pub mod eval;
pub mod lower;
pub mod tycheck;

use std::fmt;

use erg_common::config::Input;
use erg_common::error::{
    ErrorCore, ErrorDisplay, ErrorKind::*, Location, MultiErrorDisplay, SubMessage,
};
use erg_common::style::{Attribute, Color, StyledStr, StyledString, StyledStrings, Theme, THEME};
use erg_common::traits::{Locational, Stream};
use erg_common::{impl_display_and_error, impl_stream, switch_lang};

use erg_parser::error::{ParserRunnerError, ParserRunnerErrors};

pub use crate::error::eval::*;
pub use crate::error::lower::*;
pub use crate::error::tycheck::*;
use crate::hir::Expr;

/// `unreachable!(self: Context)`
#[macro_export]
macro_rules! unreachable_error {
    ($Strcs: ident, $Strc: ident, $ctx: expr) => {
        Err($Strcs::from($Strc::unreachable(
            $ctx.cfg.input.clone(),
            $crate::erg_common::fn_name!(),
            line!(),
        )))
    };
    ($Strc: ident, $ctx: expr) => {
        Err($Strc::unreachable(
            $ctx.cfg.input.clone(),
            $crate::erg_common::fn_name!(),
            line!(),
        ))
    };
}
/// `feature_error!($Strc: struct, ctx: Context, loc: Location, name: &str)`
#[macro_export]
macro_rules! feature_error {
    ($Strcs: ident, $Strc: ident, $ctx: expr, $loc: expr, $name: expr) => {
        Err($Strcs::from($Strc::feature_error(
            $ctx.cfg.input.clone(),
            $loc,
            $name,
            $ctx.caused_by(),
        )))
    };
    ($Strc: ident, $ctx: expr, $loc: expr, $name: expr) => {
        Err($Strc::feature_error(
            $ctx.cfg.input.clone(),
            $loc,
            $name,
            $ctx.caused_by(),
        ))
    };
}
#[macro_export]
macro_rules! type_feature_error {
    ($ctx: expr, $loc: expr, $name: expr) => {
        feature_error!(TyCheckErrors, TyCheckError, $ctx, $loc, $name)
    };
}

pub fn ordinal_num(n: usize) -> String {
    match n.to_string().chars().last().unwrap() {
        '1' => format!("{n}st"),
        '2' => format!("{n}nd"),
        '3' => format!("{n}rd"),
        _ => format!("{n}th"),
    }
}

/// dname is for "double under name"
pub fn binop_to_dname(op: &str) -> &str {
    match op {
        "+" => "__add__",
        "-" => "__sub__",
        "*" => "__mul__",
        "/" => "__div__",
        "//" => "__floordiv__",
        "**" => "__pow__",
        "%" => "__mod__",
        "@" => "__matmul__",
        ".." => "__rng__",
        "<.." => "__lorng__",
        "..<" => "__rorng__",
        "<..<" => "__orng__",
        "&&" | "&" | "and" => "__and__",
        "||" | "|" | "or" => "__or__",
        "^^" | "^" => "__xor__",
        "in" => "__in__",
        "notin" => "__notin__", // NOTE: this doesn't exist in Python
        "contains" => "__contains__",
        "subof" => "__subof__",
        "supof" => "__supof__",
        "is!" => "__is__!",
        "isnot!" => "__isnot__!",
        "==" => "__eq__",
        "!=" => "__ne__",
        "<" => "__lt__",
        "<=" => "__le__",
        ">" => "__gt__",
        ">=" => "__ge__",
        "<<" => "__lshift__",
        ">>" => "__rshift__",
        other => todo!("no such binary operator: {other}"),
    }
}

pub fn unaryop_to_dname(op: &str) -> &str {
    match op {
        "+" => "__pos__",
        "-" => "__neg__",
        "~" => "__invert__",
        "!" => "__mutate__",
        "..." => "__spread__",
        other => todo!("no such unary operator: {other}"),
    }
}

