use std::error::Error;

use doughlang::{
    ast::{
        types::{Literal, Path},
        visit::{Visit, Walk},
        *,
    },
    intern::interned::Interned,
    lexer::Lexer,
    parser::{Parser, expr::Prec},
};

use repline::prebaked::{Response, read_and};

fn main() -> Result<(), Box<dyn Error>> {
    read_and("\x1b[34m", "l>", " >", |line| {
        let ast: Anno<Expr> = Parser::new(Lexer::new(line)).parse(Prec::MIN)?;
        let mut to_lisp = ToLisp;
        let _ = to_lisp.visit(&ast);
        println!();
        Ok(Response::Accept)
    })?;

    Ok(())
}

#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
struct ToLisp;

impl ToLisp {
    fn bind_op(&self, op: BindOp) -> &'static str {
        match op {
            BindOp::Let => "let",
            BindOp::Type => "type",
            BindOp::Fn => "fn",
            BindOp::Mod => "mod",
            BindOp::Impl => "impl",
            BindOp::Struct => "struct",
            BindOp::Enum => "enum",
            BindOp::For => "for",
            BindOp::Match => "match",
        }
    }
    fn pat_op(&self, op: PatOp) -> &'static str {
        match op {
            PatOp::Pub => "pub",
            PatOp::Mut => "mut",
            PatOp::Ref => "ref",
            PatOp::Ptr => "ptr",
            PatOp::Rest => "rest",
            PatOp::RangeEx => "range-ex",
            PatOp::RangeIn => "range-in",
            PatOp::Record => "record",
            PatOp::Tuple => "tuple",
            PatOp::Slice => "slice",
            PatOp::ArRep => "ar-rep",
            PatOp::Typed => "typed",
            PatOp::TypePrefixed => "type-prefixed",
            PatOp::Generic => "generic-in",
            PatOp::Fn => "fn",
            PatOp::Alt => "alt",
        }
    }
    fn expr_op(&self, op: Op) -> &'static str {
        match op {
            Op::Do => "do",
            Op::As => "cast",
            Op::Macro => "macro",
            Op::Block => "block",
            Op::Array => "array",
            Op::ArRep => "ar-rep",
            Op::Group => "group",
            Op::Tuple => "tuple",
            Op::Meta => "meta",
            Op::Try => "try",
            Op::Index => "index",
            Op::Call => "call",
            Op::Pub => "pub",
            Op::Loop => "loop",
            Op::Const => "const",
            Op::Static => "static",
            Op::Match => "match",
            Op::If => "if",
            Op::While => "while",
            Op::Break => "break",
            Op::Return => "return",
            Op::Continue => "continue",
            Op::Dot => "dot",
            Op::RangeEx => "range-ex",
            Op::RangeIn => "range-in",
            Op::Neg => "neg",
            Op::Not => "not",
            Op::Identity => "identity",
            Op::Refer => "refer",
            Op::Deref => "deref",
            Op::Mul => "mul",
            Op::Div => "div",
            Op::Rem => "rem",
            Op::Add => "add",
            Op::Sub => "sub",
            Op::Shl => "shl",
            Op::Shr => "shr",
            Op::And => "and",
            Op::Xor => "xor",
            Op::Or => "or",
            Op::Lt => "lt",
            Op::Leq => "leq",
            Op::Eq => "eq",
            Op::Neq => "neq",
            Op::Geq => "geq",
            Op::Gt => "gt",
            Op::LogAnd => "log-and",
            Op::LogXor => "log-xor",
            Op::LogOr => "log-or",
            Op::Set => "set",
            Op::MulSet => "mul-set",
            Op::DivSet => "div-set",
            Op::RemSet => "rem-set",
            Op::AddSet => "add-set",
            Op::SubSet => "sub-set",
            Op::ShlSet => "shl-set",
            Op::ShrSet => "shr-set",
            Op::AndSet => "and-set",
            Op::XorSet => "xor-set",
            Op::OrSet => "or-set",
        }
    }
}

impl<'a> Visit<'a, DefaultTypes> for ToLisp {
    type Error = ();

    fn visit_expr(&mut self, expr: &'a Expr) -> Result<(), Self::Error> {
        match expr {
            Expr::Omitted => print!("()"),
            Expr::Id(path) => self.visit_path(path)?,
            Expr::MetId(id) => print!("`{id}"),
            Expr::Lit(literal) => self.visit_literal(literal)?,
            Expr::Use(import) => import.visit_in(self)?,
            Expr::Bind(bind) => bind.visit_in(self)?,
            Expr::Make(make) => make.visit_in(self)?,
            Expr::Op(op, annos) => {
                print!("({}", self.expr_op(*op));
                for anno in annos {
                    print!(" ");
                    anno.visit_in(self)?;
                }
                print!(")");
            }
        }

        Ok(())
    }

    fn visit_macro_id(&mut self, name: &'a Interned<'static, str>) -> Result<(), Self::Error> {
        print!("{name}");
        Ok(())
    }

    fn visit_symbol(&mut self, name: &'a Interned<'static, str>) -> Result<(), Self::Error> {
        print!("{name}");
        Ok(())
    }

    fn visit_path(&mut self, path: &'a Path) -> Result<(), Self::Error> {
        let Path { parts } = path;
        print!("(at");
        for part in parts {
            print!(" ");
            self.visit_symbol(part)?;
        }
        print!(")");
        Ok(())
    }

    fn visit_literal(&mut self, lit: &'a Literal) -> Result<(), Self::Error> {
        print!("{lit}");
        Ok(())
    }

    fn visit_use(&mut self, item: &'a Use) -> Result<(), Self::Error> {
        match item {
            Use::Glob => print!("(use-glob)"),
            Use::Name(name) => self.visit_symbol(name)?,
            Use::Alias(name, alias) => print!("(use-alias {name} {alias})"),
            Use::Path(name, tree) => {
                print!("(use-path {name} ");
                tree.visit_in(self)?;
                print!(")");
            }
            Use::Tree(items) => {
                print!("(use-tree");
                for item in items {
                    print!(" ");
                    item.visit_in(self)?;
                }
                print!(")");
            }
        }
        Ok(())
    }

    fn visit_pat(&mut self, item: &'a Pat) -> Result<(), Self::Error> {
        match item {
            Pat::Ignore => print!("(ignore)"),
            Pat::Never => print!("(never)"),
            Pat::MetId(id) => print!("(replace {id})"),
            Pat::Name(name) => print!("{name}"),
            Pat::Value(literal) => literal.visit_in(self)?,
            Pat::Op(pat_op, pats) => {
                print!("({}", self.pat_op(*pat_op));
                for pat in pats {
                    print!(" ");
                    pat.visit_in(self)?;
                }
                print!(")");
            }
        }
        Ok(())
    }

    fn visit_bind(&mut self, item: &'a Bind) -> Result<(), Self::Error> {
        let Bind(op, generics, pattern, exprs) = item;
        print!("({} ", self.bind_op(*op));
        if !generics.is_empty() {
            print!("(for-some");
            for generic in generics {
                print!(" {generic}");
            }
            print!(") ");
        }
        pattern.visit_in(self)?;
        for expr in exprs {
            print!(" ");
            expr.visit_in(self)?;
        }
        print!(")");
        Ok(())
    }

    fn visit_make(&mut self, item: &'a Make) -> Result<(), Self::Error> {
        item.children(self)
    }

    fn visit_makearm(&mut self, item: &'a MakeArm) -> Result<(), Self::Error> {
        item.children(self)
    }
}