Store all user data as CSV files.v3.0

4 files changed, 381 insertions, 240 deletions

diff --git a/README.md b/README.md
index 6167659..d0c9502 100644
--- a/README.md
+++ b/README.md
@@ -27,12 +27,14 @@ archive view and restore them.
 Ever felt like your data is being held hostage? Not anymore! Import and
 export your tasks using the widely supported CSV text file format.
 
-Want to be part of the last frontier? Grab the bleeding edge version 2
-which brings: sorting capabilities; better text input with UTF8
+Want to be part of the last frontier? Grab the new bleeding edge stuff:
+Version 2 brings sorting capabilities; better text input with UTF8
 support; possibility to archive and reset all current tasks with a
 single command; and allows to merge tasks with the same name. As an
 extra , you'll need to export and re-import your tasks due to some
-database incompatibility (oh, the joy).
+database incompatibility (oh, the joy). With version 3 all your data is
+stored in CSV format, so that you can migrate your database one last
+time (yay)!
 
 And if you don't like what you're seeing, this is your lucky day!
 Because you have access to the source code, you can adapt it to your
diff --git a/modules/README.md b/modules/README.md
index d9b5839..13179e6 100644
--- a/modules/README.md
+++ b/modules/README.md
@@ -3,6 +3,8 @@ jai-modules
 
 Modules for the language being developed by Thekla, Inc.
 
+Available at https://github.com/gudinoff/jai-modules
+
 # Saturation
 
 This module provides basic integer [saturation arithmetic](https://en.wikipedia.org/wiki/Saturation_arithmetic) procedures: `add`, `sub`, `mul`, and `div`.  
diff --git a/ttt.jai b/ttt.jai
index ca78b4b..2bbc90d 100644
--- a/ttt.jai
+++ b/ttt.jai
@@ -14,14 +14,14 @@ DEBUG :: false;
 #import "UTF8";
 TUI :: #import "TUI"(COLOR_MODE_BITS=4);
 
-VERSION             :: "2.2";   // Use only 3 chars (to fit layouts).
+VERSION             :: "3.0";   // Use only 3 chars (to fit layouts).
 YEAR                :: "2024";
 NUM_WEEK_DAYS       :: 7;
 
 APP_FOLDER_NAME     :: "task_time_tracker";
-DB_FILE_NAME        :: "database.bin";
+ST_FILE_NAME        :: "app_state.csv";
+DB_FILE_NAME        :: "database.csv";
 AR_FILE_NAME        :: "archive.csv";
-DB_FILE_SIGN_STR    :: "TTT:B:02";
 
 ASSERT_NOT_NULL     :: "Parameter '%' is null.";
 ASSERT_NOT_EMPTY    :: "Parameter '%' is empty.";
@@ -30,6 +30,7 @@ ASSERT_INVALID_INDEX:: "Invalid index '%'.";
 SECONDS_IN_MINUTE   :: cast(s64)60;
 SECONDS_IN_HOUR     :: cast(s64)60*SECONDS_IN_MINUTE;
 SECONDS_IN_DAY      :: cast(s64)24*SECONDS_IN_HOUR;
+SECONDS_IN_WEEK     :: cast(s64)7*SECONDS_IN_DAY;
 SECONDS_IN_YEAR     :: cast(s64)365*SECONDS_IN_DAY;
 MAX_DATABASE_TASKS  :: S64_MAX;
 
@@ -52,6 +53,7 @@ is_autosave_enabled     := true;
 countdown_to_autosave   := -1;
 first_day_of_week       := 1; // (0-6, Sunday = 0, Monday = 1, ...)
 app_directory           : string;
+st_file_path            : string;
 db_file_path            : string;
 ar_file_path            : string;
 
@@ -173,9 +175,42 @@ hide_processing :: () {
     TUI.tui_write_string(TUI.Commands.TextMode);
 }
 
