vtcode-core 0.9.1

use crate::ui::theme;
use crate::utils::transcript;
use anstream::{AutoStream, ColorChoice};
use anstyle::{Reset, Style};
use anstyle_query::{clicolor, clicolor_force, no_color, term_supports_color};
use anyhow::Result;
use std::io::{self, Write};

/// Styles available for rendering messages
#[derive(Clone, Copy)]
pub enum MessageStyle {
    Info,
    Error,
    Output,
    Response,
    Tool,
    User,
}

impl MessageStyle {
    fn style(self) -> Style {
        let styles = theme::active_styles();
        match self {
            Self::Info => styles.info,
            Self::Error => styles.error,
            Self::Output => styles.output,
            Self::Response => styles.response,
            Self::Tool => styles.tool,
            Self::User => styles.user,
        }
    }

    fn indent(self) -> &'static str {
        match self {
            Self::Response | Self::Tool => "  ",
            _ => "",
        }
    }
}

/// Renderer with deferred output buffering
pub struct AnsiRenderer {
    writer: AutoStream<io::Stdout>,
    buffer: String,
    color: bool,
}

impl AnsiRenderer {
    /// Create a new renderer for stdout
    pub fn stdout() -> Self {
        let color =
            clicolor_force() || (!no_color() && clicolor().unwrap_or_else(term_supports_color));
        let choice = if color {
            ColorChoice::Auto
        } else {
            ColorChoice::Never
        };
        Self {
            writer: AutoStream::new(std::io::stdout(), choice),
            buffer: String::new(),
            color,
        }
    }

    /// Push text into the buffer
    pub fn push(&mut self, text: &str) {
        self.buffer.push_str(text);
    }

    /// Flush the buffer with the given style
    pub fn flush(&mut self, style: MessageStyle) -> Result<()> {
        let style = style.style();
        if self.color {
            writeln!(self.writer, "{style}{}{Reset}", self.buffer)?;
        } else {
            writeln!(self.writer, "{}", self.buffer)?;
        }
        self.writer.flush()?;
        transcript::append(&self.buffer);
        self.buffer.clear();
        Ok(())
    }

    /// Convenience for writing a single line
    pub fn line(&mut self, style: MessageStyle, text: &str) -> Result<()> {
        let indent = style.indent();

        if text.contains('\n') {
            let trailing_newline = text.ends_with('\n');
            for line in text.lines() {
                self.buffer.clear();
                if !indent.is_empty() && !line.is_empty() {
                    self.buffer.push_str(indent);
                }
                self.buffer.push_str(line);
                self.flush(style)?;
            }
            if trailing_newline {
                self.buffer.clear();
                if !indent.is_empty() {
                    self.buffer.push_str(indent);
                }
                self.flush(style)?;
            }
            Ok(())
        } else {
            self.buffer.clear();
            if !indent.is_empty() && !text.is_empty() {
                self.buffer.push_str(indent);
            }
            self.buffer.push_str(text);
            self.flush(style)
        }
    }

    /// Write styled text without a trailing newline
    pub fn inline_with_style(&mut self, style: Style, text: &str) -> Result<()> {
        if self.color {
            write!(self.writer, "{style}{}{Reset}", text)?;
        } else {
            write!(self.writer, "{}", text)?;
        }
        self.writer.flush()?;
        Ok(())
    }

    /// Write a line with an explicit style
    pub fn line_with_style(&mut self, style: Style, text: &str) -> Result<()> {
        if self.color {
            writeln!(self.writer, "{style}{}{Reset}", text)?;
        } else {
            writeln!(self.writer, "{}", text)?;
        }
        self.writer.flush()?;
        transcript::append(text);
        Ok(())
    }

    /// Write a raw line without styling
    pub fn raw_line(&mut self, text: &str) -> Result<()> {
        writeln!(self.writer, "{}", text)?;
        self.writer.flush()?;
        transcript::append(text);
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_styles_construct() {
        let info = MessageStyle::Info.style();
        assert_eq!(info, MessageStyle::Info.style());
        let resp = MessageStyle::Response.style();
        assert_eq!(resp, MessageStyle::Response.style());
        let tool = MessageStyle::Tool.style();
        assert_eq!(tool, MessageStyle::Tool.style());
    }

    #[test]
    fn test_renderer_buffer() {
        let mut r = AnsiRenderer::stdout();
        r.push("hello");
        assert_eq!(r.buffer, "hello");
    }
}