package smartconfig

import (
	"os"
	"regexp"
	"strings"
	"testing"
)

func TestEnvResolver(t *testing.T) {
	_ = os.Setenv("TEST_VAR", "test-value")
	defer func() { _ = os.Unsetenv("TEST_VAR") }()

	resolver := &EnvResolver{}
	result, err := resolver.Resolve("TEST_VAR")
	if err != nil {
		t.Fatalf("Failed to resolve env var: %v", err)
	}
	if result != "test-value" {
		t.Errorf("Expected 'test-value', got '%s'", result)
	}
}

func TestExecResolver(t *testing.T) {
	resolver := &ExecResolver{}
	result, err := resolver.Resolve("echo hello")
	if err != nil {
		t.Fatalf("Failed to execute command: %v", err)
	}
	if result != "hello" {
		t.Errorf("Expected 'hello', got '%s'", result)
	}
}

func TestFileResolver(t *testing.T) {
	resolver := &FileResolver{}
	result, err := resolver.Resolve("./test/machine-id")
	if err != nil {
		t.Fatalf("Failed to read file: %v", err)
	}
	if result != "test-machine-123456789" {
		t.Errorf("Expected 'test-machine-123456789', got '%s'", result)
	}
}

func TestJSONResolver(t *testing.T) {
	resolver := &JSONResolver{}

	// Test simple path
	result, err := resolver.Resolve("./test/hosts.json:.")
	if err != nil {
		t.Fatalf("Failed to resolve JSON: %v", err)
	}
	if !strings.Contains(result, "tls_sni_host") {
		t.Errorf("Expected JSON output to contain 'tls_sni_host', got '%s'", result)
	}
}

func TestYAMLResolver(t *testing.T) {
	resolver := &YAMLResolver{}

	// Test simple path
	result, err := resolver.Resolve("./test/data.yaml:.")
	if err != nil {
		t.Fatalf("Failed to resolve YAML: %v", err)
	}
	if !strings.Contains(result, "database") {
		t.Errorf("Expected YAML output to contain 'database', got '%s'", result)
	}
}

func TestInterpolateBasic(t *testing.T) {
	_ = os.Setenv("BASIC", "value")
	defer func() { _ = os.Unsetenv("BASIC") }()

	config := New()
	content := "test: ${ENV:BASIC}"
	err := config.LoadFromReader(strings.NewReader(content))
	if err != nil {
		t.Fatalf("Failed to load config: %v", err)
	}

	value, err := config.GetString("test")
	if err != nil {
		t.Fatalf("Failed to get test value: %v", err)
	}
	if value != "value" {
		t.Errorf("Expected 'value', got '%s'", value)
	}
}

func TestInterpolateMethod(t *testing.T) {
	config := New()
	_ = os.Setenv("FOO", "bar")
	defer func() { _ = os.Unsetenv("FOO") }()

	// Test direct interpolation
	result, _ := config.interpolate("${ENV:FOO}", 0)
	if result != "\"bar\"" {
		t.Errorf("Expected '\"bar\"', got '%s'", result)
	}
}

func TestInterpolateSimple(t *testing.T) {
	config := New()
	_ = os.Setenv("TEST", "value")
	defer func() { _ = os.Unsetenv("TEST") }()

	// Verify regex finds the match
	re := regexp.MustCompile(`\$\{([^:]+?):(.*?)\}`)
	matches := re.FindAllStringSubmatch("${ENV:TEST}", -1)
	if len(matches) == 0 {
		t.Fatal("Regex didn't find any matches")
	}

	// Test simple interpolation
	result, _ := config.interpolate("${ENV:TEST}", 0)
	if result != "\"value\"" {
		t.Errorf("Simple interpolation failed: expected '\"value\"', got '%s'", result)
	}
}

func TestInterpolateStep(t *testing.T) {
	config := New()

	// Set env vars
	_ = os.Setenv("BAR", "value1")
	_ = os.Setenv("FOO_value1", "success")
	defer func() {
		_ = os.Unsetenv("BAR")
		_ = os.Unsetenv("FOO_value1")
	}()