pub fn readable_name(name: &str) -> &str {
    match name {
        "__add__" => "`+`",
        "__sub__" => "`-`",
        "__mul__" => "`*`",
        "__div__" => "`/`",
        "__floordiv__" => "`//`",
        "__pow__" => "`**`",
        "__mod__" => "`%`",
        "__matmul__" => "`@`",
        "__rng__" => "`..`",
        "__lorng__" => "`<..`",
        "__rorng__" => "`..<`",
        "__orng__" => "`<..<`",
        "__and__" => "`and`", // TODO: `&&` if not boolean
        "__or__" => "`or`",   // TODO: `||` if not boolean
        "__in__" => "`in`",
        "__notin__" => "`notin`",
        "__contains__" => "`contains`",
        "__subof__" => "`subof`",
        "__supof__" => "`supof`",
        "__is__!" => "`is!`",
        "__isnot__!" => "`isnot!`",
        "__eq__" => "`==`",
        "__ne__" => "`!=`",
        "__lt__" => "`<`",
        "__le__" => "`<=`",
        "__gt__" => "`>`",
        "__ge__" => "`>=`",
        "__pos__" => "`+`",
        "__neg__" => "`-`",
        "__invert__" => "`~`",
        "__mutate__" => "`!`",
        "__spread__" => "`...`",
        "__lshift__" => "`<<`",
        "__rshift__" => "`>>`",
        other => other,
    }
}

#[derive(Debug, Clone)]
pub struct CompileError {
    pub core: Box<ErrorCore>, // ErrorCore is large, so box it
    pub input: Input,
    pub caused_by: String,
    pub theme: Theme,
}

impl_display_and_error!(CompileError);

impl From<ParserRunnerError> for CompileError {
    fn from(err: ParserRunnerError) -> Self {
        Self {
            core: Box::new(err.core),
            input: err.input,
            caused_by: "".to_owned(),
            theme: THEME,
        }
    }
}

impl ErrorDisplay for CompileError {
    fn core(&self) -> &ErrorCore {
        &self.core
    }
    fn input(&self) -> &Input {
        &self.input
    }
    fn caused_by(&self) -> &str {
        &self.caused_by
    }
    fn ref_inner(&self) -> Option<&Self> {
        None
    }
}

// found, error, rhs
const ERR: Color = THEME.colors.error;
// var name, lhs
const WARN: Color = THEME.colors.warning;
// expect, hint
const HINT: Color = THEME.colors.hint;
// url, accentuation
const ACCENT: Color = THEME.colors.accent;
// url and feature = pretty
const UNDERLINE: Attribute = Attribute::Underline;
#[cfg(not(feature = "pretty"))]
const ATTR: Attribute = Attribute::Bold;
#[cfg(feature = "pretty")]
const ATTR: Attribute = Attribute::Underline;

const URL: StyledStr = StyledStr::new(
    "https://github.com/erg-lang/erg",
    Some(ACCENT),
    Some(UNDERLINE),
);

impl CompileError {
    pub fn new(core: ErrorCore, input: Input, caused_by: String) -> Self {
        Self {
            core: Box::new(core),
            input,
            caused_by,
            theme: THEME,
        }
    }

    pub fn compiler_bug(
        errno: usize,
        input: Input,
        loc: Location,
        fn_name: &str,
        line: u32,
    ) -> Self {
        Self::new(
            ErrorCore::new(
                vec![SubMessage::only_loc(loc)],
                switch_lang!(
                    "japanese" => format!("これはErg compilerのバグです、開発者に報告して下さい ({URL})\n\n{fn_name}:{line}より発生"),
                    "simplified_chinese" => format!("这是Erg编译器的错误，请报告给{URL}\n\n原因来自: {fn_name}:{line}"),
                    "traditional_chinese" => format!("這是Erg編譯器的錯誤，請報告給{URL}\n\n原因來自: {fn_name}:{line}"),
                    "english" => format!("this is a bug of the Erg compiler, please report it to {URL}\n\ncaused from: {fn_name}:{line}"),
                ),
                errno,
                CompilerSystemError,
                loc,
            ),
            input,
            "".to_owned(),
        )
    }

