// context_screen.rs — F2 context/debug overlay
//
// Full-screen overlay showing model info, context window breakdown,
// and runtime state. Uses SectionTree for the expand/collapse tree.

use ratatui::{
    layout::Rect,
    style::{Color, Style},
    text::Line,
    Frame,
};

use super::{App, ScreenView, screen_legend};
use super::widgets::{SectionTree, pane_block, render_scrollable, tree_legend};

pub(crate) struct ConsciousScreen {
    agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>,
    tree: SectionTree,
}

impl ConsciousScreen {
    pub fn new(agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>) -> Self {
        Self { agent, tree: SectionTree::new() }
    }

    fn read_context_sections(&self) -> Vec<crate::agent::context::ContextSection> {
        use crate::agent::context::{ContextSection, ContextEntry, ConversationEntry};
        use crate::agent::api::Message;

        let ag = match self.agent.try_lock() {
            Ok(ag) => ag,
            Err(_) => return Vec::new(),
        };

        let mut sections: Vec<ContextSection> = ag.context_sections()
            .iter().map(|s| (*s).clone()).collect();

        // Build a synthetic "Memory nodes" section from conversation entries
        let mut mem_section = ContextSection::new("Memory nodes");
        let mut scored = 0usize;
        let mut unscored = 0usize;
        for ce in ag.context.conversation.entries() {
            if let ConversationEntry::Memory { key, score, .. } = &ce.entry {
                let label = match score {
                    Some(s) => { scored += 1; format!("{} (score:{:.2})", key, s) }
                    None => { unscored += 1; key.clone() }
                };
                mem_section.push(ContextEntry {
                    entry: ConversationEntry::Message(Message::user(&label)),
                    tokens: ce.tokens,
                    timestamp: ce.timestamp,
                });
            }
        }
        if !mem_section.is_empty() {
            mem_section.name = format!("Memory nodes ({} scored, {} unscored)",
                scored, unscored);
            sections.insert(sections.len() - 1, mem_section); // before conversation
        }

        sections
    }
}

impl ScreenView for ConsciousScreen {
    fn label(&self) -> &'static str { "conscious" }

    fn tick(&mut self, frame: &mut Frame, area: Rect,
            events: &[ratatui::crossterm::event::Event], app: &mut App) {
        for event in events {
            if let ratatui::crossterm::event::Event::Key(key) = event {
                if key.kind != ratatui::crossterm::event::KeyEventKind::Press { continue; }
                let context_state = self.read_context_sections();
                self.tree.handle_nav(key.code, &context_state, area.height);
            }
        }

        // Draw
        let mut lines: Vec<Line> = Vec::new();
        let section_style = Style::default().fg(Color::Yellow);

        lines.push(Line::styled("── Model ──", section_style));
        let model_display = app.context_info.as_ref()
            .map_or_else(|| app.status.model.clone(), |i| i.model.clone());
        lines.push(Line::raw(format!("  Current: {}", model_display)));
        if let Some(ref info) = app.context_info {
            lines.push(Line::raw(format!("  Backend: {}", info.backend)));
            lines.push(Line::raw(format!("  Prompt:  {}", info.prompt_file)));
            lines.push(Line::raw(format!("  Available: {}", info.available_models.join(", "))));
        }
        lines.push(Line::raw(""));

        lines.push(Line::styled("── Context State ──", section_style));
        lines.push(Line::raw(format!("  Prompt tokens: {}K", app.status.prompt_tokens / 1000)));
        if !app.status.context_budget.is_empty() {
            lines.push(Line::raw(format!("  Budget: {}", app.status.context_budget)));
        }
        let context_state = self.read_context_sections();
        if !context_state.is_empty() {
            let total: usize = context_state.iter().map(|s| s.tokens()).sum();
            lines.push(Line::raw(""));
            lines.push(Line::styled(
                "  (↑/↓ select, →/Enter expand, ← collapse, PgUp/PgDn scroll)",
                Style::default().fg(Color::DarkGray),
            ));
            lines.push(Line::raw(""));

            self.tree.render_sections(&context_state, &mut lines);

            lines.push(Line::raw(format!("  {:23} {:>6} tokens", "────────", "──────")));
            lines.push(Line::raw(format!("  {:23} {:>6} tokens", "Total", total)));
        } else if let Some(ref info) = app.context_info {
            lines.push(Line::raw(format!("  System prompt:   {:>6} chars", info.system_prompt_chars)));
            lines.push(Line::raw(format!("  Context message: {:>6} chars", info.context_message_chars)));
        }
        lines.push(Line::raw(""));

        lines.push(Line::styled("── Runtime ──", section_style));
        lines.push(Line::raw(format!(
            "  DMN: {} ({}/{})",
            app.status.dmn_state, app.status.dmn_turns, app.status.dmn_max_turns,
        )));
        lines.push(Line::raw(format!("  Reasoning: {}", app.reasoning_effort)));
        lines.push(Line::raw(format!("  Running processes: {}", app.running_processes)));
        lines.push(Line::raw(format!("  Active tools: {}", app.active_tools.lock().unwrap().len())));

        let block = pane_block("context")
            .title_top(Line::from(screen_legend()).left_aligned())
            .title_bottom(tree_legend());

        render_scrollable(frame, area, lines, block, self.tree.scroll);
    }
}