayfive
 
 import "testing"
 
@@ -32,3 +32,4 @@ func TestPartTwo(t *testing.T) {
 		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2020/DayFour/code.go

@@ -1,19 +1,19 @@
-package main
+package dayfour
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strconv"
 	"strings"
 )
 
-func parseInput(file string) []string {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2020D4", ParseInput, PartOne, PartTwo)
 }
 
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
+
 	text := string(content)
 	passports := strings.Split(text, "\n\n")
 
@@ -152,8 +152,3 @@ func PartTwo(data []string) int {
 	return count
 }
 
-func main() {
-	data := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(data))
-	fmt.Println("Part 2:", PartTwo(data))
-}

internal/2020/DayFour/code_test.go

@@ -1,4 +1,4 @@
-package main
+package dayfour
 
 import "testing"
 
@@ -13,7 +13,7 @@ func TestPartOne(t *testing.T) {
 	expected := 2
 	got := PartOne(testInput)
 	if got != expected {
-		t.Errorf("PartOne(%v) = %d, want %d", testInput, got, expected)
+		t.Errorf("PartOne() = %d, want %d", got, expected)
 	}
 }
 
@@ -21,6 +21,7 @@ func TestPartTwo(t *testing.T) {
 	expected := 2
 	got := PartTwo(testInput)
 	if got != expected {
-		t.Errorf("PartTwo(%v) = %d, want %d", testInput, got, expected)
+		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2020/DayOne/code.go

@@ -1,25 +1,22 @@
-package main
+package dayone
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strconv"
 	"strings"
 )
 
-func parseInput(file string) []int {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2020D1", ParseInput, PartOne, PartTwo)
 }
+
+func ParseInput(filepath string) []int {
+	content, _ := os.ReadFile(filepath)
 	lines := strings.Fields(string(content))
 	var data []int
 	for _, line := range lines {
-		num, err := strconv.Atoi(line)
-		if err != nil {
-			log.Fatalf("Failed to convert string to int: %v", err)
-		}
+		num, _ := strconv.Atoi(line)
 		data = append(data, num)
 	}
 	return data
@@ -51,8 +48,3 @@ func PartTwo(data []int) int {
 	return 0
 }
 
-func main() {
-	data := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(data))
-	fmt.Println("Part 2:", PartTwo(data))
-}

internal/2020/DayOne/code_test.go

@@ -1,4 +1,4 @@
-package main
+package dayone
 
 import "testing"
 
@@ -8,7 +8,7 @@ func TestPartOne(t *testing.T) {
 	expected := 514579
 	got := PartOne(testInput)
 	if got != expected {
-		t.Errorf("PartOne(%v) = %d, want %d", testInput, got, expected)
+		t.Errorf("PartOne() = %d, want %d", got, expected)
 	}
 }
 
@@ -16,6 +16,7 @@ func TestPartTwo(t *testing.T) {
 	expected := 241861950
 	got := PartTwo(testInput)
 	if got != expected {
-		t.Errorf("PartTwo(%v) = %d, want %d", testInput, got, expected)
+		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2020/DaySix/code.go

@@ -1,17 +1,17 @@
-package main
+package daysix
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strings"
 )
 
-func parseInput(file string) []string {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2020D6", ParseInput, PartOne, PartTwo)
 }
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
 	return strings.Split(strings.TrimSpace(string(content)), "\n")
 }
 
@@ -68,8 +68,3 @@ func PartTwo(input []string) int {
 	return total
 }
 
-func main() {
-	input := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(input))
-	fmt.Println("Part 2:", PartTwo(input))
-}

internal/2020/DaySix/code_test.go

@@ -1,8 +1,8 @@
-package main
+package daysix
 
 import "testing"
 
-var input = []string{
+var testInput = []string{
 	"abc",
 	"",
 	"a",
@@ -22,7 +22,7 @@ var input = []string{
 
 func TestPartOne(t *testing.T) {
 	expected := 11
-	got := PartOne(input)
+	got := PartOne(testInput)
 	if got != expected {
 		t.Errorf("PartOne() = %d, want %d", got, expected)
 	}
@@ -30,8 +30,9 @@ func TestPartOne(t *testing.T) {
 
 func TestPartTwo(t *testing.T) {
 	expected := 6
-	got := PartTwo(input)
+	got := PartTwo(testInput)
 	if got != expected {
 		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2020/DayThree/code.go

@@ -1,17 +1,17 @@
-package main
+package daythree
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strings"
 )
 
-func parseInput(file string) []string {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2020D3", ParseInput, PartOne, PartTwo)
 }
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
 	return strings.Split(string(content), "\n")
 }
 
@@ -50,8 +50,3 @@ func PartTwo(input []string) int {
 	return result
 }
 
-func main() {
-	data := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(data))
-	fmt.Println("Part 2:", PartTwo(data))
-}

internal/2020/DayThree/code_test.go

@@ -1,4 +1,4 @@
-package main
+package daythree
 
 import "testing"
 
@@ -31,3 +31,4 @@ func TestPartTwo(t *testing.T) {
 		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2020/DayTwo/code.go

@@ -1,18 +1,18 @@
-package main
+package daytwo
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strconv"
 	"strings"
 )
 
