use crate::*;


pub enum SemanticToken {
    MacroDefinition(MacroDefinition),
    BlockToken(BlockToken),
}

#[derive(Clone)]
pub struct MacroDefinition {
    pub name: Tracked<String>,
    pub arguments: Vec<Tracked<ArgumentDefinition>>,
    pub body: MacroDefinitionBody,
}

#[derive(Clone)]
pub struct ArgumentDefinition {
    pub name: String,
    pub variant: ArgumentType,
}

#[derive(Clone, Copy, Debug, PartialEq)]
pub enum ArgumentType {
    Integer,
    Block,
    List,
}

impl std::fmt::Display for ArgumentType {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
        match self {
            ArgumentType::Integer => write!(f, "an integer"),
            ArgumentType::Block => write!(f, "a block"),
            ArgumentType::List => write!(f, "a list"),
        }
    }
}

#[derive(Clone)]
pub enum MacroDefinitionBody {
    Integer(Tracked<IntegerToken>),
    Block(Vec<Tracked<BlockToken>>),
    List(Tracked<ListToken>),
    Invocation(Tracked<Invocation>),
}

#[derive(Clone)]
pub struct ConditionalBlock {
    pub predicate: Tracked<IntegerToken>,
    pub body: Tracked<BlockToken>,
}

#[derive(Clone)]
pub enum IntegerToken {
    IntegerLiteral(isize),
    Expression(Expression),
    Invocation(Invocation),
}

#[derive(Clone)]
pub struct Expression {
    pub tokens: Vec<Tracked<ExpressionToken>>,
}

#[derive(Clone)]
pub enum ExpressionToken {
    IntegerToken(Box<IntegerToken>),
    ListToken(ListToken),
    Invocation(Invocation),
    Operator(Operator),
}

#[derive(Clone)]
pub enum BlockToken {
    LabelDefinition(String),
    PinnedAddress(Tracked<IntegerToken>),
    ConditionalBlock(Box<ConditionalBlock>),
    WordTemplate(WordTemplate),
    Block(Vec<Tracked<BlockToken>>),
    Invocation(Invocation),
}

#[derive(Clone)]
pub enum ListToken {
    StringLiteral(StringLiteral),
    ListLiteral(Vec<Tracked<IntegerToken>>),
    Invocation(Invocation),
}

#[derive(Clone)]
pub struct Invocation {
    pub name: String,
    pub arguments: Vec<Tracked<InvocationArgument>>,
}

#[derive(Clone)]
pub enum InvocationArgument {
    IntegerToken(IntegerToken),
    BlockToken(BlockToken),
    ListToken(ListToken),
    Invocation(Invocation),
}


impl Expression {
    pub fn is_list(&self) -> bool {
        self.tokens.iter().all(|t| {
            match t.value {
                ExpressionToken::IntegerToken(_) => true,
                ExpressionToken::Invocation(_) => true,
                ExpressionToken::ListToken(_) => false,
                ExpressionToken::Operator(_) => false,
            }
        })
    }

    pub fn to_list(self) -> Vec<Tracked<IntegerToken>> {
        let mut list = Vec::new();
        for token in self.tokens {
            let source = token.source;
            match token.value {
                ExpressionToken::IntegerToken(token) => {
                    let tracked = Tracked::from(*token, source);
                    list.push(tracked);
                }
                ExpressionToken::Invocation(invocation) => {
                    let token = IntegerToken::Invocation(invocation);
                    list.push(Tracked::from(token, source));
                }
                ExpressionToken::ListToken(_) => unreachable!(
                    "Could not convert expression containing a list token to a list"),
                ExpressionToken::Operator(_) => unreachable!(
                    "Could not convert expression containing an operator to a list"),
            };
        }
        return list;
    }
}


pub enum SemanticError {
    MisplacedSeparator,
    MisplacedMacroDefinition,

    ExpectedInteger(SemanticLocation),
    ExpectedBlock(SemanticLocation),
    ExpectedString(SemanticLocation),

    InvalidArgumentDefinition,
    InvalidInvocationArgument,
    InvalidBlockInExpression,

    GlobalLabelInMacroDefinition,
    LocalLabelWithoutNamespace,
    LocalSymbolWithoutNamespace,
}

#[derive(Clone, Copy)]
pub enum SemanticLocation {
    MacroDefinitionBody,
    Expression,
    ConditionPredicate,
    ConditionBody,
    Program,
    BlockLiteral,
    PinAddress,
}

impl std::fmt::Display for SemanticLocation {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
        let string = match self {
            SemanticLocation::Expression =>
                "inside this expression",
            SemanticLocation::ConditionPredicate =>
                "as the predicate of this conditional block",
            SemanticLocation::ConditionBody =>
                "as the body of this conditional block",
            SemanticLocation::Program =>
                "at the outermost level of the program",
            SemanticLocation::BlockLiteral =>
                "inside this block literal",
            SemanticLocation::MacroDefinitionBody =>
                "inside the body of this macro definition",
            SemanticLocation::PinAddress =>
                "as the address of this pin",
        };
        write!(f, "{string}")
    }
}


pub fn report_semantic_errors(errors: &[Tracked<SemanticError>], source_code: &str) {
    for error in errors {
        report_semantic_error(error, source_code);
    }
}

fn report_semantic_error(error: &Tracked<SemanticError>, source_code: &str) {
    let context = Context { source_code: &source_code, source: &error.source };
    let message = match &error.value {
        SemanticError::MisplacedSeparator =>
            "Separators can only be used for constructing an argument list",
        SemanticError::MisplacedMacroDefinition =>
            "Macro definition must be placed at the outermost level of a program",