	// Step 1: Inner interpolation should resolve first
	step1 := "${ENV:BAR}"
	result1, _ := config.interpolate(step1, 0)
	if result1 != "\"value1\"" {
		t.Errorf("Step 1 failed: expected '\"value1\"', got '%s'", result1)
	}

	// Step 2: With the result, build the outer
	step2 := "${ENV:FOO_value1}"
	result2, _ := config.interpolate(step2, 0)
	if result2 != "\"success\"" {
		t.Errorf("Step 2 failed: expected '\"success\"', got '%s'", result2)
	}

	// Step 3: Full nested
	full := "${ENV:FOO_${ENV:BAR}}"
	result3, _ := config.interpolate(full, 0)
	if result3 != "\"success\"" {
		t.Errorf("Full nested failed: expected '\"success\"', got '%s'", result3)
	}
}

func TestRegexPattern(t *testing.T) {
	re := regexp.MustCompile(`\$\{([^:]+?):(.*?)\}`)

	// Test simple case
	matches := re.FindStringSubmatch("${ENV:FOO}")
	if len(matches) != 3 || matches[1] != "ENV" || matches[2] != "FOO" {
		t.Errorf("Simple pattern failed: %v", matches)
	}

	// Test nested case - this will fail with current regex
	input := "${ENV:FOO_${ENV:BAR}}"
	matches = re.FindStringSubmatch(input)
	if len(matches) == 3 {
		t.Logf("Nested pattern matches: resolver=%s, value=%s", matches[1], matches[2])
		// This will show that value is "FOO_${ENV:BAR" which is wrong
	}
}

func TestInterpolateNested(t *testing.T) {
	config := New()
	_ = os.Setenv("INNER", "BAR")
	_ = os.Setenv("FOO_BAR", "success")
	defer func() {
		_ = os.Unsetenv("INNER")
		_ = os.Unsetenv("FOO_BAR")
	}()

	// Test nested interpolation directly
	result, _ := config.interpolate("${ENV:FOO_${ENV:INNER}}", 0)
	if result != "\"success\"" {
		t.Errorf("Expected '\"success\"', got '%s'", result)
	}
}

func TestSimpleNestedInterpolation(t *testing.T) {
	_ = os.Setenv("SUFFIX", "BAR")
	_ = os.Setenv("FOO_BAR", "success")
	defer func() {
		_ = os.Unsetenv("SUFFIX")
		_ = os.Unsetenv("FOO_BAR")
	}()

	config := New()
	content := "test: ${ENV:FOO_${ENV:SUFFIX}}"
	err := config.LoadFromReader(strings.NewReader(content))
	if err != nil {
		t.Fatalf("Failed to load config: %v", err)
	}

	value, err := config.GetString("test")
	if err != nil {
		t.Fatalf("Failed to get test value: %v", err)
	}
	if value != "success" {
		t.Errorf("Expected 'success', got '%s'", value)
	}
}

func TestConfigInterpolation(t *testing.T) {
	// Set up environment
	_ = os.Setenv("TEST_APP_NAME", "myapp")
	_ = os.Setenv("TEST_PORT", "8080")
	_ = os.Setenv("TEST_ENV_SUFFIX", "VALUE")
	_ = os.Setenv("NESTED_VALUE", "nested-result")
	defer func() {
		_ = os.Unsetenv("TEST_APP_NAME")
		_ = os.Unsetenv("TEST_PORT")
		_ = os.Unsetenv("TEST_ENV_SUFFIX")
		_ = os.Unsetenv("NESTED_VALUE")
	}()

	config := New()
	err := config.LoadFromFile("./test/config.yaml")
	if err != nil {
		t.Fatalf("Failed to load config: %v", err)
	}

	// Test basic interpolation
	name, err := config.GetString("name")
	if err != nil {
		t.Fatalf("Failed to get name: %v", err)
	}
	if name != "myapp" {
		t.Errorf("Expected name 'myapp', got '%s'", name)
	}

	// Test exec interpolation
	if serverData, ok := config.data["server"].(map[string]interface{}); ok {
		if hostname, ok := serverData["hostname"].(string); ok {
			if hostname == "" {
				t.Errorf("Expected hostname to be non-empty")
			}
		} else {
			t.Errorf("Expected server.hostname to be a string")
		}
	} else {
		t.Errorf("Expected server to be a map")
	}

