package config

import (
	"os"
	"testing"
)

func TestLoad(t *testing.T) {
	// Clean up any existing env vars
	cleanup := cleanEnv()
	defer cleanup()

	// Set test values
	os.Setenv("TECHNITIUM_URL", "https://test.dns.example.com")
	os.Setenv("TECHNITIUM_TOKEN", "test-token-12345")
	os.Setenv("BASE_DOMAIN", "test.rip")
	os.Setenv("SPACE_SUBDOMAIN", "dyn")
	os.Setenv("RATE_LIMIT_PER_IP", "20")
	os.Setenv("RATE_LIMIT_PER_TOKEN", "5")

	cfg := Load()

	tests := []struct {
		name     string
		got      string
		expected string
	}{
		{"TechnitiumURL", cfg.TechnitiumURL, "https://test.dns.example.com"},
		{"TechnitiumToken", cfg.TechnitiumToken, "test-token-12345"},
		{"BaseDomain", cfg.BaseDomain, "test.rip"},
		{"SpaceSubdomain", cfg.SpaceSubdomain, "dyn"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.got != tt.expected {
				t.Errorf("%s = %v, want %v", tt.name, tt.got, tt.expected)
			}
		})
	}

	// Test numeric values
	if cfg.RateLimitPerIP != 20 {
		t.Errorf("RateLimitPerIP = %v, want 20", cfg.RateLimitPerIP)
	}

	if cfg.RateLimitPerToken != 5 {
		t.Errorf("RateLimitPerToken = %v, want 5", cfg.RateLimitPerToken)
	}
}

func TestLoadDefaults(t *testing.T) {
	cleanup := cleanEnv()
	defer cleanup()

	cfg := Load()

	tests := []struct {
		name     string
		got      string
		expected string
	}{
		{"ServerPort", cfg.ServerPort, "8080"},
		{"DatabasePath", cfg.DatabasePath, "./dyn.db"},
		{"BaseDomain", cfg.BaseDomain, "dws.rip"},
		{"SpaceSubdomain", cfg.SpaceSubdomain, "space"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.got != tt.expected {
				t.Errorf("%s = %v, want %v", tt.name, tt.got, tt.expected)
			}
		})
	}

	// Test default numeric values
	if cfg.RateLimitPerIP != 10 {
		t.Errorf("RateLimitPerIP default = %v, want 10", cfg.RateLimitPerIP)
	}

	if cfg.RateLimitPerToken != 1 {
		t.Errorf("RateLimitPerToken default = %v, want 1", cfg.RateLimitPerToken)
	}
}

func TestValidate(t *testing.T) {
	tests := []struct {
		name       string
		setupEnv   func()
		wantErrors int
	}{
		{
			name: "valid config with token",
			setupEnv: func() {
				os.Setenv("TECHNITIUM_URL", "https://dns.example.com")
				os.Setenv("TECHNITIUM_TOKEN", "valid-token")
			},
			wantErrors: 0,
		},
		{
			name: "valid config with username/password",
			setupEnv: func() {
				os.Setenv("TECHNITIUM_URL", "https://dns.example.com")
				os.Setenv("TECHNITIUM_USERNAME", "admin")
				os.Setenv("TECHNITIUM_PASSWORD", "secret")
				os.Unsetenv("TECHNITIUM_TOKEN")
			},
			wantErrors: 0,
		},
		{
			name: "missing url",
			setupEnv: func() {
				os.Unsetenv("TECHNITIUM_URL")
				os.Setenv("TECHNITIUM_TOKEN", "token")
			},
			wantErrors: 1,
		},
		{
			name: "missing auth",
			setupEnv: func() {
				os.Setenv("TECHNITIUM_URL", "https://dns.example.com")
				os.Unsetenv("TECHNITIUM_TOKEN")
				os.Unsetenv("TECHNITIUM_USERNAME")
				os.Unsetenv("TECHNITIUM_PASSWORD")
			},
			wantErrors: 1,
		},
		{
			name: "missing everything",
			setupEnv: func() {
				os.Unsetenv("TECHNITIUM_URL")
				os.Unsetenv("TECHNITIUM_TOKEN")
				os.Unsetenv("TECHNITIUM_USERNAME")
				os.Unsetenv("TECHNITIUM_PASSWORD")
			},
			wantErrors: 2,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			cleanup := cleanEnv()
			defer cleanup()

			tt.setupEnv()
			cfg := Load()
			errors := cfg.Validate()

			if len(errors) != tt.wantErrors {
				t.Errorf("Validate() returned %d errors, want %d: %v", len(errors), tt.wantErrors, errors)
			}
		})
	}
}

