onion-frontend 0.2.1

// In diagnostics.rs

use crate::parser::ast::ASTNode;
use colored::*;
use unicode_width::UnicodeWidthStr; // 确保导入

#[derive(Clone, Copy)]
pub enum ReportSeverity {
    Error,
    Warning,
}

pub fn format_node_based_report(
    severity: ReportSeverity,
    title: &str,
    message: &str,
    node: &ASTNode,
    help_text: &str,
) -> String {
    let (title_color, primary_color) = match severity {
        ReportSeverity::Error => (Color::BrightRed, Color::BrightRed),
        ReportSeverity::Warning => (Color::Yellow, Color::Yellow),
    };

    let (start_token, end_token) = match (&node.start_token, &node.end_token) {
        (Some(s), Some(e)) => (s, e),
        (Some(s), None) => (s, s),
        _ => {
            return format!(
                "{}: {}\n{}",
                title.color(title_color).bold(),
                message,
                "Error location not available.".italic()
            );
        }
    };

    let source_str = start_token.source_code_str();
    let lines: Vec<&str> = source_str.lines().collect();

    let (start_char, end_char) = {
        let (s, _) = start_token.origin_token_span();
        let (_, e) = end_token.origin_token_span();
        (s, e)
    };

    // 直接使用原始源码字符串进行位置计算
    let (start_line_idx, start_col_char) = find_line_and_col_from_source(start_char, &source_str);
    let (end_line_idx, end_col_char) = find_line_and_col_from_source(end_char, &source_str);

    let mut report = String::new();

    report.push_str(&format!(
        "{}: {}\n --> {}:{}\n",
        title.color(title_color).bold(),
        message,
        (start_line_idx + 1).to_string().bright_cyan(),
        (start_col_char + 1).to_string().bright_cyan()
    ));

    for i in start_line_idx..=end_line_idx {
        let line_text = lines.get(i).unwrap_or(&"");

        report.push_str(&format!(
            "     |\n{:4} | {}\n     | ",
            (i + 1).to_string().bright_cyan(),
            line_text.white()
        ));

        if i == start_line_idx && i == end_line_idx {
            // --- 情况A: 单行 ---
            let display_offset = line_text
                .chars()
                .take(start_col_char)
                .collect::<String>()
                .width();
            let underline_width = if end_col_char > start_col_char {
                line_text
                    .chars()
                    .skip(start_col_char)
                    .take(end_col_char - start_col_char)
                    .collect::<String>()
                    .width()
            } else {
                1 // 至少显示一个字符宽度
            };
            report.push_str(&format!(
                "{}{}",
                " ".repeat(display_offset),
                "~".repeat(underline_width.max(1))
                    .color(primary_color)
                    .bold()
            ));
        } else if i == start_line_idx {
            // --- 情况B: 多行的第一行 ---
            let display_offset = line_text
                .chars()
                .take(start_col_char)
                .collect::<String>()
                .width();
            let underline_width = line_text.width() - display_offset;
            report.push_str(&format!(
                "{}{}",
                " ".repeat(display_offset),
                "~".repeat(underline_width.max(1))
                    .color(primary_color)
                    .bold()
            ));
        } else if i == end_line_idx {
            // --- 情况C: 多行的最后一行 ---
            let underline_width = line_text
                .chars()
                .take(end_col_char)
                .collect::<String>()
                .width();
            report.push_str(&format!(
                "{}",
                "~".repeat(underline_width.max(1))
                    .color(primary_color)
                    .bold()
            ));
        } else {
            // --- 情况D: 多行的中间行 ---
            report.push_str(&format!(
                "{}",
                "~".repeat(line_text.width()).color(primary_color).bold()
            ));
        }
        report.push('\n');
    }

    if !help_text.is_empty() {
        report.push_str(&format!("\n{}: {}", "Help".bright_green(), help_text));
    }

    report
}

/// 从原始源码字符串中根据字符索引查找行号和列号
/// 这是更准确的版本，直接使用原始源码而不是重构的文本
pub fn find_line_and_col_from_source(char_pos: usize, source: &str) -> (usize, usize) {
    let chars: Vec<char> = source.chars().collect();

    // 如果位置超出范围，返回最后位置
    if char_pos >= chars.len() {
        let line_count = source.lines().count();
        return (line_count.saturating_sub(1), 0);
    }

    // 逐字符遍历，正确处理换行符
    let mut current_line = 0;
    let mut current_col = 0;

    for (i, &ch) in chars.iter().enumerate() {
        if i == char_pos {
            return (current_line, current_col);
        }

        if ch == '\n' {
            current_line += 1;
            current_col = 0;
        } else if ch == '\r' {
            // 检查是否是 \r\n (Windows)
            if i + 1 < chars.len() && chars[i + 1] == '\n' {
                // 这是 \r\n，跳过 \r，让 \n 处理换行
                continue;
            } else {
                // 这是单独的 \r (旧Mac风格)
                current_line += 1;
                current_col = 0;
            }
        } else {
            current_col += 1;
        }
    }

    // 如果到达这里，说明 char_pos 就是最后一个字符
    (current_line, current_col)
}