	// Test file interpolation
	if machineData, ok := config.data["machine"].(map[string]interface{}); ok {
		if id, ok := machineData["id"].(string); ok {
			if id != "test-machine-123456789" {
				t.Errorf("Expected machine.id 'test-machine-123456789', got '%s'", id)
			}
		}
	}

	// Test nested interpolation
	if nestedData, ok := config.data["nested"].(map[string]interface{}); ok {
		if value, ok := nestedData["value"].(string); ok {
			if value != "nested-result" {
				t.Errorf("Expected nested.value 'nested-result', got '%s'", value)
			}
		}
	}

	// Test environment injection
	injectedVar := os.Getenv("INJECTED_VAR")
	if injectedVar != "injected-value" {
		t.Errorf("Expected INJECTED_VAR to be 'injected-value', got '%s'", injectedVar)
	}

	computedVar := os.Getenv("COMPUTED_VAR")
	if computedVar != "computed" {
		t.Errorf("Expected COMPUTED_VAR to be 'computed', got '%s'", computedVar)
	}
}

func TestRecursionLimit(t *testing.T) {
	config := New()

	// Create a deeply nested interpolation that hits the recursion limit
	// This has 4 levels, but our max is 3
	content := "value: ${ENV:LEVEL1_${ENV:LEVEL2_${ENV:LEVEL3_${ENV:LEVEL4}}}}"

	// Set up environment variables for a complete chain
	_ = os.Setenv("LEVEL4", "END")
	_ = os.Setenv("LEVEL3_END", "3")
	_ = os.Setenv("LEVEL2_3", "2")
	_ = os.Setenv("LEVEL1_2", "final")
	// Also set the partial resolution that would be needed at depth 3
	_ = os.Setenv("LEVEL3_${ENV:LEVEL4}", "depth3value")
	_ = os.Setenv("LEVEL2_depth3value", "depth2value")
	_ = os.Setenv("LEVEL1_depth2value", "final_with_limit")
	defer func() {
		_ = os.Unsetenv("LEVEL4")
		_ = os.Unsetenv("LEVEL3_END")
		_ = os.Unsetenv("LEVEL2_3")
		_ = os.Unsetenv("LEVEL1_2")
		_ = os.Unsetenv("LEVEL3_${ENV:LEVEL4}")
		_ = os.Unsetenv("LEVEL2_depth3value")
		_ = os.Unsetenv("LEVEL1_depth2value")
	}()

	err := config.LoadFromReader(strings.NewReader(content))
	if err != nil {
		t.Fatalf("Failed to load config: %v", err)
	}

	// At depth 3, interpolation stops and returns the partial result
	// So LEVEL3_${ENV:LEVEL4} is used as the literal key, giving "depth3value"
	// Then LEVEL2_depth3value gives "depth2value"
	// Finally LEVEL1_depth2value gives "final_with_limit"
	value, _ := config.GetString("value")
	if value != "final_with_limit" {
		t.Errorf("Expected value to be 'final_with_limit' (recursion limit reached), got '%s'", value)
	}
}

func TestInvalidResolverFormat(t *testing.T) {
	tests := []struct {
		name     string
		resolver Resolver
		input    string
	}{
		{"JSON missing path", &JSONResolver{}, "file.json"},
		{"YAML missing path", &YAMLResolver{}, "file.yaml"},
		{"Vault missing key", &VaultResolver{}, "secret/data/myapp"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			_, err := tt.resolver.Resolve(tt.input)
			if err == nil {
				t.Errorf("Expected error for invalid format")
			}
		})
	}
}

func TestUnknownResolver(t *testing.T) {
	config := New()
	content := "value: ${UNKNOWN:test}"

	// Unknown resolver should cause an error
	err := config.LoadFromReader(strings.NewReader(content))
	if err == nil {
		t.Fatal("Expected error for unknown resolver, but got none")
	}
	if !strings.Contains(err.Error(), "unknown resolver: UNKNOWN") {
		t.Errorf("Expected error to mention unknown resolver UNKNOWN, got: %v", err)
	}
}