//! Console panel for displaying output and error messages
//!
//! Shows a scrollable log of messages with color coding and a REPL input.

use eframe::egui;
use egui_extras::{Size, StripBuilder};

use crate::gui::state::{GuiState, MessageKind};
use crate::repl::{MetaCommand, ListTarget, ExecuteResult};

/// Console panel for output messages and REPL input
pub struct ConsolePanel {
    /// Whether to auto-scroll to bottom
    auto_scroll: bool,
    /// REPL input buffer
    input: String,
    /// Command history
    history: Vec<String>,
    /// Current position in history (for up/down navigation)
    history_pos: Option<usize>,
}

impl ConsolePanel {
    pub fn new() -> Self {
        Self {
            auto_scroll: true,
            input: String::new(),
            history: Vec::new(),
            history_pos: None,
        }
    }

    pub fn show(&mut self, ui: &mut egui::Ui, state: &mut GuiState) {
        StripBuilder::new(ui)
            .size(Size::exact(28.0))
            .size(Size::remainder().at_least(80.0))
            .size(Size::exact(28.0))
            .vertical(|mut strip| {
                strip.cell(|ui| {
                    ui.horizontal(|ui| {
                        ui.heading("Console");

                        ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                            if ui
                                .add_sized([64.0, 22.0], egui::Button::new("Clear"))
                                .clicked()
                            {
                                state.clear_console();
                            }

                            ui.add_sized(
                                [112.0, 22.0],
                                egui::Checkbox::new(&mut self.auto_scroll, "Auto-scroll"),
                            );

                            ui.add_sized(
                                [96.0, 22.0],
                                egui::Label::new(format!("{} messages", state.console_messages.len())),
                            );
                        });
                    });
                });

                strip.cell(|ui| {
                    egui::Frame::default()
                        .inner_margin(egui::Margin::same(4))
                        .show(ui, |ui| {
                            egui::ScrollArea::vertical()
                                .auto_shrink([false, false])
                                .stick_to_bottom(self.auto_scroll)
                                .show(ui, |ui| {
                                    if state.console_messages.is_empty() {
                                        ui.label("Type commands below (e.g., :help, :list, or geolog code)");
                                    } else {
                                        for message in &state.console_messages {
                                            let color = match message.kind {
                                                MessageKind::Info => egui::Color32::LIGHT_GRAY,
                                                MessageKind::Success => egui::Color32::from_rgb(100, 200, 100),
                                                MessageKind::Error => egui::Color32::from_rgb(255, 100, 100),
                                                MessageKind::Warning => egui::Color32::from_rgb(255, 200, 100),
                                            };

                                            let prefix = match message.kind {
                                                MessageKind::Info => ">",
                                                MessageKind::Success => "+",
                                                MessageKind::Error => "!",
                                                MessageKind::Warning => "?",
                                            };

                                            ui.horizontal(|ui| {
                                                ui.add_sized(
                                                    [12.0, 18.0],
                                                    egui::Label::new(
                                                        egui::RichText::new(prefix)
                                                            .color(color)
                                                            .monospace(),
                                                    ),
                                                );
                                                ui.label(
                                                    egui::RichText::new(&message.text)
                                                        .color(color)
                                                        .monospace(),
                                                );
                                            });
                                        }
                                    }
                                });
                        });
                });

                strip.cell(|ui| {
                    ui.horizontal(|ui| {
                        ui.add_sized(
                            [68.0, 22.0],
                            egui::Label::new(
                                egui::RichText::new("geolog>")
                                    .monospace()
                                    .color(egui::Color32::from_rgb(100, 150, 255)),
                            ),
                        );

                        let run_width = 56.0;
                        let spacing = ui.spacing().item_spacing.x;
                        let input_width = (ui.available_width() - run_width - spacing).max(120.0);
                        let response = ui.add_sized(
                            [input_width, 22.0],
                            egui::TextEdit::singleline(&mut self.input)
                                .font(egui::FontId::monospace(13.0))
                                .hint_text(":help for commands"),
                        );

                        if response.lost_focus() && ui.input(|i| i.key_pressed(egui::Key::Enter)) {
                            self.execute_input(state);
                            response.request_focus();
                        }

