use pest::Parser;

pub mod build;
pub mod unparse;

// Operators

#[derive(Debug)]
pub enum Operator {
    Binary(BinaryOperator),
    PrefixUnary(PrefixUnaryOperator),
    SuffixUnary(SuffixUnaryOperator),
}

#[derive(Debug)]
pub enum BinaryOperator {
    Or,
    And,
    EqualTo,
    NotEqualTo,
    Greater,
    Less,
    GreaterEqual,
    LessEqual,
    Add,
    Subtract,
    Multiply,
    Divide,
    Modulo,
    LeftShift,
    RightShift,
}

#[derive(Debug)]
pub enum PrefixUnaryOperator {
    Spread,
    Borrow,
    BorrowMut,
    Not,
    Negative,
}

#[derive(Debug)]
pub enum SuffixUnaryOperator {
    PlusPlus,
    MinusMinus,
}

/* Names */

#[derive(Debug, Clone)]
pub struct Identifier {
    pub name: String,
}

#[derive(Debug)]
pub struct FullyQualifiedName(pub Vec<Identifier>);

/* Type Use */

#[derive(Debug)]
pub enum TypeUse {
    Void,
    InterfaceOrClass(InterfaceOrClassTypeUse),
    Tuple(TupleTypeUse),
    Function(FunctionTypeUse),
}

#[derive(Debug)]
pub struct InterfaceOrClassTypeUse {
    pub borrow_count: usize,
    pub is_mutable: bool,
    pub fqn: FullyQualifiedName,
    pub generics: GenericArguments,
}

#[derive(Debug)]
pub struct TupleTypeUse {
    pub borrow_count: usize,
    pub is_mutable: bool,
    pub arguments: TupleArguments,
}

#[derive(Debug)]
pub struct FunctionTypeUse {
    pub borrow_count: usize,
    pub function_modifier: Option<FunctionTypeModifier>,
    pub generics: GenericParameters,
    pub parameters: Parameters,
    pub return_type: ReturnType,
}

// Generic arguments

#[derive(Debug)]
pub struct GenericArguments(pub Vec<TypeUse>);

impl GenericArguments {
    pub fn is_empty(&self) -> bool {
        self.0.is_empty()
    }
}

impl Default for GenericArguments {
    fn default() -> Self {
        GenericArguments(Vec::new())
    }
}

/* Generic parameters */

#[derive(Debug)]
pub struct GenericParameters(pub Vec<GenericParameter>);

impl GenericParameters {
    pub fn is_empty(&self) -> bool {
        self.0.is_empty()
    }
}

impl Default for GenericParameters {
    fn default() -> Self {
        GenericParameters(Vec::new())
    }
}

#[derive(Debug)]
pub struct GenericParameter(pub Identifier);

/* Tuple Arguments */

#[derive(Debug)]
pub struct TupleArguments(pub Vec<TypeUse>);

/* Implements List */

#[derive(Debug)]
pub struct ImplementsList(pub Vec<TypeUse>);

impl ImplementsList {
    pub fn is_empty(&self) -> bool {
        self.0.is_empty()
    }
}

impl Default for ImplementsList {
    fn default() -> Self {
        ImplementsList(Vec::new())
    }
}

/* Function Type Modifier and Function Modifier */

#[derive(Debug)]
pub enum FunctionTypeModifier {
    Cons,
    MutRef,
    Mut,
    Ref,
}

/* Function Parameters */

#[derive(Debug)]
pub struct Parameters(pub Vec<Parameter>);

impl Parameters {
    pub fn is_empty(&self) -> bool {
        self.0.is_empty()
    }
}

impl Default for Parameters {
    fn default() -> Self {
        Parameters(Vec::new())
    }
}

#[derive(Debug)]
pub struct Parameter {
    identifier: Identifier,
    type_use: TypeUse,
}

/* Return Type */

#[derive(Debug)]
pub struct ReturnType {
    pub declared_type: Box<TypeUse>,
    pub references: References,
}

impl ReturnType {
    pub fn void() -> Self {
        ReturnType {
            declared_type: Box::new(TypeUse::Void),
            references: References::default()
        }
    }
}

/* References */

#[derive(Debug)]
pub struct References(pub Vec<Reference>);

impl References {
    pub fn is_empty(&self) -> bool {
        self.0.is_empty()
    }
}

impl Default for References {
    fn default() -> Self {
        References(Vec::new())
    }
}