    pub fn stack_bug(
        input: Input,
        loc: Location,
        stack_len: u32,
        block_id: usize,
        fn_name: &str,
    ) -> Self {
        Self::new(
            ErrorCore::new(
                vec![SubMessage::only_loc(loc)],
                switch_lang!(
                    "japanese" => format!("\
スタックの要素数が異常です (要素数: {stack_len}, ブロックID: {block_id})
これはコンパイラのバグです、開発者に報告して下さい ({URL})
{fn_name}より発生"),
                "simplified_chinese" => format!("\
堆栈中的元素数无效（元素数: {stack_len}，块id: {block_id}）
这是 Erg 编译器的一个错误，请报告它 ({URL})
起因于: {fn_name}"),
                "traditional_chinese" => format!("\
堆棧中的元素數無效（元素數: {stack_len}，塊id: {block_id}）\n
這是 Erg 編譯器的一個錯誤，請報告它 ({URL})
起因於: {fn_name}"),
                    "english" => format!("\
the number of elements in the stack is invalid (num of elems: {stack_len}, block id: {block_id})\n
this is a bug of the Erg compiler, please report it to {URL}
caused from: {fn_name}"),
                ),
                0,
                CompilerSystemError,
                loc,
            ),
            input,
            "".to_owned(),
        )
    }

    pub fn feature_error(input: Input, loc: Location, name: &str, caused_by: String) -> Self {
        Self::new(
            ErrorCore::new(
                vec![SubMessage::only_loc(loc)],
                switch_lang!(
                    "japanese" => format!("この機能({name})はまだ正式に提供されていません"),
                    "simplified_chinese" => format!("此功能（{name}）尚未实现"),
                    "traditional_chinese" => format!("此功能（{name}）尚未實現"),
                    "english" => format!("this feature({name}) is not implemented yet"),
                ),
                0,
                FeatureError,
                loc,
            ),
            input,
            caused_by,
        )
    }

    pub fn system_exit() -> Self {
        Self::new(
            ErrorCore::new(
                vec![SubMessage::only_loc(Location::Unknown)],
                switch_lang!(
                    "japanese" => "システムを終了します",
                    "simplified_chinese" => "系统正在退出",
                    "traditional_chinese" => "系統正在退出",
                    "english" => "system is exiting",
                ),
                0,
                SystemExit,
                Location::Unknown,
            ),
            Input::dummy(),
            "".to_owned(),
        )
    }
}

pub type EffectError = TyCheckError;
pub type EffectErrors = TyCheckErrors;

impl EffectError {
    pub fn has_effect(input: Input, errno: usize, expr: &Expr, caused_by: String) -> Self {
        Self::new(
            ErrorCore::new(
                vec![SubMessage::only_loc(expr.loc())],
                switch_lang!(
                    "japanese" => "この式には副作用があります",
                    "simplified_chinese" => "此表达式会产生副作用",
                    "traditional_chinese" => "此表達式會產生副作用",
                    "english" => "this expression causes a side-effect",
                ),
                errno,
                HasEffect,
                expr.loc(),
            ),
            input,
            caused_by,
        )
    }

    pub fn proc_assign_error(input: Input, errno: usize, loc: Location, caused_by: String) -> Self {
        let hint = Some(
            switch_lang!(
                "japanese" => {
                let mut s = StyledStrings::default();
                s.push_str("変数の末尾に");
                s.push_str_with_color_and_attr("!", WARN, ATTR);
                s.push_str("をつけてください");
                s
                },
                "simplified_chinese" => {
                let mut s = StyledStrings::default();
                s.push_str("请在变量名后加上");
                s.push_str_with_color_and_attr("!", WARN, ATTR);
                s
                },
                "traditional_chinese" => {
                let mut s = StyledStrings::default();
                s.push_str("請在變量名後加上");
                s.push_str_with_color_and_attr("!", WARN, ATTR);
                s
                },
                "english" => {

