package main

import (
	"regexp"
	"strings"
)

type CppParameter struct {
	ParameterName string
	ParameterType string
	Const         bool
	Pointer       bool
	PointerCount  int
	ByRef         bool
	Optional      bool

	QtCppOriginalType *CppParameter // If we rewrote QStringList->QList<String>, this field contains the original QStringList. Otherwise, it's blank
}

func (p *CppParameter) ApplyTypedef(matchedUnderlyingType CppParameter) {
	if p.QtCppOriginalType == nil {
		tmp := *p                  // Copy
		p.QtCppOriginalType = &tmp // Overwrite once only, at the earliest base type
	}
	p.ParameterType = matchedUnderlyingType.ParameterType

	// If this was a pointer to a typedef'd type, or a typedef of a pointer type, we need to preserve that
	p.Const = p.Const || matchedUnderlyingType.Const
	p.Pointer = p.Pointer || matchedUnderlyingType.Pointer
	p.PointerCount += matchedUnderlyingType.PointerCount
	p.ByRef = p.ByRef || matchedUnderlyingType.ByRef
	p.Optional = p.Optional || matchedUnderlyingType.Optional
}

func (p *CppParameter) PointerTo() CppParameter {
	ret := *p // Copy
	ret.Pointer = true
	ret.PointerCount++
	return ret
}

func (p *CppParameter) ConstCast(isConst bool) CppParameter {
	ret := *p // Copy
	ret.Const = isConst
	return ret
}

func (p *CppParameter) GetQtCppType() *CppParameter {
	if p.QtCppOriginalType != nil {
		return p.QtCppOriginalType
	}

	return p
}

func (p CppParameter) QFlagsOf() (CppParameter, bool) {

	if strings.HasPrefix(p.ParameterType, `QFlags<`) {
		ret := parseSingleTypeString(p.ParameterType[7 : len(p.ParameterType)-1])
		ret.ParameterName = p.ParameterName + "_qf"
		return ret, true
	}

	if under := p.QtCppOriginalType; under != nil {
		if strings.HasPrefix(under.ParameterType, `QFlags<`) {
			ret := parseSingleTypeString(under.ParameterType[7 : len(under.ParameterType)-1])
			ret.ParameterName = under.ParameterName + "_qf"
			return ret, true
		}
	}

	return CppParameter{}, false
}

func (p CppParameter) IsFlagType() bool {
	_, ok := p.QFlagsOf()
	return ok
}

func (p CppParameter) QtClassType() bool {

	// QtClassType returns false for our customized container types (QList,
	// QMap, QSet, etc)

	// Maybe if it's an inner class
	if _, ok := KnownClassnames[p.ParameterType]; ok {
		return true
	}

	if p.ParameterType == "Scintilla::Internal::Point" {
		return true
	}

	if p.ParameterType == "QString" || p.ParameterType == "QByteArray" {
		return true
	}

	return false
}

func (p CppParameter) IsKnownEnum() bool {
	_, ok := KnownEnums[p.ParameterType]
	return ok
}

func (p CppParameter) QListOf() (CppParameter, bool) {
	if strings.HasPrefix(p.ParameterType, "QList<") && strings.HasSuffix(p.ParameterType, `>`) {
		ret := parseSingleTypeString(p.ParameterType[6 : len(p.ParameterType)-1])
		ret.ParameterName = p.ParameterName + "_lv"
		return ret, true
	}

	if strings.HasPrefix(p.ParameterType, "QVector<") && strings.HasSuffix(p.ParameterType, `>`) {
		ret := parseSingleTypeString(p.ParameterType[8 : len(p.ParameterType)-1])
		ret.ParameterName = p.ParameterName + "_vv"
		return ret, true
	}

	return CppParameter{}, false
}

func (p CppParameter) QMapOf() (CppParameter, CppParameter, bool) {
	// n.b. Need to block QMap<k,v>::const_terator

	if strings.HasPrefix(p.ParameterType, `QMap<`) && strings.HasSuffix(p.ParameterType, `>`) {
		interior := tokenizeMultipleParameters(p.ParameterType[5 : len(p.ParameterType)-1])
		if len(interior) != 2 {
			panic("QMap<> has unexpected number of template arguments")
		}

		first := parseSingleTypeString(interior[0])
		first.ParameterName = p.ParameterName + "_mapkey"
		second := parseSingleTypeString(interior[1])
		second.ParameterName = p.ParameterName + "_mapval"
		return first, second, true
	}