#[derive(Debug)]
pub struct Reference(pub Identifier);

/* Top-level construct */

#[derive(Debug)]
pub struct CompilationUnit {
    pub namespace: Option<FullyQualifiedName>,
    pub declarations: Vec<ModuleLevelDeclaration>,
}

// Declarations allowed in each level

#[derive(Debug)]
pub enum ModuleLevelDeclaration {
    Module(ModuleDeclaration),
    Interface(InterfaceDeclaration),
    Class(ClassDeclaration),
    Function(FunctionDefinition),
    PlatformFunction(PlatformFunctionDeclaration),
}

#[derive(Debug)]
pub enum InterfaceLevelDeclaration {
    Module(ModuleDeclaration),
    Interface(InterfaceDeclaration),
    Class(ClassDeclaration),
    Function(InterfaceFunctionDeclaration),
    OperatorFunction(InterfaceOperatorFunctionDeclaration),
}

#[derive(Debug)]
pub enum ClassLevelDeclaration {
    Module(ModuleDeclaration),
    Interface(InterfaceDeclaration),
    Class(ClassDeclaration),
    Function(FunctionDefinition),
    OperatorFunction(OperatorFunctionDefinition),
    PlatformFunction(PlatformFunctionDeclaration),
    Property(PropertyDeclaration),
    Field(FieldDeclaration),
}

// Declarations

#[derive(Debug)]
pub struct ModuleDeclaration {
    pub is_public: bool,
    pub identifier: Identifier,
    pub declarations: Vec<ModuleLevelDeclaration>,
}

#[derive(Debug)]
pub struct InterfaceDeclaration {
    pub is_public: bool,
    pub identifier: Identifier,
    pub generics: GenericParameters,
    pub implements: ImplementsList,
    pub declarations: Vec<InterfaceLevelDeclaration>,
}

#[derive(Debug)]
pub struct ClassDeclaration {
    pub is_public: bool,
    pub identifier: Identifier,
    pub generics: GenericParameters,
    pub class_constructor: Option<ClassConstructor>,
    pub implements: ImplementsList,
    pub declarations: Vec<ClassLevelDeclaration>,
}

// Function declarations and components

#[derive(Debug)]
pub struct FunctionDefinition {
    pub is_public: bool,
    pub modifier: Option<FunctionModifier>,
    pub generics: GenericParameters,
    pub identifier: Identifier,
    pub parameters: Parameters,
    pub return_type: ReturnType,
    pub body: FunctionBody,
}

#[derive(Debug)]
pub struct OperatorFunctionDefinition {
    pub is_public: bool,
    pub modifier: Option<FunctionModifier>,
    pub generics: GenericParameters,
    pub operator: Operator,
    pub parameters: Parameters,
    pub return_type: ReturnType,
    pub body: FunctionBody,
}

#[derive(Debug)]
pub struct PlatformFunctionDeclaration {
    pub is_public: bool,
    pub modifier: Option<FunctionModifier>,
    pub generics: GenericParameters,
    pub identifier: Identifier,
    pub parameters: Parameters,
    pub return_type: ReturnType,
}

#[derive(Debug)]
pub struct InterfaceFunctionDeclaration {
    pub modifier: Option<FunctionModifier>,
    pub generics: GenericParameters,
    pub identifier: Identifier,
    pub parameters: Parameters,
    pub return_type: ReturnType,
    pub body: Option<FunctionBody>,
}

#[derive(Debug)]
pub struct InterfaceOperatorFunctionDeclaration {
    pub modifier: Option<FunctionModifier>,
    pub generics: GenericParameters,
    pub operator: Operator,
    pub parameters: Parameters,
    pub return_type: ReturnType,
    pub body: Option<FunctionBody>,
}

#[derive(Debug)]
pub enum FunctionModifier {
    Static,
    Cons,
    Mut,
    Ref,
    MutRef,
}

#[derive(Debug)]
pub enum FunctionBody {
    Equals(Expression),
    Block(BlockStatement),
    Alias(Identifier),
}

// Class components

#[derive(Debug)]
pub struct ClassConstructor(pub Vec<ClassConstructorParameter>);

