use ratatui::{style::Modifier, text::Span};

use super::super::style::{ratatui_pty_style_from_inline, ratatui_style_from_inline};
use super::super::types::{InlineMessageKind, InlineTextStyle, InlineTheme};
use super::message::{MessageLabels, MessageLine};
use crate::config::constants::ui;

// Note: format_tool_parameters and simplify_tool_display are available in super::text_utils
// if needed for future use.

#[expect(dead_code)]
pub(crate) fn render_message_spans(
    line: &MessageLine,
    theme: &InlineTheme,
    labels: &MessageLabels,
    prefix_text_fn: impl Fn(InlineMessageKind) -> Option<String>,
    prefix_style_fn: impl Fn(&MessageLine) -> InlineTextStyle,
    text_fallback_fn: impl Fn(InlineMessageKind) -> Option<anstyle::Color>,
) -> Vec<Span<'static>> {
    let mut spans = Vec::with_capacity(line.segments.len() + 2);
    if line.kind == InlineMessageKind::Agent {
        spans.extend(agent_prefix_spans(line, theme, labels, &prefix_style_fn));
    } else if let Some(prefix) = prefix_text_fn(line.kind) {
        let style = prefix_style_fn(line);
        spans.push(Span::styled(
            prefix,
            ratatui_style_from_inline(&style, theme.foreground),
        ));
    }

    if line.kind == InlineMessageKind::Agent {
        spans.push(Span::raw(ui::INLINE_AGENT_MESSAGE_LEFT_PADDING));
    }

    if line.segments.is_empty() {
        if spans.is_empty() {
            spans.push(Span::raw(""));
        }
        return spans;
    }

    if line.kind == InlineMessageKind::Tool {
        let tool_spans = render_tool_segments(line, theme);
        if tool_spans.is_empty() {
            spans.push(Span::raw(""));
        } else {
            spans.extend(tool_spans);
        }
        return spans;
    }

    if line.kind == InlineMessageKind::Pty {
        // Render PTY content with a subdued foreground color instead of the
        // terminal DIM modifier, which can be too faint on many terminals.
        // Segments that carry their own ANSI color keep it; uncolored segments
        // use the configured PTY fallback chain from session styling.
        let pty_fallback = text_fallback_fn(InlineMessageKind::Pty).or(theme.foreground);
        for segment in &line.segments {
            let style = ratatui_pty_style_from_inline(&segment.style, pty_fallback);
            spans.push(Span::styled(segment.text.clone(), style));
        }
        if !spans.is_empty() {
            return spans;
        }
    }

    let fallback = text_fallback_fn(line.kind).or(theme.foreground);
    for segment in &line.segments {
        let mut style = ratatui_style_from_inline(&segment.style, fallback);
        if line.kind == InlineMessageKind::User {
            style = style.add_modifier(Modifier::BOLD);
        }
        spans.push(Span::styled(segment.text.clone(), style));
    }

    if spans.is_empty() {
        spans.push(Span::raw(""));
    }

    spans
}

#[expect(dead_code)]
pub(crate) fn agent_prefix_spans(
    line: &MessageLine,
    theme: &InlineTheme,
    labels: &MessageLabels,
    prefix_style_fn: &impl Fn(&MessageLine) -> InlineTextStyle,
) -> Vec<Span<'static>> {
    let mut spans = Vec::with_capacity(3);
    let prefix_style = ratatui_style_from_inline(&prefix_style_fn(line), theme.foreground);
    let has_label = labels.agent.as_ref().is_some_and(|label| !label.is_empty());
    let prefix_has_trailing_space = ui::INLINE_AGENT_QUOTE_PREFIX
        .chars()
        .last()
        .is_some_and(|ch| ch.is_whitespace());
    if !ui::INLINE_AGENT_QUOTE_PREFIX.is_empty() {
        spans.push(Span::styled(ui::INLINE_AGENT_QUOTE_PREFIX, prefix_style));
        if has_label && !prefix_has_trailing_space {
            spans.push(Span::styled(" ", prefix_style));
        }
    }

    if let Some(label) = &labels.agent
        && !label.is_empty()
    {
        spans.push(Span::styled(label.clone(), prefix_style));
    }

    spans
}

#[expect(dead_code)]
pub(crate) fn render_tool_segments(line: &MessageLine, theme: &InlineTheme) -> Vec<Span<'static>> {
    // Render tool output without header decorations - just display segments directly
    let mut spans = Vec::with_capacity(line.segments.len());
    for segment in &line.segments {
        let style = ratatui_style_from_inline(&segment.style, theme.foreground);
        spans.push(Span::styled(segment.text.clone(), style));
    }
    spans
}

#[expect(dead_code)]
fn render_styled_action_text(
    spans: &mut Vec<Span<'static>>,
    action: &str,
    body_style: &InlineTextStyle,
    theme: &InlineTheme,
) {
    // Iterate directly without collecting to Vec
    for (i, word) in action.split_whitespace().enumerate() {
        if i > 0 {
            spans.push(Span::raw(" "));
        }

        spans.push(Span::styled(
            word.to_owned(),
            ratatui_style_from_inline(body_style, theme.foreground),
        ));
    }
}

#[expect(dead_code)]
fn strip_tool_status_prefix(text: &str) -> &str {
    let trimmed = text.trim_start();
    const STATUS_ICONS: [&str; 4] = ["✓", "✗", "~", "✕"];
    for icon in STATUS_ICONS {
        if let Some(rest) = trimmed.strip_prefix(icon) {
            return rest.trim_start();
        }
    }
    text
}