	if strings.HasPrefix(p.ParameterType, `QHash<`) && strings.HasSuffix(p.ParameterType, `>`) {
		interior := tokenizeMultipleParameters(p.ParameterType[6 : len(p.ParameterType)-1])
		if len(interior) != 2 {
			panic("QHash<> has unexpected number of template arguments")
		}

		first := parseSingleTypeString(interior[0])
		first.ParameterName = p.ParameterName + "_hashkey"
		second := parseSingleTypeString(interior[1])
		second.ParameterName = p.ParameterName + "_hashval"
		return first, second, true
	}

	return CppParameter{}, CppParameter{}, false
}

func (p CppParameter) QPairOf() (CppParameter, CppParameter, bool) {
	if strings.HasPrefix(p.ParameterType, `QPair<`) && strings.HasSuffix(p.ParameterType, `>`) {
		interior := tokenizeMultipleParameters(p.ParameterType[6 : len(p.ParameterType)-1])
		if len(interior) != 2 {
			panic("QPair<> has unexpected number of template arguments")
		}

		first := parseSingleTypeString(interior[0])
		first.ParameterName = p.ParameterName + "_first"
		second := parseSingleTypeString(interior[1])
		second.ParameterName = p.ParameterName + "_second"
		return first, second, true
	}

	return CppParameter{}, CppParameter{}, false
}

func (p CppParameter) QSetOf() (CppParameter, bool) {
	if strings.HasPrefix(p.ParameterType, `QSet<`) {
		ret := parseSingleTypeString(p.ParameterType[5 : len(p.ParameterType)-1])
		ret.ParameterName = p.ParameterName + "_sv"
		return ret, true
	}

	return CppParameter{}, false
}

func (p CppParameter) QMultiMapOf() bool {
	if strings.HasPrefix(p.ParameterType, `QMultiMap<`) ||
		strings.HasPrefix(p.ParameterType, `QMultiHash<`) {
		return true
	}

	return false
}

func (p CppParameter) IntType() bool {

	if p.IsKnownEnum() {
		return true
	}

	switch p.ParameterType {
	case "int", "unsigned int", "uint",
		"short", "unsigned short", "ushort", "qint16", "quint16", "uint16_t", "int16_t",
		"qint8", "quint8",
		"unsigned char", "signed char", "uchar",
		"long", "unsigned long", "ulong", "qint32", "quint32", "int32_t", "uint32_t",
		"longlong", "ulonglong", "qlonglong", "qulonglong", "qint64", "quint64", "int64_t", "uint64_t", "long long", "unsigned long long",
		"qintptr", "quintptr", "uintptr_t", "intptr_t",
		"qsizetype", "size_t",
		"QIntegerForSizeof<void *>::Unsigned",
		"QIntegerForSizeof<void *>::Signed",
		"QIntegerForSizeof<std::size_t>::Signed",
		"qptrdiff", "ptrdiff_t",
		"double", "float", "qreal":
		return true

	case "char":
		// Only count char as an integer type with cast assertions if it's
		// not possibly a char* string in disguise
		// (However, unsigned chars are always like ints)
		return !p.Pointer

	default:
		return false
	}
}

func (p CppParameter) Void() bool {
	return p.ParameterType == "void" && !p.Pointer
}

type CppProperty struct {
	PropertyName string
	PropertyType string
	Visibility   string
}

type CppMethod struct {
	MethodName         string       // C++ method name, unless OverrideMethodName is set, in which case a nice alternative name
	OverrideMethodName string       // C++ method name, present only if we changed the target
	ReturnType         CppParameter // Name not used
	Parameters         []CppParameter
	IsStatic           bool
	IsSignal           bool
	IsConst            bool
	IsVirtual          bool
	IsPureVirtual      bool           // Virtual method was declared with = 0 i.e. there is no base method here to call
	IsProtected        bool           // If true, we can't call this method but we may still be able to overload it
	HiddenParams       []CppParameter // Populated if there is an overload with more parameters