-func parseInput(file string) []string {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2020D2", ParseInput, PartOne, PartTwo)
 }
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
 	lines := strings.Split(string(content), "\n")
 	var data []string
 	for _, line := range lines {
@@ -75,8 +75,3 @@ func PartTwo(data []string) int {
 	return valid
 }
 
-func main() {
-	data := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(data))
-	fmt.Println("Part 2:", PartTwo(data))
-}

internal/2020/DayTwo/code_test.go

@@ -1,4 +1,4 @@
-package main
+package daytwo
 
 import "testing"
 
@@ -12,7 +12,7 @@ func TestPartOne(t *testing.T) {
 	expected := 2
 	got := PartOne(testInput)
 	if got != expected {
-		t.Errorf("PartOne(%v) = %d, want %d", testInput, got, expected)
+		t.Errorf("PartOne() = %d, want %d", got, expected)
 	}
 }
 
@@ -20,6 +20,7 @@ func TestPartTwo(t *testing.T) {
 	expected := 1
 	got := PartTwo(testInput)
 	if got != expected {
-		t.Errorf("PartTwo(%v) = %d, want %d", testInput, got, expected)
+		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2021/DayOne/code.go

@@ -1,24 +1,21 @@
-package main
+package dayone
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strconv"
 	"strings"
 )
 
-func parseInput(file string) []int {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2021D1", ParseInput, PartOne, PartTwo)
 }
+
+func ParseInput(filepath string) []int {
+	content, _ := os.ReadFile(filepath)
 	var data []int
 	for line := range strings.SplitSeq(string(content), "\n") {
-		num, err := strconv.Atoi(line)
-		if err != nil {
-			log.Fatalf("Failed to convert string to int: %v", err)
-		}
+		num, _ := strconv.Atoi(line)
 		data = append(data, num)
 	}
 	return data
@@ -44,8 +41,3 @@ func PartTwo(data []int) int {
 	return count
 }
 
-func main() {
-	data := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(data))
-	fmt.Println("Part 2:", PartTwo(data))
-}

internal/2021/DayOne/code_test.go

@@ -1,4 +1,4 @@
-package main
+package dayone
 
 import "testing"
 
@@ -19,3 +19,4 @@ func TestPartTwo(t *testing.T) {
 		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2021/DayThree/code.go

@@ -1,17 +1,17 @@
-package main
+package daythree
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strings"
 )
 
-func parseInput(file string) []string {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2021D3", ParseInput, PartOne, PartTwo)
 }
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
 	return strings.Split(strings.TrimSpace(string(content)), "\n")
 }
 
@@ -115,8 +115,3 @@ func PartTwo(data []string) int {
 	return oxygenRating * co2Rating
 }
 
-func main() {
-	data := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(data))
-	fmt.Println("Part 2:", PartTwo(data))
-}

internal/2021/DayThree/code_test.go

@@ -1,4 +1,4 @@
-package main
+package daythree
 
 import "testing"
 
@@ -32,3 +32,4 @@ func TestPartTwo(t *testing.T) {
 		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/2021/DayTwo/code.go

@@ -1,18 +1,18 @@
-package main
+package daytwo
 
 import (
-	"fmt"
-	"log"
+	"advent-of-code/internal/registry"
 	"os"
 	"strconv"
 	"strings"
 )
 
-func parseInput(file string) []string {
-	content, err := os.ReadFile(file)
-	if err != nil {
-		log.Fatalf("Failed to read input file: %v", err)
+func init() {
+	registry.Register("2021D2", ParseInput, PartOne, PartTwo)
 }
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
 	return strings.Split(string(content), "\n")
 }
 
@@ -58,8 +58,3 @@ func PartTwo(data []string) int {
 	return horizontal * depth
 }
 
-func main() {
-	data := parseInput("input.txt")
-	fmt.Println("Part 1:", PartOne(data))
-	fmt.Println("Part 2:", PartTwo(data))
-}

internal/2021/DayTwo/code_test.go

@@ -1,4 +1,4 @@
-package main
+package daytwo
 
 import "testing"
 
@@ -26,3 +26,4 @@ func TestPartTwo(t *testing.T) {
 		t.Errorf("PartTwo() = %d, want %d", got, expected)
 	}
 }
+

internal/registry/registry.go

@@ -0,0 +1,42 @@
+package registry
+
+import (
+	"fmt"
+	"os"
+)
+
+type Runner interface {
+	Run(input string, part string)
+}
+
+type DayRunner[T any] struct {
+	ParseInput func(string) T
+	PartOne    func(T) int
+	PartTwo    func(T) int
+}
+
+func (r *DayRunner[T]) Run(input string, part string) {
+	data := r.ParseInput(input)
+	switch part {
+	case "":
+		fmt.Println(r.PartOne(data))
+		fmt.Println(r.PartTwo(data))
+	case "1":
+		fmt.Println(r.PartOne(data))
+	case "2":
+		fmt.Println(r.PartTwo(data))
+	default:
+		fmt.Fprintf(os.Stderr, "Invalid part: %s\n", part)
+		os.Exit(1)
+	}
+}
+
+var Days = make(map[string]any)
+
+func Register[T any](key string, parseInput func(string) T, partOne func(T) int, partTwo func(T) int) {
+	Days[key] = &DayRunner[T]{
+		ParseInput: parseInput,
+		PartOne:    partOne,
+		PartTwo:    partTwo,
+	}
+}