+// Advance to next item in array.
+advance :: inline (array: *[] $T, amount: int = 1) {
+    assert(amount >= 0);
+    assert(array.count >= amount);
+    array.count -= amount;
+    array.data  += amount;
+}
+
+// Advances to next line and returns it.
+// Taken from Text_File_Handler module.
+// Returns the next line and success.
+consume_next_line :: (sp: *string) -> next_line: string, success: bool {
+    s := sp.*;
+    found, result, right := split_from_left(s, 10,, temporary_allocator);
+
+    if !found {
+        sp.* = "";
+        return s, (s.count > 0);
+    }
+
+    advance(sp, result.count + 1);
+
+    if result {
+        // If there's a carriage return at the end, remove it by decrementing the string's length.
+        if result[result.count-1] == 13  result.count -= 1;
+    }
+    
+    return result, true;
+}
+
 // Returns true if string to_compare is equal to any of the other passed strings, false otherwise.
-is_equal_to_any :: (to_compare :string, test_a :string, test_b :string) -> bool {
-    return to_compare == test_a || to_compare == test_b;
+is_equal_to_any :: (to_compare :string, tests : .. string) -> bool {
+    for tests
+        if to_compare == it
+            return true;
+    return false;
 }
 
 // Count digits required to represent number on base. Sign is discarded.
@@ -292,7 +327,7 @@ add_task :: (db: *Database, task: *Task = null) -> task: *Task, index: s64 {
     
     // If the task belongs to this database, calling array_add might invalidate the pointer
     // because the memory may be reallocated, thus we always use a copy of the task.
-    new_task := ifx task == null then .{} else <<task;
+    new_task := ifx task == null then .{} else task.*;
     array_add(*db.tasks, new_task);
     
     for * db.total_times {
@@ -419,6 +454,17 @@ update_times :: (db: *Database) {
     active_task := get_active_task(db);
 
     if active_task == null return;
+
+    // Performance tweak: if we're updating over more than a week, take a shortcut.
+    if to_seconds(stop_time - start_time) > SECONDS_IN_WEEK {
+        total_weeks := cast,trunc(s64)(to_seconds(stop_time - start_time) / SECONDS_IN_WEEK);
+        elapsed_time_per_weekday := SECONDS_IN_DAY * total_weeks;
+        for 0..NUM_WEEK_DAYS-1 {
+            active_task.times[it]   += elapsed_time_per_weekday;
+            db.total_times[it]      += elapsed_time_per_weekday;
+        }
+        start_time += seconds_to_apollo(total_weeks * SECONDS_IN_WEEK);
+    }
     
     start_week_day: s8;
     while (start_time < stop_time) {
@@ -436,8 +482,8 @@ update_times :: (db: *Database) {
         next_day := start_of_day + #run seconds_to_apollo(SECONDS_IN_DAY);
         next_start := ifx next_day < stop_time then next_day else stop_time;
         elapsed_time := to_seconds(next_start - start_time);
-        active_task.times[start_week_day] += elapsed_time;
-        db.total_times[start_week_day] += elapsed_time;
+        active_task.times[start_week_day]   += elapsed_time;
+        db.total_times[start_week_day]      += elapsed_time;
         
         start_time = next_start;
     }
@@ -447,11 +493,11 @@ update_times :: (db: *Database) {
 update_total_times :: (db: *Database) {
     assert(db != null, ASSERT_NOT_NULL, "db");
     
-    for *total: db.total_times { <<total = 0; }
+    for *total: db.total_times { total.* = 0; }
     
     for task: db.tasks {
         for *total, index: db.total_times {
-            <<total = add(<<total, task.times[index]);
+            total.* = add(total.*, task.times[index]);
         }
     }
 }
@@ -465,8 +511,8 @@ reset_task_times :: (db: *Database, index: s64) {
     update_times(db);
     
     for * db.tasks[index].times {
-        db.total_times[it_index] = sub(db.total_times[it_index], <<it);
-        <<it = 0;
+        db.total_times[it_index] = sub(db.total_times[it_index], it.*);
+        it.* = 0;
     }
 }
 
@@ -512,67 +558,108 @@ add_task_times :: (db: *Database, index: s64, times: [NUM_WEEK_DAYS] s64) {
 reset_database :: (db: *Database) {
     assert(db != null, ASSERT_NOT_NULL, "db");
     array_reset(*db.tasks);
-    <<db = .{};
+    db.* = .{};
 }
 
