feat: extension system

internal/shell/extensions/dotnet.go

@@ -0,0 +1,25 @@
+package extensions
+
+import (
+	"os"
+	"smash/internal/color"
+	"strings"
+)
+
+type dotnet struct {
+}
+
+const dotnetPromptDisplay = color.FgMagenta + "\U000F0AAE"
+
+func (_ *dotnet) PromptDisplay() string {
+	return dotnetPromptDisplay
+}
+
+func (_ *dotnet) FileMatch(f os.DirEntry, _ string) bool {
+	n := f.Name()
+	return strings.HasSuffix(n, ".sln") || strings.HasSuffix(n, ".csproj") || strings.HasSuffix(n, ".fsproj")
+}
+
+func init() {
+	register(&dotnet{})
+}

internal/shell/extensions/extensions.go

@@ -0,0 +1,74 @@
+package extensions
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+var extensionRegister []*extensionWrapper
+
+type (
+	Extension interface {
+		PromptDisplay() string
+		FileMatch(f os.DirEntry, p string) bool
+	}
+	extensionWrapper struct {
+		extension Extension
+		active    bool
+	}
+)
+
+func register(e Extension) {
+	extensionRegister = append(extensionRegister, &extensionWrapper{extension: e, active: true})
+}
+
+func priorityRegister(e Extension) {
+	extensionRegister = append([]*extensionWrapper{{extension: e, active: true}}, extensionRegister...)
+}
+
+func SetContext(root string) error {
+	// deactivate all extensions
+	for _, ew := range extensionRegister {
+		ew.active = false
+	}
+
+	// activate extensions that match the current context
+	for {
+		entries, err := os.ReadDir(root)
+		if err != nil {
+			return errors.Join(errors.New("failed to read directory"), err)
+		}
+		for _, f := range entries {
+			p := filepath.Join(root, f.Name())
+			for _, ew := range extensionRegister {
+				if ew.active {
+					continue
+				}
+				if ew.extension.FileMatch(f, p) {
+					ew.active = true
+					continue
+				}
+			}
+		}
+
+		nextRoot := filepath.Dir(root)
+		if nextRoot == root {
+			break
+		}
+		root = nextRoot
+	}
+	return nil
+}
+
+func PromptDisplay() string {
+	sb := strings.Builder{}
+	for _, ew := range extensionRegister {
+		if ew.active {
+			sb.WriteString(ew.extension.PromptDisplay())
+			sb.WriteString(" ")
+		}
+	}
+	return sb.String()
+}

internal/shell/extensions/git.go

@@ -0,0 +1,28 @@
+package extensions
+
+import (
+	"os"
+	"os/exec"
+	"smash/internal/color"
+	"strings"
+)
+
+type git struct {
+}
+
+func (_ *git) PromptDisplay() string {
+	cmd := exec.Command("git", "branch", "--show-current")
+	if out, err := cmd.Output(); err == nil {
+		return color.FgGreen + "\U000F02A2 " + strings.TrimSpace(string(out))
+	} else {
+		return color.FgGreen + "\U000F02A2"
+	}
+}
+
+func (_ *git) FileMatch(f os.DirEntry, _ string) bool {
+	return f.Name() == ".git"
+}
+
+func init() {
+	priorityRegister(&git{})
+}

internal/shell/extensions/golang.go

@@ -0,0 +1,45 @@
+package extensions
+
+import (
+	"bufio"
+	"os"
+	"smash/internal/color"
+	"strings"
+)
+
+type golang struct {
+	mod string
+}
+
+const goPromptDisplay = color.FgBlue + "\uE627"
+
+func (g *golang) PromptDisplay() string {
+	f, err := os.Open(g.mod)
+	if err != nil {
+		return goPromptDisplay
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	scanner.Split(bufio.ScanLines)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "go ") {
+			return goPromptDisplay + " " + strings.TrimSpace(line[3:])
+		}
+	}
+	return goPromptDisplay
+}
+
+func (g *golang) FileMatch(f os.DirEntry, p string) bool {
+	if f.Name() == "go.mod" {
+		g.mod = p
+		return true
+	}
+	return false
+}
+
+func init() {
+	register(&golang{})
+}

internal/shell/extensions/ruby.go

@@ -0,0 +1,46 @@
+package extensions
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"smash/internal/color"
+)
+
+type ruby struct {
+	gemfile string
+}
+
+const rubyPromptDisplay = color.FgRed + "\uE739"
+
+func (ru *ruby) PromptDisplay() string {
+	f, err := os.Open(ru.gemfile)
+	if err != nil {
+		return rubyPromptDisplay
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	scanner.Split(bufio.ScanLines)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		var version string
+		if _, err := fmt.Sscanf(line, `ruby "%s"`, &version); err == nil {
+			return rubyPromptDisplay + " " + version
+		}
+	}
+	return rubyPromptDisplay
+}
+
+func (ru *ruby) FileMatch(f os.DirEntry, p string) bool {
+	if f.Name() == "Gemfile" {
+		ru.gemfile = p
+		return true
+	}
+	return false
+}
+
+func init() {
+	register(&ruby{})
+}