package serviceadapter

import (
	"testing"
)

func TestValidateString(t *testing.T) {
	schema := &FieldSchema{Type: "string"}
	v := &Validator{schema: schema}

	errs := v.Validate("hello")
	if len(errs) != 0 {
		t.Errorf("expected no errors for valid string, got %v", errs)
	}

	errs = v.Validate(42)
	if len(errs) == 0 {
		t.Errorf("expected error for non-string")
	}
	if len(errs) > 0 && !stringContains(errs[0].Reason, "type_mismatch") {
		t.Errorf("expected type_mismatch error, got %s", errs[0].Reason)
	}
}

func TestValidateNumber(t *testing.T) {
	schema := &FieldSchema{Type: "number"}
	v := &Validator{schema: schema}

	errs := v.Validate(42.0)
	if len(errs) != 0 {
		t.Errorf("expected no errors for float64, got %v", errs)
	}

	errs = v.Validate("not a number")
	if len(errs) == 0 {
		t.Errorf("expected error for non-number")
	}
}

func TestValidateNullable(t *testing.T) {
	schemaNullable := &FieldSchema{Type: "string", Nullable: true}
	vNullable := &Validator{schema: schemaNullable}

	errs := vNullable.Validate(nil)
	if len(errs) != 0 {
		t.Errorf("expected no errors for null on nullable field, got %v", errs)
	}

	schemaNotNullable := &FieldSchema{Type: "string", Nullable: false}
	vNotNullable := &Validator{schema: schemaNotNullable}

	errs = vNotNullable.Validate(nil)
	if len(errs) == 0 {
		t.Errorf("expected error for null on non-nullable field")
	}
}

func TestValidateObject(t *testing.T) {
	schema := &FieldSchema{
		Type:     "object",
		Required: []string{"name"},
		Fields: map[string]FieldSchema{
			"name": {Type: "string"},
			"age":  {Type: "number"},
		},
	}
	v := &Validator{schema: schema}

	// Valid object
	obj := map[string]interface{}{
		"name": "Alice",
		"age":  30.0,
	}
	errs := v.Validate(obj)
	if len(errs) != 0 {
		t.Errorf("expected no errors for valid object, got %v", errs)
	}

	// Missing required field
	objMissing := map[string]interface{}{
		"age": 30.0,
	}
	errs = v.Validate(objMissing)
	if len(errs) == 0 {
		t.Errorf("expected error for missing required field")
	}
	if len(errs) > 0 && errs[0].Reason != "missing" {
		t.Errorf("expected 'missing' error, got %s", errs[0].Reason)
	}

	// Type mismatch
	objBadType := map[string]interface{}{
		"name": "Alice",
		"age":  "thirty",
	}
	errs = v.Validate(objBadType)
	if len(errs) == 0 {
		t.Errorf("expected error for type mismatch")
	}
}

func TestValidateObjectStrict(t *testing.T) {
	schema := &FieldSchema{
		Type:   "object",
		Strict: true,
		Fields: map[string]FieldSchema{
			"name": {Type: "string"},
		},
	}
	v := &Validator{schema: schema}

	// Unknown field rejected in strict mode
	obj := map[string]interface{}{
		"name":     "Alice",
		"unknown": "field",
	}
	errs := v.Validate(obj)
	if len(errs) == 0 {
		t.Errorf("expected error for unknown field in strict mode")
	}
	found := false
	for _, err := range errs {
		if err.Reason == "unknown_field" {
			found = true
			break
		}
	}
	if !found {
		t.Errorf("expected unknown_field error")
	}
}

func TestValidateArray(t *testing.T) {
	schema := &FieldSchema{
		Type: "array",
		Items: &FieldSchema{
			Type: "string",
		},
	}
	v := &Validator{schema: schema}

	// Valid array
	arr := []interface{}{"a", "b", "c"}
	errs := v.Validate(arr)
	if len(errs) != 0 {
		t.Errorf("expected no errors for valid string array, got %v", errs)
	}

	// Invalid element type
	arrBad := []interface{}{"a", 42, "c"}
	errs = v.Validate(arrBad)
	if len(errs) == 0 {
		t.Errorf("expected error for wrong type in array")
	}
}

func TestValidateArrayOfObjects(t *testing.T) {
	schema := &FieldSchema{
		Type: "array",
		Items: &FieldSchema{
			Type: "object",
			Fields: map[string]FieldSchema{
				"id":   {Type: "number"},
				"name": {Type: "string"},
			},
		},
	}
	v := &Validator{schema: schema}

	arr := []interface{}{
		map[string]interface{}{"id": 1.0, "name": "Alice"},
		map[string]interface{}{"id": 2.0, "name": "Bob"},
	}
	errs := v.Validate(arr)
	if len(errs) != 0 {
		t.Errorf("expected no errors for valid array of objects, got %v", errs)
	}
}

func TestValidateNoSchema(t *testing.T) {
	// No schema means no validation
	v := &Validator{schema: nil}

	errs := v.Validate(map[string]interface{}{"anything": "goes"})
	if len(errs) != 0 {
		t.Errorf("expected no errors when schema is nil")
	}
}

func TestParseSchema(t *testing.T) {
	schema, err := parseSchema("name: string, age: number")
	if err != nil {
		t.Fatalf("parse error: %v", err)
	}

	if schema.Type != "object" {
		t.Errorf("expected type object, got %s", schema.Type)
	}

	if len(schema.Fields) != 2 {
		t.Errorf("expected 2 fields, got %d", len(schema.Fields))
	}

	if f, ok := schema.Fields["name"]; !ok || f.Type != "string" {
		t.Errorf("expected name: string in parsed schema")
	}
}

func stringContains(s, substr string) bool {
	for i := 0; i < len(s); i++ {
		if i+len(substr) <= len(s) && s[i:i+len(substr)] == substr {
			return true
		}
	}
	return false
}