// GoTypeRef returns the Go code that refers to the Go type which matches the given data type
// (the part that comes after `var foo`)
// required only applies when referring to a user type that is an object defined inline. In this
// case the type (Object) does not carry the required field information defined in the parent
// (anonymous) attribute.
// tabs is used to properly tabulate the object struct fields and only applies to this case.
// This function assumes the type is in the same package as the code accessing it.
func GoTypeRef(t design.DataType, required []string, tabs int, private bool) string {
	tname := GoTypeName(t, required, tabs, private)
	if t.IsObject() {
		return "*" + tname
	}
	return tname
}

// cmdFieldType computes the Go type name used to store command flags of the given design type.
func cmdFieldType(t design.DataType, point bool) string {
	var pointer, suffix string
	if point && !t.IsArray() {
		pointer = "*"
	}
	suffix = codegen.GoNativeType(t)
	return pointer + suffix
}

// GoTypeRef returns the Go code that refers to the Go type which matches the given data type
// (the part that comes after `var foo`)
// required only applies when referring to a user type that is an object defined inline. In this
// case the type (Object) does not carry the required field information defined in the parent
// (anonymous) attribute.
// tabs is used to properly tabulate the object struct fields and only applies to this case.
// This function assumes the type is in the same package as the code accessing it.
func GoTypeRef(t design.DataType, required []string, tabs int, private bool) string {
	tname := GoTypeName(t, required, tabs, private)
	if mt, ok := t.(*design.MediaTypeDefinition); ok {
		if mt.IsError() {
			return "error"
		}
	}
	if t.IsObject() {
		return "*" + tname
	}
	return tname
}

func isArrayOfType(array design.DataType, kinds ...design.Kind) bool {
	if !array.IsArray() {
		return false
	}
	kind := array.ToArray().ElemType.Type.Kind()
	for _, t := range kinds {
		if t == kind {
			return true
		}
	}
	return false
}

// GoPackageTypeRef returns the Go code that refers to the Go type which matches the given data type.
// versioned indicates whether the type is being referenced from a version package (true) or the
// default package defPkg (false).
// required only applies when referring to a user type that is an object defined inline. In this
// case the type (Object) does not carry the required field information defined in the parent
// (anonymous) attribute.
// tabs is used to properly tabulate the object struct fields and only applies to this case.
func GoPackageTypeRef(t design.DataType, required []string, versioned bool, defPkg string, tabs int) string {
	switch t.(type) {
	case *design.UserTypeDefinition, *design.MediaTypeDefinition:
		var prefix string
		if t.IsObject() {
			prefix = "*"
		}
		return prefix + GoPackageTypeName(t, required, versioned, defPkg, tabs)
	case design.Object:
		return "*" + GoPackageTypeName(t, required, versioned, defPkg, tabs)
	default:
		return GoPackageTypeName(t, required, versioned, defPkg, tabs)
	}
}

// printVal prints the given value corresponding to the given data type.
// The value is already checked for the compatibility with the data type.
func printVal(t design.DataType, val interface{}) string {
	switch {
	case t.IsPrimitive():
		// For primitive types, simply print the value
		s := fmt.Sprintf("%#v", val)
		if t == design.DateTime {
			s = fmt.Sprintf("time.Parse(time.RFC3339, %s)", s)
		}
		return s
	case t.IsHash():
		// The input is a hash
		h := t.ToHash()
		hval := val.(map[interface{}]interface{})
		if len(hval) == 0 {
			return fmt.Sprintf("%s{}", GoTypeName(t, nil, 0, false))
		}
		var buffer bytes.Buffer
		buffer.WriteString(fmt.Sprintf("%s{", GoTypeName(t, nil, 0, false)))
		for k, v := range hval {
			buffer.WriteString(fmt.Sprintf("%s: %s, ", printVal(h.KeyType.Type, k), printVal(h.ElemType.Type, v)))
		}
		buffer.Truncate(buffer.Len() - 2) // remove ", "
		buffer.WriteString("}")
		return buffer.String()
	case t.IsArray():
		// Input is an array
		a := t.ToArray()
		aval := val.([]interface{})
		if len(aval) == 0 {
			return fmt.Sprintf("%s{}", GoTypeName(t, nil, 0, false))
		}
		var buffer bytes.Buffer
		buffer.WriteString(fmt.Sprintf("%s{", GoTypeName(t, nil, 0, false)))
		for _, e := range aval {
			buffer.WriteString(fmt.Sprintf("%s, ", printVal(a.ElemType.Type, e)))
		}
		buffer.Truncate(buffer.Len() - 2) // remove ", "
		buffer.WriteString("}")
		return buffer.String()
	default:
		// shouldn't happen as the value's compatibility is already checked.
		panic("unknown type")
	}
}

// cmdFieldTypeString computes the Go type name used to store command flags of the given design type. Complex types are String
func cmdFieldTypeString(t design.DataType, point bool) string {
	var pointer, suffix string
	if point && !t.IsArray() {
		pointer = "*"
	}
	if t.Kind() == design.UUIDKind || t.Kind() == design.DateTimeKind || t.Kind() == design.AnyKind || t.Kind() == design.NumberKind || t.Kind() == design.BooleanKind {
		suffix = "string"
	} else if isArrayOfType(t, design.UUIDKind, design.DateTimeKind, design.AnyKind, design.NumberKind, design.BooleanKind) {
		suffix = "[]string"
	} else {
		suffix = codegen.GoNativeType(t)
	}
	return pointer + suffix
}

// cmdFieldType computes the Go type name used to store command flags of the given design type.
func cmdFieldType(t design.DataType) string {
	if t.Kind() == design.DateTimeKind || t.Kind() == design.UUIDKind {
		return "string"
	}
	return codegen.GoNativeType(t)
}

// qualifiedTypeName returns the qualified type name for the given data type.
// This is useful in reporting types in error messages.
// (e.g) array<string>, hash<string, string>, hash<string, array<int>>
func qualifiedTypeName(t design.DataType) string {
	switch t.Kind() {
	case design.DateTimeKind:
		return "datetime"
	case design.ArrayKind:
		return fmt.Sprintf("%s<%s>", t.Name(), qualifiedTypeName(t.ToArray().ElemType.Type))
	case design.HashKind:
		h := t.ToHash()
		return fmt.Sprintf("%s<%s, %s>",
			t.Name(),
			qualifiedTypeName(h.KeyType.Type),
			qualifiedTypeName(h.ElemType.Type),
		)
	}
	return t.Name()
}