                let mut s = StyledStrings::default();
                s.push_str("add ");
                s.push_str_with_color_and_attr("!", WARN, ATTR);
                s.push_str(" to the end of the variable name");
                s
                },
            )
            .to_string(),
        );
        Self::new(
            ErrorCore::new(
                vec![SubMessage::ambiguous_new(loc, vec![], hint)],
                switch_lang!(
                    "japanese" => "プロシージャを通常の変数に代入することはできません",
                    "simplified_chinese" => "不能将过程赋值给普通变量",
                    "traditional_chinese" => "不能將過程賦值給普通變量",
                    "english" => "cannot assign a procedure to a normal variable",
                ),
                errno,
                HasEffect,
                loc,
            ),
            input,
            caused_by,
        )
    }

    pub fn touch_mut_error(input: Input, errno: usize, expr: &Expr, caused_by: String) -> Self {
        Self::new(
            ErrorCore::new(
                vec![SubMessage::only_loc(expr.loc())],
                switch_lang!(
                    "japanese" => "関数中で可変オブジェクトにアクセスすることは出来ません",
                    "simplified_chinese" => "函数中不能访问可变对象",
                    "traditional_chinese" => "函數中不能訪問可變對象",
                    "english" => "cannot access a mutable object in a function",
                ),
                errno,
                HasEffect,
                expr.loc(),
            ),
            input,
            caused_by,
        )
    }
}

pub type OwnershipError = CompileError;
pub type OwnershipErrors = CompileErrors;

impl OwnershipError {
    pub fn move_error(
        input: Input,
        errno: usize,
        name: &str,
        name_loc: Location,
        moved_loc: Location,
        caused_by: String,
    ) -> Self {
        let found = StyledString::new(name, Some(ERR), Some(ATTR));
        Self::new(
            ErrorCore::new(
                vec![SubMessage::only_loc(name_loc)],
                switch_lang!(
                    "japanese" => format!(
                        "{found}は{}行目ですでに移動されています",
                        moved_loc.ln_begin().unwrap_or(0)
                    ),
                    "simplified_chinese" => format!(
                        "{found}已移至第{}行",
                        moved_loc.ln_begin().unwrap_or(0)
                    ),
                    "traditional_chinese" => format!(
                        "{found}已移至第{}行",
                        moved_loc.ln_begin().unwrap_or(0)
                    ),
                    "english" => format!(
                        "{found} was moved in line {}",
                        moved_loc.ln_begin().unwrap_or(0)
                    ),
                ),
                errno,
                MoveError,
                name_loc,
            ),
            input,
            caused_by,
        )
    }
}

#[derive(Debug, Clone)]
pub struct CompileErrors(Vec<CompileError>);

impl std::error::Error for CompileErrors {}

impl_stream!(CompileErrors, CompileError);

impl From<ParserRunnerErrors> for CompileErrors {
    fn from(err: ParserRunnerErrors) -> Self {
        Self(err.into_iter().map(CompileError::from).collect())
    }
}

impl From<Vec<CompileError>> for CompileErrors {
    fn from(errs: Vec<CompileError>) -> Self {
        Self(errs)
    }
}

impl From<CompileError> for CompileErrors {
    fn from(err: CompileError) -> Self {
        Self(vec![err])
    }
}

impl MultiErrorDisplay<CompileError> for CompileErrors {}

impl fmt::Display for CompileErrors {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.fmt_all(f)
    }
}

impl CompileErrors {
    pub fn flush(&mut self) -> Self {
        Self(self.0.drain(..).collect())
    }
}

pub type SingleCompileResult<T> = Result<T, CompileError>;
pub type CompileResult<T> = Result<T, CompileErrors>;
pub type CompileWarning = CompileError;
pub type CompileWarnings = CompileErrors;

#[cfg(test)]
mod test {
    use crate::{
        error::*,
        hir::Identifier,
        ty::{Predicate, Type},
        varinfo::{AbsLocation, VarInfo},
    };
    use erg_common::{config::Input, error::Location};
    use erg_parser::ast::{VarName, VisModifierSpec};