-// Stores data from database into binary file.
+// Stores application state.
 // Returns success.
-store_database :: (db: Database, path: string) -> success: bool #must {
-    assert(xx path, ASSERT_NOT_EMPTY, "path");
+store_app_state :: (db: Database, st_path: string, db_path: string) -> success: bool #must {
+    assert(xx st_path, ASSERT_NOT_EMPTY, "st_path");
+    assert(xx db_path, ASSERT_NOT_EMPTY, "db_path");
+
+    // Export database to CSV file.
+    if export_to_csv(db, db_path) == false {
+        return false;
+    }
     
-    // Open file.
-    file, open_success := file_open(path, for_writing = true);
-    if open_success == false return false;
-    defer file_close(*file);
+    auto_release_temp();
     
-    file_write(*file, DB_FILE_SIGN_STR);
-    file_write(*file, *db, size_of(Database));
-    file_write(*file, db.tasks.data, size_of(Task) * db.tasks.count);
-
-    return true;
+    builder: String_Builder;
+    append(*builder, "key, value\n"                                         ,, temporary_allocator);
+    print_to_builder(*builder, "active_idx,%\n",        db.active_idx       ,, temporary_allocator);
+    print_to_builder(*builder, "selected_idx,%\n",      db.selected_idx     ,, temporary_allocator);
+    print_to_builder(*builder, "modified_on,%\n",       to_nanoseconds(db.modified_on) ,, temporary_allocator);
+    print_to_builder(*builder, "first_day_of_week,%\n", first_day_of_week   ,, temporary_allocator);
+    
+    return write_entire_file(st_path, *builder);
 }
 
-// Loads data from binary file into database.
+// Loads application state.
 // Returns success.
-load_database :: (db: *Database, path: string) -> success: bool #must {
+load_app_state :: (db: *Database, st_path: string, db_path: string) -> success: bool #must {
     assert(db != null, ASSERT_NOT_NULL, "db");
-    assert(xx path, ASSERT_NOT_EMPTY, "path");
+    assert(xx st_path, ASSERT_NOT_EMPTY, "st_path");
+    assert(xx db_path, ASSERT_NOT_EMPTY, "db_path");
     
-    // Open file.
-    file, open_success := file_open(path);
-    if open_success == false then return false;
-    defer file_close(*file);
+    // Make sure the database clear.
+    reset_database(db);
     
-    // Validate file signature.
-    file_signature: [DB_FILE_SIGN_STR.count] u8;
-    read_success := file_read(file, *file_signature, DB_FILE_SIGN_STR.count);
-    if read_success == false log_error("Failed to read file signature.");
-    if cast(string)file_signature != DB_FILE_SIGN_STR {
-        log_error("Invalid file signature while loading database.");
+    // Load database entries before continuing to load the app state.
+    if import_from_csv(db, db_path) == false {
         return false;
     }
-    
-    // Read database structure.
-    read_success = file_read(file, db, size_of(Database));
-    if read_success == false {
-        log_error("Failed to read database info.");
+
+    // Set default state values.
+    db.modified_on  = current_time_consensus();
+    db.active_idx   = -1;
+    db.selected_idx = -1;
+
+    // Load state file.
+    data, success := read_entire_file(st_path);
+    if success == false {
+        log_error("Failed to read file '%'.", st_path);
         return false;
     }
+    defer free(data);
+
+    // Work on a string struct copy, otherwise the free(data) will fail.
+    csv := data;
     
-    // Reserve database capacity for tasks.
-    tasks_count := db.tasks.count;
-    Initialize(*db.tasks); // Cleanup whatever was read from file.
-    array_reserve(*db.tasks, tasks_count);
+    // Skip header line.
+    consume_next_line(*csv);
     