#[derive(Debug)]
pub enum ClassConstructorParameter {
    Property(PropertyDeclaration),
    Field(FieldDeclaration),
}

#[derive(Debug)]
pub struct PropertyDeclaration {
    pub is_mutable: bool,
    pub identifier: Identifier,
    pub declared_type: TypeUse,
}

#[derive(Debug)]
pub struct FieldDeclaration {
    pub is_mutable: bool,
    pub identifier: Identifier,
    pub declared_type: TypeUse,
}

// Statements

#[derive(Debug)]
pub struct BlockStatement {
    pub statements: Vec<Statement>,
    pub expression: Option<Expression>,
}

#[derive(Debug)]
pub enum Statement {
    BlockStatement(BlockStatement),
    VariableDeclarationStatement(VariableDeclarationStatement),
    AssignStatement(AssignStatement),
    CallStatement(CallStatement),
    ReturnStatement(ReturnStatement),
    IfStatement(IfStatement),
    IfElseStatement(IfElseStatement),
    WhileStatement(WhileStatement),
    ForStatement(ForStatement),
}

#[derive(Debug)]
pub struct VariableDeclarationStatement {
    is_mutable: bool,
    identifier: Identifier,
    declared_type: Option<TypeUse>,
    initializer: Option<Expression>,
}

#[derive(Debug)]
pub struct AssignStatement {
    pub lhs: Expression,
    pub rhs: Expression,
}

#[derive(Debug)]
pub struct CallStatement {
    pub callee: Expression,
    pub arguments: CallArguments
}

#[derive(Debug)]
pub struct ReturnStatement(pub Option<Expression>);

#[derive(Debug)]
pub struct IfStatement {
    pub condition: Expression,
    pub then_block: BlockStatement,
}

#[derive(Debug)]
pub struct IfElseStatement {
    pub condition: Expression,
    pub then_block: BlockStatement,
    pub else_ifs: ElseIfs,
    pub else_block: BlockStatement,
}

#[derive(Debug)]
pub struct ElseIfs(pub Vec<IfStatement>);

#[derive(Debug)]
pub struct WhileStatement {
    pub condition: Expression,
    pub body: BlockStatement,
}

#[derive(Debug)]
pub struct ForStatement {
    pub variable: Identifier,
    pub iterator: Expression,
    pub body: BlockStatement,
}

// Expressions

#[derive(Debug)]
pub enum Expression {
    Ternary(TernaryExpression),
    Binary(BinaryExpression),
    Unary(UnaryExpression),
    Call(CallExpression),
    FullyQualifiedName(FullyQualifiedName),
    Closure(Closure),
    ObjectAccess(ObjectAccess),
    Literal(Literal),
}

#[derive(Debug)]
pub struct TernaryExpression {
    pub condition: Box<Expression>,
    pub true_block: Box<Expression>,
    pub false_block: Box<Expression>,
}

#[derive(Debug)]
pub struct BinaryExpression {
    pub left: Box<Expression>,
    pub operator: BinaryOperator,
    pub right: Box<Expression>,
}

#[derive(Debug)]
pub struct UnaryExpression {
    pub lhs_operators: Vec<PrefixUnaryOperator>,
    pub expression: Box<Expression>,
    pub rhs_operators: Vec<SuffixUnaryOperator>,
}

#[derive(Debug)]
pub struct CallExpression {
    pub callee: Box<Expression>,
    pub arguments: CallArguments,
}

#[derive(Debug)]
pub struct CallArguments(pub Vec<CallArgument>);

#[derive(Debug)]
pub struct CallArgument(pub Box<Expression>);

#[derive(Debug)]
pub struct Closure {
    
}

#[derive(Debug)]
pub struct ObjectAccess {
    pub receiver: Box<Expression>,
    pub navigations: ObjectNavigations
}

#[derive(Debug)]
pub struct ObjectNavigations(pub Vec<ObjectNavigation>);

#[derive(Debug)]
pub enum ObjectNavigation {
    Index(Box<Expression>),
    Identifier(Box<Identifier>)
}

#[derive(Debug)]
pub enum Literal {
    IntegerLiteral(i32),
    LongLiteral(i64),
    DoubleLiteral(f64),
    USizeLiteral(usize),
    StringLiteral(String),
    BooleanLiteral(bool),
}