feat: Load hard-coded savegame file (#37)

src/features/savegame/components.rs

@@ -6,7 +6,7 @@ use std::path::PathBuf;
 pub struct SavegamePath(pub PathBuf);
 
 impl SavegamePath {
-    fn get_project_path() -> Option<PathBuf> {
+    pub fn get_project_path() -> Option<PathBuf> {
         let project_dirs = ProjectDirs::from("de", "demenik", "pomomon-garden");
 
         if let Some(dirs) = project_dirs {

src/features/savegame/messages.rs

@@ -2,3 +2,6 @@ use crate::prelude::*;
 
 #[derive(Message)]
 pub struct SavegameDumpMessage;
+
+#[derive(Message)]
+pub struct SavegameLoadMessage;

src/features/savegame/mod.rs

@@ -2,7 +2,7 @@ use crate::features::phase::components::{SessionTracker, TimerSettings};
 use crate::prelude::*;
 use messages::*;
 use std::fs::File;
-use std::io::Write;
+use std::io::{Read, Write};
 
 pub mod components;
 pub mod messages;
@@ -12,8 +12,10 @@ pub struct SavegamePlugin;
 impl Plugin for SavegamePlugin {
     fn build(&self, app: &mut App) {
         app.add_message::<SavegameDumpMessage>();
+        app.add_message::<SavegameLoadMessage>();
 
         app.add_systems(Update, dump_savegame.run_if(in_state(AppState::GameScreen)));
+        app.add_systems(Update, load_savegame.run_if(in_state(AppState::GameScreen)));
     }
 }
 
@@ -30,13 +32,13 @@ struct SaveData {
 
 fn dump_savegame(
     mut messages: MessageReader<SavegameDumpMessage>,
+    save_path: Res<SavegamePath>,
     grid: Res<Grid>,
     tile_query: Query<&TileState>,
     phase: Res<CurrentPhase>,
     tracker: Res<SessionTracker>,
     settings: Res<TimerSettings>,
     pom_query: Query<&GridPosition, With<Pom>>,
-    save_path: Res<SavegamePath>,
 ) {
     for _ in messages.read() {
         let mut tile_states = Vec::new();
@@ -87,3 +89,54 @@ fn dump_savegame(
         }
     }
 }
+
+fn load_savegame(
+    mut messages: MessageReader<SavegameLoadMessage>,
+    save_path: Res<SavegamePath>,
+    grid: Res<Grid>,
+    mut tile_query: Query<&mut TileState>,
+    mut phase: ResMut<CurrentPhase>,
+    mut tracker: ResMut<SessionTracker>,
+    mut settings: ResMut<TimerSettings>,
+    mut pom_query: Query<&mut GridPosition, With<Pom>>,
+) {
+    for _ in messages.read() {
+        if let Ok(mut file) = File::open(&save_path.0) {
+            let mut content = String::new();
+            if let Err(e) = file.read_to_string(&mut content) {
+                eprintln!("Failed to read save file: {}", e);
+                continue;
+            }
+
+            match serde_json::from_str::<SaveData>(&content) {
+                Ok(save_data) => {
+                    *phase = save_data.current_phase;
+                    *tracker = save_data.session_tracker;
+                    *settings = save_data.timer_settings;
+
+                    if let Ok(mut pom_pos) = pom_query.single_mut() {
+                        *pom_pos = save_data.pom_position;
+                    }
+
+                    for x in 0..save_data.grid_width {
+                        for y in 0..save_data.grid_height {
+                            if x < grid.width && y < grid.height {
+                                if let Ok(entity) = grid.get_tile((x, y)) {
+                                    if let Ok(mut state) = tile_query.get_mut(entity) {
+                                        *state = save_data.tiles[x as usize][y as usize];
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    println!("Game loaded from {}", save_path.0.display());
+                }
+                Err(e) => {
+                    eprintln!("Failed to parse save data: {}", e);
+                }
+            }
+        } else {
+            eprintln!("Failed to open save file at {}", save_path.0.display());
+        }
+    }
+}

src/features/start_screen/mod.rs

@@ -1,4 +1,4 @@
-use crate::prelude::*;
+use crate::{features::savegame::messages::SavegameLoadMessage, prelude::*};
 
 pub struct StartScreenPlugin;
 
@@ -120,6 +120,7 @@ fn menu(
         (&Interaction, &ButtonType, &mut BackgroundColor),
         (Changed<Interaction>, With<Button>),
     >,
+    mut load_messages: MessageWriter<SavegameLoadMessage>,
 ) {
     for (interaction, button_type, mut color) in &mut interaction_query {
         match *interaction {
@@ -127,6 +128,11 @@ fn menu(
                 *color = PRESSED_BUTTON.into();
 
                 match button_type {
+                    ButtonType::LoadGame => {
+                        commands.insert_resource(SavegamePath::new("savegame.json"));
+                        next_state.set(AppState::GameScreen);
+                        load_messages.write(SavegameLoadMessage);
+                    }
                     ButtonType::NewGame => {
                         commands.insert_resource(SavegamePath::new("savegame.json"));
                         next_state.set(AppState::GameScreen);