	// Special quirks
	LinuxOnly                bool
	BecomesNonConstInVersion *string // "6,7"
}

func (m CppMethod) CppCallTarget() string {
	if m.OverrideMethodName != "" {
		return m.OverrideMethodName
	}
	return m.MethodName
}

func (m *CppMethod) Rename(newName string) {
	if m.OverrideMethodName == "" {
		m.OverrideMethodName = m.MethodName
	} else {
		// If it was already set, we're already a level of overload resolution deep - preserve it
	}

	m.MethodName = newName
}

func IsArgcArgv(params []CppParameter, pos int) bool {
	// Check if the arguments starting at position=pos are the argc/argv pattern.
	// QApplication/QGuiApplication constructors are the only expected example of this.
	return (len(params) > pos+1 &&
		params[pos].ParameterName == "argc" &&
		params[pos].ParameterType == "int" &&
		params[pos].ByRef &&
		params[pos+1].ParameterName == "argv" &&
		params[pos+1].ParameterType == "char") &&
		params[pos+1].Pointer &&
		params[pos+1].PointerCount == 2
}

func IsReceiverMethod(params []CppParameter, pos int) bool {
	// Check if the arguments starting at position=pos are the receiver/member pattern.
	// QMenu->addAction is the main example of this
	return (len(params) > pos+1 &&
		params[pos].ParameterName == "receiver" &&
		params[pos].ParameterType == "QObject" &&
		params[pos].Pointer &&
		params[pos+1].ParameterName == "member" &&
		params[pos+1].ParameterType == "char" &&
		params[pos+1].Pointer)
}

func (nm CppMethod) IsReceiverMethod() bool {
	// Returns true if any of the parameters use the receiever-method pattern
	for i := 0; i < len(nm.Parameters); i++ {
		if IsReceiverMethod(nm.Parameters, i) {
			return true
		}
	}
	return false
}

func (nm CppMethod) SafeMethodName() string {
	// Strip redundant Qt prefix, we know these are all Qt functions
	tmp := strings.TrimPrefix(nm.MethodName, "qt_")

	// Operator-overload methods have names not representable in binding
	// languages. Replace more specific cases first
	replacer := strings.NewReplacer(

		`==`, `Equal`,
		`!=`, `NotEqual`,
		`>=`, `GreaterOrEqual`,
		`<=`, `LesserOrEqual`,
		`=`, `Assign`,

		`<<`, `ShiftLeft`, // Qt classes use it more for stream functions e.g. in QDataStream
		`>>`, `ShiftRight`,
		`>`, `Greater`,
		`<`, `Lesser`,

		`+`, `Plus`,
		`-`, `Minus`,
		`*`, `Multiply`,
		`/`, `Divide`,
		`%`, `Modulo`,

		`&&`, `LogicalAnd`,
		`||`, `LogicalOr`,
		`!`, `Not`,
		`&`, `BitwiseAnd`,
		`|`, `BitwiseOr`,
		`~`, `BitwiseXor`,
		`^`, `BitwiseNot`,

		`->`, `PointerDereference`,
		`[]`, `Subscript`,
		`()`, `Call`,
	)
	tmp = replacer.Replace(tmp)

	// Also make the first letter uppercase so it becomes public in Go
	tmp = titleCase(tmp)

	// Also replace any underscore_case with CamelCase
	tmp = regexp.MustCompile(`_([a-z])`).ReplaceAllStringFunc(tmp, func(match string) string { return strings.ToUpper(match[1:]) })

	return tmp
}

type CppEnumEntry struct {
	EntryName  string
	EntryValue string
}

type CppEnum struct {
	EnumName       string
	UnderlyingType CppParameter
	Entries        []CppEnumEntry
}

func (e CppEnum) ShortEnumName() string {

	// Strip back one single :: pair from the generated variable name
	if nameParts := strings.Split(e.EnumName, `::`); len(nameParts) > 1 {
		nameParts = nameParts[0 : len(nameParts)-1]
		return strings.Join(nameParts, `::`)
	}

	// No change
	return e.EnumName
}

type CppClass struct {
	ClassName      string
	Abstract       bool
	Ctors          []CppMethod // only use the parameters
	DirectInherits []string    // other class names. This only includes direct inheritance - use AllInherits() to find recursive inheritance
	Methods        []CppMethod
	Props          []CppProperty
	CanDelete      bool

	ChildTypedefs  []CppTypedef
	ChildClassdefs []CppClass
	ChildEnums     []CppEnum
	PrivateMethods []string
}