-    // Read database tasks.
-    file_read(file, db.tasks.data, size_of(Task) * tasks_count);
-    db.tasks.count = tasks_count;
+    // Parse CSV lines.
+    CSV_SEPARATOR : u8 : #char ",";
+    was_modified_on_parsed := false;
+    while (true) {
+        auto_release_temp();
+        
+        line, success := consume_next_line(*csv);
+        if success == false then break;
+        
+        csv_line := split(line, CSV_SEPARATOR,, temporary_allocator);
+        assert(csv_line.count == 2, "Invalid line '%' on file '%'.", line, st_path);
+        
+        // Parse state key and value pairs.
+        key := trim(csv_line[0]);
+        value := csv_line[1];
+        
+        if key == {
+            case "active_idx";
+                db.active_idx = string_to_int(value);
+            case "selected_idx";
+                db.selected_idx = string_to_int(value);
+            case "modified_on";
+                db.modified_on = nanoseconds_to_apollo(string_to_int(value));
+                was_modified_on_parsed = true;
+            case "first_day_of_week";
+                first_day_of_week = abs(string_to_int(value)) % NUM_WEEK_DAYS;
+        }
+        
+        advance(*csv_line);
+    }
     
-    // Make sure we are reading all the file.
-    buffer: u8;
-    success, bytes := file_read(file, *buffer, 1);
-    if bytes > 0 {
-        log_error("Unexpected content found at the end of file '%'.", path);
+    // Adjust selected task.
+    if db.selected_idx < 0 && db.tasks.count > 0    then db.selected_idx = 0;
+    if db.selected_idx >= db.tasks.count            then db.selected_idx = db.tasks.count - 1;
+
+    // Adjust active task.
+    if db.active_idx >= 0 && was_modified_on_parsed == false {
+        log_error("Missing 'modified_on' value on file '%': fix this by adding the 'modified_on', or removing the 'active_idx'.", st_path);
+        return false;
+    }
+    if db.active_idx >= db.tasks.count {
+        log_error("Invalid 'active_idx' '%' detected on file '%'.", db.active_idx, st_path);
         return false;
     }
     
@@ -583,7 +670,7 @@ load_database :: (db: *Database, path: string) -> success: bool #must {
 // Returns success.
 export_to_csv :: (db: Database, path: string) -> success: bool #must {
     assert(xx path, ASSERT_NOT_EMPTY, "path");
-
+    
     auto_release_temp();
     
     builder: String_Builder;
@@ -601,7 +688,7 @@ export_to_csv :: (db: Database, path: string) -> success: bool #must {
         print_to_builder(*builder, "%,%,%,%,%,%,%,%\n",
             name, it.times[0], it.times[1], it.times[2], it.times[3], it.times[4], it.times[5], it.times[6]);
     }
-
+    
     return write_entire_file(path, *builder);
 }
 
@@ -611,33 +698,6 @@ import_from_csv :: (db: *Database, path: string) -> bool #must {
     assert(db != null, ASSERT_NOT_NULL, "db");
     assert(xx path, ASSERT_NOT_EMPTY, "path");
     
-    advance :: inline (array: *[] $T, amount: int = 1) {
-        assert(amount >= 0);
-        assert(array.count >= amount);
-        array.count -= amount;
-        array.data  += amount;
-    }
-
-    // Taken from Text_File_Handler module.
-    consume_next_line :: (sp: *string) -> string, bool {
-        s := << sp;
-        found, result, right := split_from_left(s, 10,, temporary_allocator);
-
-        if !found {
-            << sp = "";
-            return s, (s.count > 0);
-        }
-
-        advance(sp, result.count + 1);
-
-        if result {
-            // If there's a carriage return at the end, remove it by decrementing the string's length.
-            if result[result.count-1] == 13  result.count -= 1;
-        }
-        
-        return result, true;
-    }
-    
     data, success := read_entire_file(path);
     if success == false {
         log_error("Failed to read file '%'.", path);
@@ -650,31 +710,32 @@ import_from_csv :: (db: *Database, path: string) -> bool #must {
     
     // Skip header line.
     consume_next_line(*csv);
-    
+
     // Parse CSV lines.
+    CSV_SEPARATOR : u8 : #char ",";
     while (true) {
         auto_release_temp();
         
         line, success := consume_next_line(*csv);
         if success == false then break;
-        
+
         task: Task;
-        csv_values := split(line, ",",, temporary_allocator);
-        
+        csv_line := split(line, CSV_SEPARATOR,, temporary_allocator);
+
         // Truncate and import task name.
-        task_name := truncate(csv_values[0], task.name.count);
+        task_name := truncate(csv_line[0], task.name.count);
         memcpy(task.name.data, task_name.data, task_name.count);
         
