funki_lang 0.1.2

use std::collections::HashMap;
use std::fmt::{Debug, Error, Formatter};

use itertools::Itertools;

use crate::external_operators::OperatorChars;

// Parser state
pub struct ParserState {
  pub unary_ops: Vec<OperatorChars>,
  pub binary_ops: Vec<OperatorChars>,
}

impl ParserState {
  pub fn new() -> Self {
    Self {
      unary_ops: vec![],
      binary_ops: vec![],
    }
  }
}

// Template
pub struct Program {
  pub env: HashMap<String, Vec<Pattern>>,
}

// Patterns within a function
#[derive(Clone, PartialEq)]
pub struct Pattern {
  pub start: Expr,
  pub result: Expr,
  pub guards: Vec<Guard>,
}

// Guard for a function
#[derive(Clone, PartialEq)]
pub struct Guard {
  pub expr: Expr,
}

// A interpolated string is Vec<InterpolationPart>
// This represents a constituent part of an interpolation string
#[derive(Clone, PartialEq)]
pub enum InterpolationPart {
  String(String),
  Expr(Expr),
}

// The different types of expressions
#[derive(Clone, PartialEq)]
pub enum ExprInner {
  Number(i32),
  Op(Box<Expr>, Opcode, Box<Expr>),
  Unary(UnaryOp, Box<Expr>),
  CustomBinOp(Box<Expr>, OperatorChars, Box<Expr>),
  CustomUnaryOp(OperatorChars, Box<Expr>),
  FuncCall(Box<Expr>, Box<Expr>),
  Var(String),
  Tuple(Vec<Expr>),
  Str(String),
  InterpolationString(Vec<InterpolationPart>),
  Lambda(Box<Pattern>),
}

// Wrapper for expressions, includes the location of the expression in the program
#[derive(Clone, PartialEq)]
pub struct Expr {
  pub val: ExprInner,
  pub start: usize,
  pub end: usize,
}

impl Expr {
  // Constructor
  fn new(start: usize, val: ExprInner, end: usize) -> Self {
    Self { val, start, end }
  }

  // Builds a expression with a Number inner expression
  pub fn number(start: usize, v: i32, end: usize) -> Self {
    Self::new(start, ExprInner::Number(v), end)
  }

  // Builds a expression with an Op inner expression
  pub fn op(start: usize, v1: Expr, v2: Opcode, v3: Expr, end: usize) -> Self {
    Self::new(start, ExprInner::Op(Box::new(v1), v2, Box::new(v3)), end)
  }

  // Builds a expression with a Unary inner expression
  pub fn unary(start: usize, v1: UnaryOp, v2: Expr, end: usize) -> Self {
    Self::new(start, ExprInner::Unary(v1, Box::new(v2)), end)
  }

  // Builds a expression with an CustomBinOp inner expression
  pub fn custom_op(start: usize, v1: Expr, v2: OperatorChars, v3: Expr, end: usize) -> Self {
    Self::new(
      start,
      ExprInner::CustomBinOp(Box::new(v1), v2, Box::new(v3)),
      end,
    )
  }

  // Builds a expression with a Unary inner expression
  pub fn custom_unary(start: usize, v1: OperatorChars, v2: Expr, end: usize) -> Self {
    Self::new(start, ExprInner::CustomUnaryOp(v1, Box::new(v2)), end)
  }

  // Builds a expression with a function call inner expression
  pub fn func_call(start: usize, v1: Expr, v2: Expr, end: usize) -> Self {
    Self::new(start, ExprInner::FuncCall(Box::new(v1), Box::new(v2)), end)
  }

  // Builds a expression with a Var inner expression
  pub fn var(start: usize, v1: String, end: usize) -> Self {
    Self::new(start, ExprInner::Var(v1), end)
  }

  // Builds a expression with a Tuple inner expression
  pub fn tuple(start: usize, v1: Vec<Expr>, end: usize) -> Self {
    Self::new(start, ExprInner::Tuple(v1), end)
  }

  // Builds a expression with a String inner expression
  pub fn string(start: usize, v1: String, end: usize) -> Self {
    Self::new(start, ExprInner::Str(v1), end)
  }

  // Builds a expression with an InterpolationString inner expression
  pub fn interpolation_string(start: usize, v1: Vec<InterpolationPart>, end: usize) -> Self {
    Self::new(start, ExprInner::InterpolationString(v1), end)
  }