// Virtual checks if the class has any virtual methods. This requires global
// state knowledge as virtual methods might have been inherited.
// C++ constructors cannot be virtual.
func (c *CppClass) VirtualMethods() []CppMethod {
	var ret []CppMethod
	var retNames = make(map[string]struct{}, 0) // if name is present, a child class found it first
	var block = slice_to_set(c.PrivateMethods)

	if len(c.Ctors) == 0 {
		// This class can't be constructed
		// Therefore there's no way to get a derived version of it for subclassing
		// (Unless we add custom constructors, but that seems like there would be
		// no in-Qt use for such a thing)
		// Pretend that this class is non-virtual
		return nil
	}

	// FIXME Allowing the subclassing of QAccessibleWidget compiles fine,
	// but, always gives a linker error:
	//
	//   /usr/lib/go-1.19/pkg/tool/linux_amd64/link: running g++ failed: exit status 1
	//   /usr/bin/ld: /tmp/go-link-1745036494/000362.o: in function `MiqtVirtualQAccessibleWidget::MiqtVirtualQAccessibleWidget(QWidget*)':
	//   undefined reference to `vtable for MiqtVirtualQAccessibleWidget'
	//
	// An undefined vtable usually indicates that the virtual class is missing
	// definitions for some virtual methods, but AFAICT we have complete coverage.
	if c.ClassName == "QAccessibleWidget" {
		return nil
	}

	for _, m := range c.Methods {
		if !m.IsVirtual {
			continue
		}
		if m.IsSignal {
			continue
		}
		if !AllowVirtual(m) {
			continue
		}

		ret = append(ret, m)
		retNames[m.CppCallTarget()] = struct{}{}
	}

	// Only allow virtual overrides for direct inherits, not all inherits -
	// Go will automatically allow virtual overrides for the base type because
	// the parent struct is nested
	for _, inh := range c.DirectInherits { // AllInherits() {
		cinfo, ok := KnownClassnames[inh]
		if !ok {
			panic("Class " + c.ClassName + " inherits from unknown class " + inh)
		}

		for _, m := range cinfo.Class.Methods {
			if !m.IsVirtual {
				continue
			}
			if m.IsSignal {
				continue
			}
			if !AllowVirtual(m) {
				continue
			}
			if _, ok := retNames[m.CppCallTarget()]; ok {
				continue // Already found in a child class
			}

			// It's possible that a child class marked a parent method as private
			// (e.g. Qt 5 QAbstractTableModel marks parent() as private)
			// But then we find the protected version further down
			// Use a blocklist to prevent exposing any deeper methods in the call chain
			if _, ok := block[m.MethodName]; ok {
				continue // Marked as private in a child class
			}

			// The class info we loaded has not had all typedefs applied to it
			// m is copied by value. Mutate it
			applyTypedefs_Method(&m)
			// Same with astTransformBlocklist
			if !blocklist_MethodAllowed(&m) {
				continue
			}

			ret = append(ret, m)
			retNames[m.CppCallTarget()] = struct{}{}
		}

		// Append this parent's private-virtuals to blocklist so that we
		// do not consider them for grandparent classes
		for _, privMethod := range c.PrivateMethods {
			block[privMethod] = struct{}{}
		}
	}

	return ret
}

// AllInherits recursively finds and lists all the parent classes of this class.
func (c *CppClass) AllInherits() []string {
	var ret []string

	// FIXME prevent duplicates arising from diamond inheritance

	for _, baseClass := range c.DirectInherits {

		ret = append(ret, baseClass)

		// And everything that class inherits - unless - we've seen it before
		baseClassInfo, ok := KnownClassnames[baseClass]
		if !ok {
			panic("Class " + c.ClassName + " inherits from unknown class " + baseClass)
		}

		recurseInfo := baseClassInfo.Class.AllInherits()
		for _, childClass := range recurseInfo {
			ret = append(ret, childClass)
		}
	}

	return ret
}

type CppTypedef struct {
	Alias          string
	UnderlyingType CppParameter
}

type CppParsedHeader struct {
	Filename string
	Typedefs []CppTypedef
	Enums    []CppEnum
	Classes  []CppClass
}

func (c CppParsedHeader) Empty() bool {
	// If there are only typedefs, that still counts as empty since typedefs
	// are fully resolved inside genbindings, not exposed in MIQT classes

	return len(c.Enums) == 0 && len(c.Classes) == 0
}

func (c *CppParsedHeader) AddContentFrom(other *CppParsedHeader) {
	c.Classes = append(c.Classes, other.Classes...)
	c.Enums = append(c.Enums, other.Enums...)
	c.Typedefs = append(c.Typedefs, other.Typedefs...)
}