luars 0.17.0

mod lexer_config;
mod lua_language_level;
mod lua_operator_kind;
mod lua_token_data;
mod lua_token_kind;
mod lua_tokenize;
mod reader;
mod text_range;
mod tokenize_config;

pub use crate::compiler::parser::{
    lexer_config::ParserConfig, lua_language_level::LuaLanguageLevel, lua_operator_kind::*,
    lua_token_data::LuaTokenData, lua_token_kind::LuaTokenKind, lua_tokenize::LuaTokenize,
    reader::Reader, text_range::SourceRange, tokenize_config::TokensizeConfig,
};

pub struct LuaLexer<'a> {
    text: &'a str,
    tokens: Vec<LuaTokenData>,
    token_index: usize,
    current_token: LuaTokenKind,
    pub parse_config: ParserConfig,
    pub line: usize,          // current line number (linenumber in Lua)
    pub lastline: usize,      // line of last token consumed (lastline in Lua)
    pub nesting_level: usize, // parser nesting depth (like C Lua's nCcalls during compilation)
}

impl<'a> LuaLexer<'a> {
    pub fn new(text: &'a str, tokens: Vec<LuaTokenData>, level: LuaLanguageLevel) -> LuaLexer<'a> {
        let config = ParserConfig::new(level);

        let mut parser = LuaLexer {
            text,
            tokens,
            token_index: 0,
            current_token: LuaTokenKind::None,
            parse_config: config,
            line: 1,
            lastline: 1, // Initialize lastline to 1 (llex.c:176)
            nesting_level: 0,
        };

        parser.init();
        parser
    }

    fn init(&mut self) {
        if self.tokens.is_empty() {
            self.current_token = LuaTokenKind::TkEof;
        } else {
            // Initialize line from first token
            self.line = self.tokens[0].line;
            self.lastline = 1; // lastline starts at 1
            self.current_token = self.tokens[0].kind;
        }

        if is_trivia_kind(self.current_token) {
            self.bump();
        }
    }

    pub fn origin_text(&self) -> &'a str {
        self.text
    }

    pub fn current_token(&self) -> LuaTokenKind {
        self.current_token
    }

    pub fn current_token_index(&self) -> usize {
        self.token_index
    }

    pub fn current_token_range(&self) -> SourceRange {
        if self.token_index >= self.tokens.len() {
            if self.tokens.is_empty() {
                return SourceRange::EMPTY;
            } else {
                return self.tokens[self.tokens.len() - 1].range;
            }
        }

        self.tokens[self.token_index].range
    }

    pub fn previous_token_range(&self) -> SourceRange {
        if self.token_index == 0 || self.tokens.is_empty() {
            return SourceRange::EMPTY;
        }

        // Find the previous non-trivia token
        let mut prev_index = self.token_index - 1;
        while prev_index > 0 && is_trivia_kind(self.tokens[prev_index].kind) {
            prev_index -= 1;
        }

        // If we found a non-trivia token or reached the first token
        if prev_index < self.tokens.len() && !is_trivia_kind(self.tokens[prev_index].kind) {
            self.tokens[prev_index].range
        } else if prev_index == 0 {
            // If the first token is also trivia, return its range anyway
            self.tokens[0].range
        } else {
            SourceRange::EMPTY
        }
    }

    pub fn current_token_text(&self) -> &str {
        if self.current_token == LuaTokenKind::TkEof {
            return "<eof>";
        }
        if self.token_index < self.tokens.len() {
            let range = &self.tokens[self.token_index].range;
            &self.text[range.start_offset..range.end_offset()]
        } else {
            "<eof>"
        }
    }

    pub fn set_current_token_kind(&mut self, kind: LuaTokenKind) {
        if self.token_index < self.tokens.len() {
            self.tokens[self.token_index].kind = kind;
            self.current_token = kind;
        }
    }

    pub fn bump(&mut self) {
        // Port of luaX_next from llex.c:565-573
        // Save current line before consuming next token
        self.lastline = self.line;

        let mut next_index = self.token_index + 1;
        // Skip trivia tokens to find next real token
        self.skip_trivia(&mut next_index);
        self.token_index = next_index;

        if self.token_index >= self.tokens.len() {
            self.current_token = LuaTokenKind::TkEof;
            return;
        }

        // CRITICAL FIX: Update line from token's ending line number
        // This ensures multi-line tokens (long strings, multi-line comments)
        // correctly update linenumber (matches Lua C's behavior in llex)
        self.line = self.tokens[self.token_index].line;
        self.current_token = self.tokens[self.token_index].kind;
    }

    pub fn peek_next_token(&self) -> LuaTokenKind {
        let mut next_index = self.token_index + 1;
        self.skip_trivia(&mut next_index);

        if next_index >= self.tokens.len() {
            LuaTokenKind::None
        } else {
            self.tokens[next_index].kind
        }
    }

    fn skip_trivia(&self, index: &mut usize) {
        if index >= &mut self.tokens.len() {
            return;
        }

        let mut kind = self.tokens[*index].kind;
        while is_trivia_kind(kind) {
            *index += 1;
            if *index >= self.tokens.len() {
                break;
            }
            kind = self.tokens[*index].kind;
        }
    }
}

fn is_trivia_kind(kind: LuaTokenKind) -> bool {
    matches!(
        kind,
        LuaTokenKind::TkShortComment
            | LuaTokenKind::TkLongComment
            | LuaTokenKind::TkEndOfLine
            | LuaTokenKind::TkWhitespace
            | LuaTokenKind::TkShebang
    )
}