-        advance(*csv_values);
-        for csv_values
+        advance(*csv_line);
+        for csv_line
             task.times[it_index] = string_to_int(it);
-        
+
         add_task(db, *task);
     }
     
     // Adjust selected task.
     if (db.selected_idx < 0 && db.tasks.count > 0) db.selected_idx = 0;
-
+    
     return true;
 }
 
@@ -1103,6 +1164,7 @@ free_memory :: () {
     reset_database(*archive);
     
     free(app_directory);
+    free(st_file_path);
     free(db_file_path);
     free(ar_file_path);
 }
@@ -1144,7 +1206,7 @@ read_input_int :: (y: int, message: string) -> value: int, success: bool {
     
     str := read_input_string(input_pos_x, y, input_width,, temporary_allocator);
     
-    value, success := parse_int(*str);
+    value, success := string_to_int(str);
     return value, success;
 }
 
@@ -1166,7 +1228,7 @@ prompt_user_key :: (y: int, message: string) -> TUI.Key {
 }
 
 main :: () {
-
+    
     #if DEBUG { defer report_memory_leaks(); }
     
     context.logger = print_error;
@@ -1205,24 +1267,31 @@ main :: () {
         }
         
         app_directory = join(base_path, PATH_DELIMITER, APP_FOLDER_NAME);
+        st_file_path = join(app_directory, PATH_DELIMITER, ST_FILE_NAME);
         db_file_path = join(app_directory, PATH_DELIMITER, DB_FILE_NAME);
         ar_file_path = join(app_directory, PATH_DELIMITER, AR_FILE_NAME);
         
-        
         make_directory_if_it_does_not_exist(app_directory, recursive = true);
     }
     
-    { // Initialize database and archive files if needed.
-        if (file_exists(db_file_path) == false) {
-            if (store_database(database, db_file_path) == false) {
+    { // Initialize files if needed.
+        if (file_exists(ar_file_path) == false) {
+            if (export_to_csv(archive, ar_file_path) == false) {
+                log_error("Failed to initialize archive.");
+                exit(1);
+            }
+        }
+        
+        if file_exists(db_file_path) == false {
+            if export_to_csv(database, db_file_path) == false {
                 log_error("Failed to initialize database.");
                 exit(1);
             }
         }
-    
-        if (file_exists(ar_file_path) == false) {
-            if (export_to_csv(archive, ar_file_path) == false) {
-                log_error("Failed to initialize archive.");
+        
+        if file_exists(st_file_path) == false {
+            if store_app_state(database, st_file_path, db_file_path) == false {
+                log_error("Failed to initialize app state.");
                 exit(1);
             }
         }
@@ -1230,143 +1299,143 @@ main :: () {
     