        SemanticError::ExpectedInteger(location) =>
            &format!("An integer value was expected {location}"),
        SemanticError::ExpectedBlock(location) =>
            &format!("A block value was expected {location}"),
        SemanticError::ExpectedString(location) =>
            &format!("A string value was expected {location}"),

        SemanticError::InvalidArgumentDefinition =>
            "Argument definition must take one of the following forms: name, {name}, or [name]",
        SemanticError::InvalidInvocationArgument =>
            "This token cannot be used in an invocation argument",
        SemanticError::InvalidBlockInExpression =>
            "Expression cannot contain a block token",

        SemanticError::GlobalLabelInMacroDefinition =>
            &format!("Macro definition cannot contain a global label"),
        SemanticError::LocalLabelWithoutNamespace =>
            &format!("Local label must be placed inside a macro definition or after a global label"),
        SemanticError::LocalSymbolWithoutNamespace =>
            &format!("Local symbol must be placed inside a macro definition or after a global label"),
    };

    report_source_issue(LogLevel::Error, &context, message);
}


pub fn print_semantic_token(i: usize, token: &SemanticToken) {
    match token {
        SemanticToken::MacroDefinition(definition) => {
            indent!(i, "MacroDefinition({})", definition.name);
            for argument in &definition.arguments {
                print_argument_definition(i+1, argument);
            }
            match &definition.body {
                MacroDefinitionBody::Integer(integer) => {
                    print_integer_token(i+1, integer)
                }
                MacroDefinitionBody::Block(tokens) => {
                    print_block(i+1, tokens);
                }
                MacroDefinitionBody::List(list) => {
                    print_list_token(i+1, list);
                }
                MacroDefinitionBody::Invocation(invocation) => {
                    print_invocation(i+1, invocation);
                }
            }
        }
        SemanticToken::BlockToken(block) => print_block_token(i, block),
    }
}

fn print_argument_definition(i: usize, argument: &ArgumentDefinition) {
    match argument.variant {
        ArgumentType::Integer => {
            indent!(i, "Argument({}, integer)", argument.name)
        }
        ArgumentType::Block => {
            indent!(i, "Argument({}, block)", argument.name)
        }
        ArgumentType::List => {
            indent!(i, "Argument({}, list)", argument.name)
        }
    }
}

fn print_block_token(i: usize, block: &BlockToken) {
    match block {
        BlockToken::Invocation(invocation) => {
            print_invocation(i, invocation)
        }
        BlockToken::LabelDefinition(name) => {
            indent!(i, "LabelDefinition({name})")
        }
        BlockToken::Block(block) => {
            print_block(i, block);
        }
        BlockToken::PinnedAddress(integer) => {
            indent!(i, "PinnedAddress");
            print_integer_token(i+1, integer);
        }
        BlockToken::ConditionalBlock(condition) => {
            indent!(i, "ConditionalBlock");
            indent!(i+1, "Predicate");
            print_integer_token(i+2, &condition.predicate);
            indent!(i+1, "Body");
            print_block_token(i+2, &condition.body);
        }
        BlockToken::WordTemplate(word_template) => {
            indent!(i, "WordTemplate({word_template})")
        }
    }
}

fn print_block(i: usize, tokens: &[Tracked<BlockToken>]) {
    indent!(i, "Block");
    for token in tokens {
        print_block_token(i+1, token);
    }
}

fn print_invocation(i: usize, invocation: &Invocation) {
    indent!(i, "Invocation({})", invocation.name);
    for argument in &invocation.arguments {
        print_invocation_argument(i+1, argument);
    }
}

fn print_invocation_argument(i: usize, argument: &InvocationArgument) {
    match &argument {
        InvocationArgument::ListToken(list) => {
            print_list_token(i, list)
        }
        InvocationArgument::IntegerToken(integer) => {
            print_integer_token(i, integer)
        }
        InvocationArgument::BlockToken(block) => {
            print_block_token(i, block)
        }
        InvocationArgument::Invocation(invocation) => {
            print_invocation(i, invocation)
        }
    }
}

fn print_integer_token(i: usize, integer: &IntegerToken) {
    match integer {
        IntegerToken::IntegerLiteral(value) => {
            indent!(i, "IntegerValue({value})")
        }
        IntegerToken::Expression(expression) => {
            print_expression(i, expression)
        }
        IntegerToken::Invocation(invocation) => {
            print_invocation(i, invocation)
        }
    }
}

fn print_list_token(i: usize, string: &ListToken) {
    match string {
        ListToken::StringLiteral(string_literal) => {
            indent!(i, "StringLiteral({string_literal})")
        }
        ListToken::ListLiteral(integers) => {
            indent!(i, "ListLiteral");
            for integer in integers {
                print_integer_token(i+1, integer);
            }
        }
        ListToken::Invocation(invocation) => {
            print_invocation(i, invocation)
        }
    }
}

fn print_expression(i: usize, expression: &Expression) {
    indent!(i, "Expression");
    for token in &expression.tokens {
        match &token.value {
            ExpressionToken::IntegerToken(integer) => {
                print_integer_token(i+1, &integer)
            }
            ExpressionToken::ListToken(list) => {
                print_list_token(i+1, &list)
            }
            ExpressionToken::Invocation(invocation) => {
                print_invocation(i+1, &invocation);
            }
            ExpressionToken::Operator(operator) => {
                indent!(i+1, "Operator({operator})")
            }
        }
    }
}