1 files changed, 76 insertions, 0 deletions
diff --git a/internal/aitool/dispatch.go b/internal/aitool/dispatch.go
new file mode 100644
index 0000000..0924c8b
--- /dev/null
+++ b/internal/aitool/dispatch.go
@@ -0,0 +1,76 @@
+package aitool
+
+import "os/exec"
+
+type Tool string
+
+const (
+	ToolOpencode Tool = "opencode"
+	ToolHexAI    Tool = "hexai"
+	ToolClaude   Tool = "claude"
+	ToolAmp      Tool = "amp"
+)
+
+type LookPathFunc func(file string) (string, error)
+
+func Chain(preferred string) []Tool {
+	switch preferred {
+	case "", string(ToolOpencode):
+		return []Tool{ToolOpencode, ToolHexAI, ToolClaude, ToolAmp}
+	case string(ToolHexAI):
+		return []Tool{ToolHexAI, ToolClaude, ToolAmp}
+	case string(ToolClaude), "claude-code":
+		return []Tool{ToolClaude, ToolAmp}
+	case string(ToolAmp):
+		return []Tool{ToolAmp}
+	default:
+		return nil
+	}
+}
+
+func FirstAvailable(preferred string, lookPath LookPathFunc) Tool {
+	for _, tool := range Chain(preferred) {
+		if IsAvailable(tool, lookPath) {
+			return tool
+		}
+	}
+
+	return ""
+}
+
+func AvailableChain(preferred string, lookPath LookPathFunc) []Tool {
+	chain := Chain(preferred)
+	available := make([]Tool, 0, len(chain))
+	for _, tool := range chain {
+		if IsAvailable(tool, lookPath) {
+			available = append(available, tool)
+		}
+	}
+
+	return available
+}
+
+func IsAvailable(tool Tool, lookPath LookPathFunc) bool {
+	if lookPath == nil {
+		lookPath = exec.LookPath
+	}
+
+	binary, ok := availabilityBinary(tool)
+	if !ok {
+		return false
+	}
+
+	_, err := lookPath(binary)
+	return err == nil
+}
+
+func availabilityBinary(tool Tool) (string, bool) {
+	switch tool {
+	case ToolOpencode:
+		return "ollama", true
+	case ToolHexAI, ToolClaude, ToolAmp:
+		return string(tool), true
+	default:
+		return "", false
+	}
+}