  // Builds a expression with a Lambda inner expression
  pub fn lambda(start: usize, v1: Pattern, end: usize) -> Self {
    Self::new(start, ExprInner::Lambda(Box::new(v1)), end)
  }

  // If the expression is a tuple with a single element, returns the single element
  // Otherwise, returns itself
  pub fn unwrap_tuple(self) -> Self {
    match self {
      Expr {
        val: ExprInner::Tuple(s),
        start: l,
        end: r,
      } => {
        if s.len() == 1 {
          s.get(0).unwrap().clone()
        } else {
          Expr {
            val: ExprInner::Tuple(s),
            start: l,
            end: r,
          }
        }
      }
      _ => self,
    }
  }
}

// All the different binary operations
#[derive(Copy, Clone, PartialEq)]
pub enum Opcode {
  Mul,
  Div,
  Mod,
  Add,
  Sub,
  Eq,
  Leq,
  Lt,
  Geq,
  Gt,
  And,
  Or,
  Neq,
}

// All the different unary operations
#[derive(Copy, Clone, PartialEq)]
pub enum UnaryOp {
  Not,
  Neg,
}

impl Debug for Expr {
  fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error> {
    match self.val {
      ExprInner::Var(ref s) => write!(fmt, "{}", s),
      ExprInner::FuncCall(ref n, ref v) => write!(fmt, "{:?}({:?})", n, v),
      ExprInner::Number(n) => write!(fmt, "{:?}", n),
      ExprInner::Op(ref l, op, ref r) => write!(fmt, "({:?} {:?} {:?})", l, op, r),
      ExprInner::Tuple(ref l) => write!(
        fmt,
        "{{{}}}",
        l.iter()
          .map(|i| format!("{:?}", i))
          .collect::<Vec<String>>()
          .join(", ")
      ),
      ExprInner::Unary(o, ref t) => write!(fmt, "{:?}({:?})", o, t),
      ExprInner::Str(ref s) => write!(fmt, "\"{}\"", s),
      ExprInner::InterpolationString(ref s) => write!(
        fmt,
        "stringInt({})",
        s.iter()
          .map(|i| format!("{:?}", i))
          .collect::<Vec<String>>()
          .join(" + ")
      ),
      ExprInner::Lambda(ref p) => write!(fmt, "|{:?}|", p),
      ExprInner::CustomBinOp(ref l, ref o, ref r) => {
        write!(fmt, "CustomOp({:?} {} {:?})", l, o.to_string(), r)
      }
      ExprInner::CustomUnaryOp(ref o, ref r) => write!(fmt, "CustomOp({} {:?})", o.to_string(), r),
    }
  }
}

impl Debug for InterpolationPart {
  fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error> {
    use self::InterpolationPart::*;
    match self {
      String(s) => write!(fmt, "\"{}\"", s),
      Expr(e) => write!(fmt, "{:?}", e),
    }
  }
}

impl Debug for Opcode {
  fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error> {
    use self::Opcode::*;
    match *self {
      Mul => write!(fmt, "*"),
      Div => write!(fmt, "/"),
      Mod => write!(fmt, "%"),
      Add => write!(fmt, "+"),
      Sub => write!(fmt, "-"),
      Eq => write!(fmt, "=="),
      Neq => write!(fmt, "!="),
      Leq => write!(fmt, "<="),
      Lt => write!(fmt, "<"),
      Geq => write!(fmt, ">="),
      Gt => write!(fmt, ">"),
      And => write!(fmt, "&&"),
      Or => write!(fmt, "||"),
    }
  }
}

impl Debug for UnaryOp {
  fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error> {
    use self::UnaryOp::*;
    match *self {
      Not => write!(fmt, "!"),
      Neg => write!(fmt, "-"),
    }
  }
}

impl Debug for Pattern {
  fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error> {
    write!(fmt, "{:?} -> {:?}", self.start, self.result)
  }
}

impl Debug for Program {
  fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error> {
    let mut funcs: Vec<&String> = self.env.keys().into_iter().collect();
    funcs.sort();
    write!(
      fmt,
      "{}",
      funcs
        .iter()
        .map(|f| format!(
          "#{} {}",
          *f,
          self
            .env
            .get(*f)
            .unwrap()
            .iter()
            .map(|p| format!("{:?}", p))
            .join("\n")
        ))
        .collect::<Vec<String>>()
        .join("\n")
    )
  }
}