func TestGetZone(t *testing.T) {
	tests := []struct {
		name     string
		base     string
		space    string
		expected string
	}{
		{
			name:     "with space subdomain",
			base:     "dws.rip",
			space:    "space",
			expected: "space.dws.rip",
		},
		{
			name:     "without space subdomain",
			base:     "dws.rip",
			space:    "",
			expected: "dws.rip",
		},
		{
			name:     "nested subdomain",
			base:     "example.com",
			space:    "dyn.space",
			expected: "dyn.space.example.com",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			cfg := &Config{
				BaseDomain:     tt.base,
				SpaceSubdomain: tt.space,
			}

			got := cfg.GetZone()
			if got != tt.expected {
				t.Errorf("GetZone() = %v, want %v", got, tt.expected)
			}
		})
	}
}

func TestGetEnv(t *testing.T) {
	tests := []struct {
		name         string
		key          string
		value        string
		defaultValue string
		expected     string
	}{
		{
			name:         "env set",
			key:          "TEST_KEY",
			value:        "test-value",
			defaultValue: "default",
			expected:     "test-value",
		},
		{
			name:         "env not set",
			key:          "UNSET_TEST_KEY",
			value:        "",
			defaultValue: "default",
			expected:     "default",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.value != "" {
				os.Setenv(tt.key, tt.value)
				defer os.Unsetenv(tt.key)
			}

			got := getEnv(tt.key, tt.defaultValue)
			if got != tt.expected {
				t.Errorf("getEnv() = %v, want %v", got, tt.expected)
			}
		})
	}
}

func TestGetEnvAsInt(t *testing.T) {
	tests := []struct {
		name         string
		value        string
		defaultValue int
		expected     int
	}{
		{
			name:         "valid int",
			value:        "42",
			defaultValue: 10,
			expected:     42,
		},
		{
			name:         "invalid int",
			value:        "not-a-number",
			defaultValue: 10,
			expected:     10,
		},
		{
			name:         "empty value",
			value:        "",
			defaultValue: 10,
			expected:     10,
		},
		{
			name:         "negative int",
			value:        "-5",
			defaultValue: 10,
			expected:     -5,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			key := "TEST_INT_KEY"
			if tt.value != "" {
				os.Setenv(key, tt.value)
				defer os.Unsetenv(key)
			}

			got := getEnvAsInt(key, tt.defaultValue)
			if got != tt.expected {
				t.Errorf("getEnvAsInt() = %v, want %v", got, tt.expected)
			}
		})
	}
}

func TestGetEnvAsSlice(t *testing.T) {
	tests := []struct {
		name         string
		value        string
		defaultValue []string
		expected     []string
	}{
		{
			name:         "single value",
			value:        "10.0.0.0/8",
			defaultValue: []string{},
			expected:     []string{"10.0.0.0/8"},
		},
		{
			name:         "multiple values",
			value:        "10.0.0.0/8,172.16.0.0/12,192.168.0.0/16",
			defaultValue: []string{},
			expected:     []string{"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"},
		},
		{
			name:         "empty value",
			value:        "",
			defaultValue: []string{"default"},
			expected:     []string{"default"},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			key := "TEST_SLICE_KEY"
			if tt.value != "" {
				os.Setenv(key, tt.value)
				defer os.Unsetenv(key)
			}

			got := getEnvAsSlice(key, tt.defaultValue)

			if len(got) != len(tt.expected) {
				t.Errorf("getEnvAsSlice() length = %v, want %v", len(got), len(tt.expected))
				return
			}

			for i, v := range got {
				if v != tt.expected[i] {
					t.Errorf("getEnvAsSlice()[%d] = %v, want %v", i, v, tt.expected[i])
				}
			}
		})
	}
}

// cleanEnv removes all DYN-related env vars and returns a cleanup function
func cleanEnv() func() {
	vars := []string{
		"SERVER_PORT",
		"DATABASE_PATH",
		"TECHNITIUM_URL",
		"TECHNITIUM_USERNAME",
		"TECHNITIUM_PASSWORD",
		"TECHNITIUM_TOKEN",
		"BASE_DOMAIN",
		"SPACE_SUBDOMAIN",
		"RATE_LIMIT_PER_IP",
		"RATE_LIMIT_PER_TOKEN",
		"TRUSTED_PROXIES",
	}

	// Store old values
	oldValues := make(map[string]string)
	for _, v := range vars {
		if val, ok := os.LookupEnv(v); ok {
			oldValues[v] = val
			os.Unsetenv(v)
		}
	}

	// Return cleanup function
	return func() {
		for _, v := range vars {
			os.Unsetenv(v)
		}
		for v, val := range oldValues {
			os.Setenv(v, val)
		}
	}
}