    // These Erg codes are not correct grammar.
    // This test make sure sub_msg and hint are displayed correctly.
    #[test]
    fn default_error_format_confirmation() {
        let mut errors = Vec::new();

        let input = Input::pipe("stack bug error".to_owned());
        let loc = Location::Line(1);
        let err = CompileError::stack_bug(input, loc, 0, 0, "FileName");
        errors.push(err);

        let input = Input::pipe("checker bug error".to_owned());
        let errno = 0;
        let err = TyCheckError::checker_bug(input, errno, Location::Unknown, "name", 1);
        errors.push(err);

        let loc = Location::LineRange(1, 3);
        let input = Input::pipe("args\nmissing\nerror".to_string());
        let caused_by = "<caused_by>";
        let err = TyCheckError::args_missing_error(
            input,
            errno,
            loc,
            "\"Callee name here\"",
            caused_by.into(),
            vec!["sample".into(), "args".into(), "here".into()],
        );
        errors.push(err);

        let loc = Location::Range {
            ln_begin: 1,
            col_begin: 0,
            ln_end: 1,
            col_end: 17,
        };
        let expect = Type::Nat;
        let found = Type::Int;
        let input = Input::pipe("return type error".to_string());
        let name = "name";
        let err = TyCheckError::return_type_error(
            input,
            errno,
            loc,
            caused_by.to_string(),
            name,
            &expect,
            &found,
        );
        errors.push(err);

        let loc = Location::Range {
            ln_begin: 1,
            col_begin: 0,
            ln_end: 1,
            col_end: 4,
        };
        let expect = Type::Nat;
        let found = Type::Int;
        let input = Input::pipe("type mismatch error".to_string());
        let err = TyCheckError::type_mismatch_error(
            input,
            errno,
            loc,
            caused_by.into(),
            name,
            Some(1),
            &expect,
            &found,
            None,
            Some("hint message here".to_owned()),
        );
        errors.push(err);

        let input = Input::pipe(
            "too_many_args_error(some_long_name_variable_1,
    some_long_name_variable_2,
    some_long_name_variable_3,
    some_long_name_variable_4) ="
                .to_string(),
        );
        let loc = Location::LineRange(1, 4);
        let callee_name = "callee name";
        let params_len = 3;
        let pos_args_len = 4;
        let kw_args_len = 4;
        let err = TyCheckError::too_many_args_error(
            input,
            errno,
            loc,
            callee_name,
            caused_by.to_string(),
            params_len,
            pos_args_len,
            kw_args_len,
        );
        errors.push(err);

        let input = Input::pipe("argument error".to_string());
        let loc = Location::range(1, 0, 1, 8);
        let err = TyCheckError::argument_error(input, errno, loc, caused_by.to_string(), 1, 2);
        errors.push(err);

        let input = Input::pipe("Nat <: Int <: Ratio".to_string());
        let loc = Location::range(1, 0, 1, 10);
        let sub_t = &Type::Nat;
        let sup_t = &Type::Int;
        let err =
            TyCheckError::subtyping_error(input, errno, sub_t, sup_t, loc, caused_by.to_string());
        errors.push(err);

        let input = Input::pipe("pred unification error".to_string());
        let lhs = &Predicate::Const("Str".into());
        let rhs = &Predicate::Const("Nat".into());
        let err =
            TyCheckError::pred_unification_error(input, errno, lhs, rhs, caused_by.to_string());
        errors.push(err);

        let input = Input::pipe("Trait member type error".to_string());
        let errno = 0;
        let loc = Location::Range {
            ln_begin: 1,
            col_begin: 0,
            ln_end: 1,
            col_end: 5,
        };
        let t_ty = &Type::Float;
        let exp = &Type::Nat;
        let fnd = &Type::Obj;
        let err = TyCheckError::trait_member_type_error(
            input,
            errno,
            loc,
            caused_by.to_string(),
            "member name",
            t_ty,
            exp,
            fnd,
            Some("hint message here".to_string()),
        );
        errors.push(err);