     args :=  get_command_line_arguments();
     defer  array_reset(*args);
+
+    // Iterate over simple commands.
+    for 1..args.count-1 {
+        if is_equal_to_any(args[it], "--help", "-h") {
+            write_strings(
+                "Usage: ttt [OPTION]... [FILE]...\n",
+                "  -i, --import [FILE]           Import CSV file to database (discard first row).\n",
+                "  -e, --export [FILE]           Export database to CSV file.\n",
+                "  -s, --start-of-week [NUMBER]  Set first day of week (0=Sunday, 1=Monday...).\n",
+                "  -n, --no-autosave             Disable autosave feature (only save on exit).\n",
+                "  -h, --help                    Display this help and exit.\n",
+                "  -v, --version                 Output version information and exit.\n",
+                "\n",
+                "In app commands\n",
+                "  w, W                          Archive duplicates and reset all tasks.\n",
+                "  a, A                          Archive selected task (except if active).\n",
+                "  r, R                          Restore selected task from archive.\n",
+                "  t, T                          Select currently active task (if any).\n",
+                "  d, D                          Duplicate selected task.\n",
+                "  c, C                          Coalesce similar tasks.\n",
+                "  n, N                          Create new task.\n",
+                "  m, M                          Move selected task to position.\n",
+                "  g, G                          Select task by position.\n",
+                "  i, I                          Invert tasks order.\n",
+                "  s, S                          Sort tasks by:\n",
+                "                                  n     name;\n",
+                "                                  t     total time;\n",
+                "                                  1..7  time of Nth day of week.\n",
+                "  q, Q                          Save changes and exit.\n",
+                "  F2                            Rename selected task.\n",
+                "  F5                            Recalculate total times.\n",
+                "  TAB                           Toggle archive view.\n",
+                "  BACKSPACE                     Reset times for selected task.\n",
+                "  DELETE                        Delete selected task (except if active).\n",
+                "  SPACE, ENTER                  Toggle selected task as active/inactive.\n",
+                "  1, 2, 3, 4, 5, 6, 7           Edit selected task time for the Nth day of week:\n",
+                "                                  =#    sets # seconds;\n",
+                "                                  -#    subtracts # seconds;\n",
+                "                                  #     adds # seconds;\n",
+                "                                  #m    specifies # as minutes;\n",
+                "                                  #h    specifies # as hours;\n",
+                "                                  #d    specifies # as days;\n",
+                "                                  #y    specifies # as years.\n",
+                "  UP                            Select task above.\n",
+                "  DOWN                          Select task below.\n",
+                "  PAGE-UP                       Select task 1 page above.\n",
+                "  PAGE-DOWN                     Select task 1 page below.\n",
+                "  HOME                          Select first/top task.\n",
+                "  END                           Select last/bottom task.\n",
+                "\n",
+                "Notes\n");
+            print("- All data files are stored in '%'.\n", app_directory);
+            print("  The app state is stored in CSV format on the '%' file.\n", ST_FILE_NAME);
+            print("  The database entries are stored in CSV format on the '%' file.\n", DB_FILE_NAME);
+            print("  The archived entries are stored in CSV format on the '%' file.\n", AR_FILE_NAME);
+            write_strings(
+                "- During intensive operations such as saving or recalculating totals times,\n",
+                "  a diamond symbol is shown on the top left corner.\n"
+            );
+            exit(0);
+        }
+        
+        if is_equal_to_any(args[it], "--version", "-v") {
+            print("Task Time Tracker version % \nCopyright % Daniel Martins\nLicense GPL-3.0-or-later\n", VERSION, YEAR);
+            exit(0);
+        }
+        
+        if is_equal_to_any(args[it], "--no-autosave", "-n") {
+            is_autosave_enabled = false;
+            continue;
+        }
+        
+        // Bypass valid commands that will be parsed later.
+        if is_equal_to_any(args[it], "--import", "-i", "--export", "-e", "--start-of-week", "-s") {
+            it += 1;
+            continue;
+        }
+        
+        log_error("%: invalid option '%'.\nTry '% --help' for more information.", args[0], args[it], args[0]);
+        exit(1);
+    }
     
-    if args.count > 1 {
+    // Load app state.
+    if load_app_state(*database, st_file_path, db_file_path) == false {
+        log_error("Failed to load database.");
+        exit(1);
+    }
+    
+    // Iterate over data sensitive commands.
+    is_exit_requested := false;
+    for 1..args.count-1 {
         