                        if response.has_focus() {
                            if ui.input(|i| i.key_pressed(egui::Key::ArrowUp)) {
                                self.history_up();
                            }
                            if ui.input(|i| i.key_pressed(egui::Key::ArrowDown)) {
                                self.history_down();
                            }
                        }

                        if ui
                            .add_sized([run_width, 22.0], egui::Button::new("Run"))
                            .clicked()
                        {
                            self.execute_input(state);
                        }
                    });
                });
            });
    }

    fn execute_input(&mut self, state: &mut GuiState) {
        let input = self.input.trim().to_string();
        if input.is_empty() {
            return;
        }

        // Add to history
        self.history.push(input.clone());
        self.history_pos = None;

        // Echo the input
        state.log_info(format!("geolog> {}", input));

        // Process the input
        if input.starts_with(':') {
            // Meta command
            let cmd = MetaCommand::parse(&input);
            self.handle_meta_command(state, cmd);
        } else {
            // Geolog code
            match state.repl.execute_geolog(&input) {
                Ok(results) => {
                    for result in results {
                        match result {
                            ExecuteResult::Namespace(name) => {
                                state.log_info(format!("Namespace: {}", name));
                            }
                            ExecuteResult::Theory {
                                name,
                                num_sorts,
                                num_functions,
                                num_relations,
                                num_axioms,
                            } => {
                                let mut parts = vec![format!("{} sorts", num_sorts)];
                                if num_functions > 0 {
                                    parts.push(format!("{} functions", num_functions));
                                }
                                if num_relations > 0 {
                                    parts.push(format!("{} relations", num_relations));
                                }
                                if num_axioms > 0 {
                                    parts.push(format!("{} axioms", num_axioms));
                                }
                                state.log_success(format!(
                                    "Defined theory {} ({})",
                                    name,
                                    parts.join(", ")
                                ));
                            }
                            ExecuteResult::Instance {
                                name,
                                theory_name,
                                num_elements,
                            } => {
                                state.log_success(format!(
                                    "Defined instance {} : {} ({} elements)",
                                    name, theory_name, num_elements
                                ));
                            }
                            ExecuteResult::Query(_) => {
                                state.log_info("Query executed");
                            }
                        }
                    }
                }
                Err(e) => {
                    state.log_error(e);
                }
            }
        }

        self.input.clear();
    }

    fn handle_meta_command(&mut self, state: &mut GuiState, cmd: MetaCommand) {
        match cmd {
            MetaCommand::Help(topic) => {
                match topic.as_deref() {
                    None => {
                        state.log_info("Commands:");
                        state.log_info("  :help          Show this help");
                        state.log_info("  :list          List theories and instances");
                        state.log_info("  :inspect <n>   Inspect a theory or instance");
                        state.log_info("  :chase <inst>  Run chase on instance");
                        state.log_info("  :reset         Reset all state");
                        state.log_info("  :clear         Clear console");
                        state.log_info("");
                        state.log_info("Or type geolog code directly.");
                    }
                    Some(t) => {
                        state.log_info(format!("Help topic: {}", t));
                    }
                }
            }
            MetaCommand::List(target) => {
                match target {
                    ListTarget::Theories | ListTarget::All => {
                        let theories = state.repl.list_theories();
                        if theories.is_empty() {
                            state.log_info("No theories defined.");
                        } else {
                            state.log_info("Theories:");
                            for t in theories {
                                state.log_info(format!(
                                    "  {} ({} sorts, {} rels, {} axioms)",
                                    t.name, t.num_sorts, t.num_relations, t.num_axioms
                                ));
                            }
                        }
                    }
                    ListTarget::Instances => {}
                }
                match target {
                    ListTarget::Instances | ListTarget::All => {
                        let instances = state.repl.list_instances();
                        if instances.is_empty() {
                            state.log_info("No instances defined.");
                        } else {
                            state.log_info("Instances:");
                            for i in instances {
                                state.log_info(format!(
                                    "  {} : {} ({} elements)",
                                    i.name, i.theory_name, i.num_elements
                                ));
                            }
                        }
                    }
                    ListTarget::Theories => {}
                }
            }
            MetaCommand::Inspect(name) => {
                use crate::repl::{InspectResult, format_theory_detail, format_instance_detail};
                match state.repl.inspect(&name) {
                    Some(InspectResult::Theory(detail)) => {
                        for line in format_theory_detail(&detail).lines() {
                            state.log_info(line.to_string());
                        }
                    }
                    Some(InspectResult::Instance(detail)) => {
                        for line in format_instance_detail(&detail).lines() {
                            state.log_info(line.to_string());
                        }
                    }
                    None => {
                        state.log_error(format!("Not found: {}", name));
                    }
                }
            }
            MetaCommand::Clear => {
                state.clear_console();
            }
            MetaCommand::Reset => {
                state.repl.reset();
                state.selected_item = None;
                state.log_success("State reset.");
            }
            MetaCommand::Chase { instance, max_iterations } => {
                self.run_chase(state, &instance, max_iterations);
            }
            MetaCommand::Source(path) => {
                match std::fs::read_to_string(&path) {
                    Ok(content) => {
                        state.editor_content = content;
                        state.current_file = Some(path.clone());
                        state.log_info(format!("Loaded: {}", path.display()));
                        state.execute_editor();
                    }
                    Err(e) => {
                        state.log_error(format!("Failed to load: {}", e));
                    }
                }
            }
            _ => {
                state.log_warning("Command not yet implemented in GUI");
            }
        }
    }