        let input = Input::pipe("trait member not defined error".to_string());
        let member_name = "member name";
        let trait_type = &Type::ClassType;
        let class_type = &Type::Ellipsis;
        let hint = Some("hint message here".to_string());
        let err = TyCheckError::trait_member_not_defined_error(
            input,
            errno,
            caused_by.to_string(),
            member_name,
            trait_type,
            class_type,
            hint,
            Location::Unknown,
        );
        errors.push(err);

        let input = Input::pipe("singular no attribute error".to_string());
        let loc = Location::Range {
            ln_begin: 1,
            col_begin: 0,
            ln_end: 1,
            col_end: 8,
        };
        let obj_name = "ojb name";
        let obj_t = Type::Bool;
        let name = "name";
        let similar_name = Some("similar name");
        let err = LowerError::singular_no_attr_error(
            input,
            errno,
            loc,
            caused_by.to_string(),
            obj_name,
            &obj_t,
            name,
            similar_name,
        );
        errors.push(err);

        let input = Input::pipe("ambiguous type error".to_string());
        let raw = erg_parser::ast::Identifier::new(
            VisModifierSpec::Private,
            VarName::from_str("variable_name".into()),
        );
        let expr = Identifier::new(
            raw,
            None,
            VarInfo::new(
                Type::Nat,
                crate::varinfo::Mutability::Const,
                crate::ty::Visibility::DUMMY_PRIVATE,
                crate::varinfo::VarKind::Builtin,
                None,
                None,
                None,
                AbsLocation::unknown(),
            ),
        );
        let candidates = &[Type::Nat, Type::Inf, Type::Bool];
        let err =
            EvalError::ambiguous_type_error(input, errno, &expr, candidates, caused_by.to_string());
        errors.push(err);

        let input = Input::pipe("invalid type cast error".to_string());
        let loc = Location::range(1, 8, 1, 17);
        let cast_to = Type::Error;
        let hint = Some("hint message here".to_string());
        let err = EvalError::invalid_type_cast_error(
            input,
            errno,
            loc,
            caused_by.to_string(),
            name,
            &cast_to,
            hint,
        );
        errors.push(err);

        let input = Input::pipe("override error".to_string());
        let name_loc = Location::range(1, 0, 1, 8);
        let superclass = &Type::Failure;
        let err = TyCheckError::override_error(
            input,
            errno,
            name,
            name_loc,
            superclass,
            caused_by.to_string(),
        );
        errors.push(err);

        let input = Input::pipe("visibility error".to_string());
        let loc = Location::Line(1);
        let vis = crate::ty::Visibility::DUMMY_PRIVATE;
        let err =
            TyCheckError::visibility_error(input, errno, loc, caused_by.to_string(), name, vis);
        errors.push(err);

        let input = Input::pipe("import nunpy as np".to_string());
        let errno = 0;
        let desc = "nunpy is not defined".to_string();
        let loc = Location::range(1, 7, 1, 12);
        let similar_erg_mod = Some("numpyer".into());
        let similar_py_mod = Some("numpy".into());
        let err = TyCheckError::import_error(
            input.clone(),
            errno,
            desc.clone(),
            loc,
            caused_by.to_string(),
            similar_erg_mod.clone(),
            similar_py_mod.clone(),
        );
        errors.push(err);

        let err = TyCheckError::import_error(
            input.clone(),
            errno,
            desc.clone(),
            loc,
            caused_by.to_string(),
            None,
            similar_py_mod,
        );
        errors.push(err);

        let err = TyCheckError::import_error(
            input.clone(),
            errno,
            desc.clone(),
            loc,
            caused_by.to_string(),
            similar_erg_mod,
            None,
        );
        errors.push(err);

        let err =
            TyCheckError::import_error(input, errno, desc, loc, caused_by.to_string(), None, None);
        errors.push(err);

        for err in errors.into_iter() {
            print!("{err}");
        }
    }
}