// Package config tests verify configuration loading from
// environment variables and .env files.
package config

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

func TestLoad_WithValidEnv(t *testing.T) {
	t.Setenv("KAOS_TIMEOUT", "30m")
	t.Setenv("KAOS_PROJECT_PATH", "/tmp/test")
	t.Setenv("KAOS_TASKS_DIR", "/tmp/tasks")

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

	if cfg.Timeout != 30*time.Minute {
		t.Errorf("expected timeout 30m, got %v", cfg.Timeout)
	}

	if cfg.ProjectPath != "/tmp/test" {
		t.Errorf("expected project path /tmp/test, got %s", cfg.ProjectPath)
	}

	if cfg.TasksDir != "/tmp/tasks" {
		t.Errorf("expected tasks dir /tmp/tasks, got %s", cfg.TasksDir)
	}
}

func TestLoad_MissingTimeout(t *testing.T) {
	t.Setenv("KAOS_TIMEOUT", "")
	t.Setenv("KAOS_PROJECT_PATH", "/tmp/test")
	t.Setenv("KAOS_TASKS_DIR", "/tmp/tasks")

	_, err := Load()
	if err == nil {
		t.Fatal("expected error for missing KAOS_TIMEOUT")
	}
}

func TestLoad_InvalidTimeout(t *testing.T) {
	t.Setenv("KAOS_TIMEOUT", "not-a-duration")
	t.Setenv("KAOS_PROJECT_PATH", "/tmp/test")
	t.Setenv("KAOS_TASKS_DIR", "/tmp/tasks")

	_, err := Load()
	if err == nil {
		t.Fatal("expected error for invalid KAOS_TIMEOUT")
	}
}

func TestLoad_MissingProjectPath(t *testing.T) {
	t.Setenv("KAOS_TIMEOUT", "30m")
	t.Setenv("KAOS_PROJECT_PATH", "")
	t.Setenv("KAOS_TASKS_DIR", "/tmp/tasks")

	_, err := Load()
	if err == nil {
		t.Fatal("expected error for missing KAOS_PROJECT_PATH")
	}
}

func TestLoad_MissingTasksDir(t *testing.T) {
	t.Setenv("KAOS_TIMEOUT", "30m")
	t.Setenv("KAOS_PROJECT_PATH", "/tmp/test")
	t.Setenv("KAOS_TASKS_DIR", "")

	_, err := Load()
	if err == nil {
		t.Fatal("expected error for missing KAOS_TASKS_DIR")
	}
}

func TestLoadEnvFile(t *testing.T) {
	dir := t.TempDir()
	envPath := filepath.Join(dir, ".env")

	content := "TEST_KAOS_VAR=hello\n# comment\nTEST_KAOS_OTHER=world\n"
	if err := os.WriteFile(envPath, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write .env: %v", err)
	}

	// Ensure vars are not set
	os.Unsetenv("TEST_KAOS_VAR")
	os.Unsetenv("TEST_KAOS_OTHER")

	loadEnvFile(envPath)

	if v := os.Getenv("TEST_KAOS_VAR"); v != "hello" {
		t.Errorf("expected TEST_KAOS_VAR=hello, got %q", v)
	}
	if v := os.Getenv("TEST_KAOS_OTHER"); v != "world" {
		t.Errorf("expected TEST_KAOS_OTHER=world, got %q", v)
	}

	// Cleanup
	os.Unsetenv("TEST_KAOS_VAR")
	os.Unsetenv("TEST_KAOS_OTHER")
}

func TestLoadEnvFile_DoesNotOverride(t *testing.T) {
	dir := t.TempDir()
	envPath := filepath.Join(dir, ".env")

	content := "TEST_KAOS_EXISTING=from_file\n"
	if err := os.WriteFile(envPath, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write .env: %v", err)
	}

	t.Setenv("TEST_KAOS_EXISTING", "from_env")

	loadEnvFile(envPath)

	if v := os.Getenv("TEST_KAOS_EXISTING"); v != "from_env" {
		t.Errorf("expected TEST_KAOS_EXISTING=from_env, got %q", v)
	}
}