    fn run_chase(&self, state: &mut GuiState, instance_name: &str, max_iterations: Option<usize>) {
        use crate::core::RelationStorage;
        use crate::query::chase::chase_fixpoint;

        let theory_name = match state.repl.instances.get(instance_name) {
            Some(e) => e.theory_name.clone(),
            None => {
                state.log_error(format!("Instance '{}' not found", instance_name));
                return;
            }
        };

        let theory = match state.repl.theories.get(&theory_name) {
            Some(t) => t.clone(),
            None => {
                state.log_error(format!("Theory '{}' not found", theory_name));
                return;
            }
        };

        let sig = &theory.theory.signature;
        let axioms = &theory.theory.axioms;

        if axioms.is_empty() {
            state.log_warning(format!("Theory '{}' has no axioms", theory_name));
            return;
        }

        state.log_info(format!("Running chase on '{}' ({} axioms)...", instance_name, axioms.len()));

        let entry = state.repl.instances.get_mut(instance_name).unwrap();
        let max_iter = max_iterations.unwrap_or(100);

        let start = std::time::Instant::now();
        let result = chase_fixpoint(
            axioms,
            &mut entry.structure,
            &mut state.repl.store.universe,
            sig,
            max_iter,
        );

        match result {
            Ok(iterations) => {
                let elapsed = start.elapsed();
                // Capture structure info before releasing the borrow
                let total_tuples: usize = entry.structure.relations.iter().map(|r| r.len()).sum();
                let num_elements = entry.structure.len();

                state.log_success(format!(
                    "Chase completed in {} iterations ({:.2}ms)",
                    iterations,
                    elapsed.as_secs_f64() * 1000.0
                ));
                state.log_info(format!(
                    "Structure: {} elements, {} relation tuples",
                    num_elements,
                    total_tuples
                ));
            }
            Err(e) => {
                state.log_error(format!("Chase error: {}", e));
            }
        }
    }

    fn history_up(&mut self) {
        if self.history.is_empty() {
            return;
        }
        match self.history_pos {
            None => {
                self.history_pos = Some(self.history.len() - 1);
            }
            Some(pos) if pos > 0 => {
                self.history_pos = Some(pos - 1);
            }
            _ => {}
        }
        if let Some(pos) = self.history_pos {
            self.input = self.history[pos].clone();
        }
    }

    fn history_down(&mut self) {
        match self.history_pos {
            Some(pos) if pos + 1 < self.history.len() => {
                self.history_pos = Some(pos + 1);
                self.input = self.history[pos + 1].clone();
            }
            Some(_) => {
                self.history_pos = None;
                self.input.clear();
            }
            None => {}
        }
    }
}

impl Default for ConsolePanel {
    fn default() -> Self {
        Self::new()
    }
}