package config

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

func TestLoadUsesRootsFromEnvironment(t *testing.T) {
	t.Setenv(rootsEnvVar, `[{"name":"Media","path":"/mnt/media"},{"name":"Archive","path":"/mnt/archive"}]`)
	t.Setenv(rootsFileEnvVar, "")

	config, err := Load()
	if err != nil {
		t.Fatalf("Load() error = %v", err)
	}

	want := []Root{
		{Name: "Media", Path: "/mnt/media"},
		{Name: "Archive", Path: "/mnt/archive"},
	}
	if !reflect.DeepEqual(config.Roots, want) {
		t.Errorf("Load().Roots = %#v, want %#v", config.Roots, want)
	}
}

func TestLoadUsesRootsFromFile(t *testing.T) {
	configPath := filepath.Join(t.TempDir(), "roots.json")
	contents := `{
  "roots": [
    {"name": "Documents", "path": "/mnt/documents"}
  ]
}`
	if err := os.WriteFile(configPath, []byte(contents), 0o600); err != nil {
		t.Fatal(err)
	}

	t.Setenv(rootsEnvVar, "")
	t.Setenv(rootsFileEnvVar, configPath)

	config, err := Load()
	if err != nil {
		t.Fatalf("Load() error = %v", err)
	}

	want := []Root{{Name: "Documents", Path: "/mnt/documents"}}
	if !reflect.DeepEqual(config.Roots, want) {
		t.Errorf("Load().Roots = %#v, want %#v", config.Roots, want)
	}
}

func TestLoadEnvironmentOverridesRootsFile(t *testing.T) {
	configPath := filepath.Join(t.TempDir(), "roots.json")
	if err := os.WriteFile(configPath, []byte(`{"roots":[{"name":"File root","path":"/mnt/from-file"}]}`), 0o600); err != nil {
		t.Fatal(err)
	}

	t.Setenv(rootsFileEnvVar, configPath)
	t.Setenv(rootsEnvVar, `[{"name":"Environment root","path":"/mnt/from-environment"}]`)

	config, err := Load()
	if err != nil {
		t.Fatalf("Load() error = %v", err)
	}

	want := []Root{{Name: "Environment root", Path: "/mnt/from-environment"}}
	if !reflect.DeepEqual(config.Roots, want) {
		t.Errorf("Load().Roots = %#v, want %#v", config.Roots, want)
	}
}

func TestLoadRejectsInvalidRoots(t *testing.T) {
	t.Setenv(rootsFileEnvVar, "")

	tests := []struct {
		name  string
		value string
	}{
		{name: "empty list", value: `[]`},
		{name: "relative path", value: `[{"name":"Media","path":"relative/path"}]`},
		{name: "blank name", value: `[{"name":" ","path":"/mnt/media"}]`},
		{name: "duplicate names", value: `[{"name":"Media","path":"/mnt/media"},{"name":"Media","path":"/mnt/archive"}]`},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			t.Setenv(rootsEnvVar, test.value)

			if _, err := Load(); err == nil {
				t.Fatal("Load() error = nil, want an error")
			}
		})
	}
}