-        is_exit_requested := false;
-        for 1..args.count-1 {
-            if is_equal_to_any(args[it], "--help", "-h") {
-                write_strings(
-                    "Usage: ttt [OPTION]... [FILE]...\n",
-                    "  -i, --import-csv [FILE]       Import CSV file to database (discard first row).\n",
-                    "  -e, --export-csv [FILE]       Export database to CSV file.\n",
-                    "  -s, --start-of-week [NUMBER]  Set first day of week (0=Sunday, 1=Monday...).\n",
-                    "  -n, --no-autosave             Disable autosave feature (only save on exit).\n",
-                    "  -h, --help                    Display this help and exit.\n",
-                    "  -v, --version                 Output version information and exit.\n",
-                    "\n",
-                    "In app commands\n",
-                    "  w, W                          Archive duplicates and reset all tasks.\n",
-                    "  a, A                          Archive selected task (except if active).\n",
-                    "  r, R                          Restore selected task from archive.\n",
-                    "  t, T                          Select currently active task (if any).\n",
-                    "  d, D                          Duplicate selected task.\n",
-                    "  c, C                          Coalesce similar tasks.\n",
-                    "  n, N                          Create new task.\n",
-                    "  m, M                          Move selected task to position.\n",
-                    "  g, G                          Select task by position.\n",
-                    "  i, I                          Invert tasks order.\n",
-                    "  s, S                          Sort tasks by:\n",
-                    "                                  n     name;\n",
-                    "                                  t     total time;\n",
-                    "                                  1..7  time of Nth day of week.\n",
-                    "  q, Q                          Save changes and exit.\n",
-                    "  F2                            Rename selected task.\n",
-                    "  F5                            Recalculate total times.\n",
-                    "  TAB                           Toggle archive view.\n",
-                    "  BACKSPACE                     Reset times for selected task.\n",
-                    "  DELETE                        Delete selected task (except if active).\n",
-                    "  SPACE, ENTER                  Toggle selected task as active/inactive.\n",
-                    "  1, 2, 3, 4, 5, 6, 7           Edit selected task time for the Nth day of week:\n",
-                    "                                  =#    sets # seconds;\n",
-                    "                                  -#    subtracts # seconds;\n",
-                    "                                  #     adds # seconds;\n",
-                    "                                  #m    specifies # as minutes;\n",
-                    "                                  #h    specifies # as hours;\n",
-                    "                                  #d    specifies # as days;\n",
-                    "                                  #y    specifies # as years.\n",
-                    "  UP                            Select task above.\n",
-                    "  DOWN                          Select task below.\n",
-                    "  PAGE-UP                       Select task 1 page above.\n",
-                    "  PAGE-DOWN                     Select task 1 page below.\n",
-                    "  HOME                          Select first/top task.\n",
-                    "  END                           Select last/bottom task.\n",
-                    "\n",
-                    "Notes\n");
-                print("- All data files are stored in '%'.\n", app_directory);
-                write_strings(
-                    "  The database tasks are stored in binary format on the 'database.bin' file.\n",
-                    "  The archived entries are stored in CSV format on the 'archive.csv' file.\n",
-                    "- During intensive operations such as saving or recalculating totals times,\n",
-                    "  a diamond symbol is shown on the top left corner.\n"
-                );
-                exit(0);
-            }
-            
-            if is_equal_to_any(args[it], "--version", "-v") {
-                print("Task Time Tracker version % \nCopyright % Daniel Martins\nLicense GPL-3.0-or-later\n", VERSION, YEAR);
-                exit(0);
-            }
-            
-            if is_equal_to_any(args[it], "--import-csv", "-i") {
-                it += 1;
-                if it >= args.count {
-                    log_error("Missing CSV file path to import.");
-                    exit(1);
-                }
-                if (load_database(*database, db_file_path) == false) {
-                    log_error("Failed to load database during import.");
-                    exit(1);
-                }
-                if (import_from_csv(*database, args[it]) == false) {
-                    log_error("Failed to import CSV file.");
-                    exit(1);
-                }
-                if (store_database(*database, db_file_path) == false) {
-                    log_error("Failed to store database during import.");
-                    exit(1);
-                }
-                reset_database(*database);
-                is_exit_requested = true;
-                continue;
+        if is_equal_to_any(args[it], "--start-of-week", "-s") {
+            it += 1;
+            if it >= args.count {
+                log_error("Missing number for starting day of week.");
+                exit(1);
             }
-            
-            if is_equal_to_any(args[it], "--export-csv", "-e") {
-                it += 1;
-                if it >= args.count {
-                    log_error("Missing CSV file path to export.");
-                    exit(1);
-                }
-                if (load_database(*database, db_file_path) == false) {
-                    log_error("Failed to load database during export.");
-                    exit(1);
-                }
-                if (export_to_csv(*database, args[it]) == false) {
-                    log_error("Failed to export CSV file.");
-                    exit(1);
-                }
-                reset_database(*database);
-                is_exit_requested = true;
-                continue;
+            first_day_of_week = abs(string_to_int(args[it])) % NUM_WEEK_DAYS;
+            continue;
+        }
+        
+        if is_equal_to_any(args[it], "--import", "-i") {
+            it += 1;
+            if it >= args.count {
+                log_error("Missing CSV file path to import.");
+                exit(1);
             }
-
-            if is_equal_to_any(args[it], "--start-of-week", "-s") {
-                it += 1;
-                if it >= args.count {
-                    log_error("Missing number for starting day of week.");
-                    exit(1);
-                }
-                first_day_of_week = parse_int(*args[it]);
-                continue;
+            if import_from_csv(*database, args[it]) == false {
+                log_error("Failed to import CSV file.");
+                exit(1);
             }
-            
-            if is_equal_to_any(args[it], "--no-autosave", "-n") {
-                is_autosave_enabled = false;
-                continue;
+            if export_to_csv(*database, db_file_path) == false {
+                log_error("Failed to store database during import.");
+                exit(1);
             }
-            
-            log_error("%: invalid option '%'.\nTry '% --help' for more information.", args[0], args[it], args[0]);
-            exit(1);
+            is_exit_requested = true;
+            continue;
         }
         
