use eframe::egui;
use rfd::FileDialog;
use std::path::PathBuf;
use crate::engine::backtester::BacktestConfig;

pub struct BacktestPanel {
    pub initial_deposit_str: String,
    pub leverage_str: String,
    pub spread_modifier_str: String,
    pub selected_symbols: Vec<String>,
    pub new_symbol_input: String,
    pub loaded_mql5_path: Option<PathBuf>,
    pub compiler_log: String,
    pub is_running: bool,
}

impl BacktestPanel {
    pub fn new() -> Self {
        Self {
            initial_deposit_str: "10000.0".to_string(),
            leverage_str: "100.0".to_string(),
            spread_modifier_str: "0".to_string(),
            selected_symbols: vec!["EURUSD".to_string()],
            new_symbol_input: "".to_string(),
            loaded_mql5_path: None,
            compiler_log: "Ready.".to_string(),
            is_running: false,
        }
    }

    pub fn draw(&mut self, ui: &mut egui::Ui) -> Option<BacktestConfig> {
        ui.heading("⚙️ Backtest Configuration");
        ui.separator();

        // Account Settings
        ui.group(|ui| {
            ui.label("Account Settings");
            egui::Grid::new("config_grid").num_columns(2).spacing([10.0, 5.0]).show(ui, |ui| {
                ui.label("Initial Deposit ($):");
                ui.text_edit_singleline(&mut self.initial_deposit_str);
                ui.end_row();

                ui.label("Leverage (1:X):");
                ui.text_edit_singleline(&mut self.leverage_str);
                ui.end_row();

                ui.label("Spread Modifier (points):");
                ui.text_edit_singleline(&mut self.spread_modifier_str);
                ui.end_row();
            });
        });

        ui.add_space(10.0);

        // Symbol Selection
        ui.group(|ui| {
            ui.label("Symbols for Backtest");
            ui.horizontal(|ui| {
                ui.text_edit_singleline(&mut self.new_symbol_input);
                if ui.button("Add").clicked() {
                    if !self.new_symbol_input.is_empty() && !self.selected_symbols.contains(&self.new_symbol_input) {
                        self.selected_symbols.push(self.new_symbol_input.clone());
                        self.new_symbol_input.clear();
                    }
                }
            });
            
            ui.horizontal_wrapped(|ui| {
                let mut to_remove = None;
                for (i, sym) in self.selected_symbols.iter().enumerate() {
                    ui.group(|ui| {
                        ui.horizontal(|ui| {
                            ui.label(sym);
                            if ui.small_button("x").clicked() {
                                to_remove = Some(i);
                            }
                        });
                    });
                }
                if let Some(i) = to_remove {
                    self.selected_symbols.remove(i);
                }
            });
        });

        ui.add_space(10.0);

        // MQL5 File Loading
        ui.group(|ui| {
            ui.label("MQL5 Strategy Code");
            ui.horizontal(|ui| {
                if ui.button("📂 Load .mq5 File").clicked() {
                    if let Some(path) = FileDialog::new()
                        .add_filter("MQL5 Source", &["mq5"])
                        .pick_file() 
                    {
                        self.loaded_mql5_path = Some(path);
                        self.compiler_log = "File loaded. Ready to compile.".to_string();
                    }
                }
                if let Some(p) = &self.loaded_mql5_path {
                    ui.label(p.display().to_string());
                } else {
                    ui.label("No file selected.");
                }
            });
        });

        ui.add_space(10.0);

        // Start button
        ui.horizontal(|ui| {
            if self.is_running {
                ui.add_enabled(false, egui::Button::new("Running Backtest..."));
            } else {
                if ui.button("🚀 Compile & Run Backtest").clicked() {
                    if self.loaded_mql5_path.is_none() {
                        self.compiler_log = "Error: Please load an .mq5 file first.".to_string();
                        return None;
                    }
                    if self.selected_symbols.is_empty() {
                        self.compiler_log = "Error: Please add at least one symbol.".to_string();
                        return None;
                    }

                    if let (Ok(dep), Ok(lev), Ok(spr)) = (
                        self.initial_deposit_str.parse::<f64>(),
                        self.leverage_str.parse::<f64>(),
                        self.spread_modifier_str.parse::<u32>(),
                    ) {
                        self.compiler_log = "Starting compilation...".to_string();
                        self.is_running = true;
                        
                        return Some(BacktestConfig {
                            initial_deposit: dep,
                            leverage: lev,
                            spread_modifier: spr,
                        });
                    } else {
                        self.compiler_log = "Error: Invalid numeric configuration fields.".to_string();
                    }
                }
            }
        });

        ui.add_space(5.0);
        
        // Logs
        ui.group(|ui| {
            ui.set_min_height(60.0);
            ui.label(&self.compiler_log);
        });

        None
    }
}