package settings

import (
	"os"
	"path/filepath"
	"testing"
)

func TestSaveLoadRoundTrip(t *testing.T) {
	path := filepath.Join(t.TempDir(), "settings.json")
	want := Settings{AIBackend: "codex", MarvinCmd: "uv run am", KnowledgePath: "/tmp/k.md"}
	if err := Save(path, want); err != nil {
		t.Fatalf("save: %v", err)
	}
	got, err := Load(path)
	if err != nil {
		t.Fatalf("load: %v", err)
	}
	if got != want {
		t.Errorf("round trip = %+v, want %+v", got, want)
	}
}

func TestLoadMissingFileIsError(t *testing.T) {
	_, err := Load(filepath.Join(t.TempDir(), "nope.json"))
	if err == nil {
		t.Fatal("want error loading missing file, got nil")
	}
}

func TestSeedFromEnvReadsVars(t *testing.T) {
	t.Setenv("ANTIDRIFT_AI_BACKEND", "codex")
	t.Setenv("ANTIDRIFT_MARVIN_CMD", "uv run am")
	t.Setenv("ANTIDRIFT_KNOWLEDGE_FILE", "/tmp/k.md")
	got := SeedFromEnv()
	want := Settings{AIBackend: "codex", MarvinCmd: "uv run am", KnowledgePath: "/tmp/k.md"}
	if got != want {
		t.Errorf("SeedFromEnv = %+v, want %+v", got, want)
	}
}

func TestSeedFromEnvDefaultsBackend(t *testing.T) {
	t.Setenv("ANTIDRIFT_AI_BACKEND", "")
	t.Setenv("ANTIDRIFT_MARVIN_CMD", "")
	t.Setenv("ANTIDRIFT_KNOWLEDGE_FILE", "")
	got := SeedFromEnv()
	if got.AIBackend != "claude" {
		t.Errorf("default backend = %q, want claude", got.AIBackend)
	}
}

func TestSaveCreatesDir(t *testing.T) {
	path := filepath.Join(t.TempDir(), "sub", "settings.json")
	if err := Save(path, Settings{AIBackend: "claude"}); err != nil {
		t.Fatalf("save: %v", err)
	}
	if _, err := os.Stat(path); err != nil {
		t.Fatalf("file not written: %v", err)
	}
}