-        if is_exit_requested {
-            exit(0);
+        if is_equal_to_any(args[it], "--export", "-e") {
+            it += 1;
+            if it >= args.count {
+                log_error("Missing CSV file path to export.");
+                exit(1);
+            }
+            if export_to_csv(*database, args[it]) == false {
+                log_error("Failed to export CSV file.");
+                exit(1);
+            }
+            is_exit_requested = true;
+            continue;
         }
     }
     
-    if (load_database(*database, db_file_path) == false) {
-        log_error("Failed to load database.");
-        exit(1);
+    if is_exit_requested {
+        exit(0);
     }
     
     initialize_user_interface();
@@ -1395,11 +1464,11 @@ main :: () {
         }
         
         key := TUI.get_key(INPUT_TIMEOUT_MS);
-
+        
         if key == #char "q" || key == #char "Q" break;
-
+        
         redraw_all = key != TUI.Keys.None;
-
+        
         update_times(*database);
         
         selected_task   := get_selected_task(db);
@@ -1424,11 +1493,11 @@ main :: () {
                         show_processing();
                         if (db == *archive) {
                             if export_to_csv(*archive, ar_file_path) == false {
-                                log_error("Failed to store archive during autosave.");
+                                log_error("Failed to save archive during autosave.");
                             }
                         }
-                        if store_database(database, db_file_path) == false {
-                            log_error("Failed to store database during autosave.");
+                        if store_app_state(database, st_file_path, db_file_path) == false {
+                            log_error("Failed to save database during autosave.");
                         }
                         hide_processing();
                     }
@@ -1809,7 +1878,7 @@ main :: () {
     }
     if (countdown_to_autosave > 0 || is_autosave_enabled == false) {
         while true {
-            if (store_database(database, db_file_path) == false) {
+            if (store_app_state(database, st_file_path, db_file_path) == false) {
                 log_error("Failed to save database, retry?");
                 draw_error_window();
                 if TUI.get_key() == TUI.Keys.Escape then break;
@@ -1819,6 +1888,6 @@ main :: () {
     }
     
     assert(TUI.reset_terminal(), "Failed to reset TUI.");
-
+        
     return;
 }
diff --git a/unused.jai b/unused.jai
index 1f71b37..da8b41d 100644
--- a/unused.jai
+++ b/unused.jai
@@ -48,6 +48,74 @@ print_database :: (db: Database) {
 
 // --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- //
 
+DB_FILE_SIGN_STR    :: "TTT:B:02";
+
+// Stores data from database into binary file.
+// Returns success.
+store_database :: (db: Database, path: string) -> success: bool #must {
+    assert(xx path, ASSERT_NOT_EMPTY, "path");
+    
+    // Open file.
+    file, open_success := file_open(path, for_writing = true);
+    if open_success == false return false;
+    defer file_close(*file);
+    
+    file_write(*file, DB_FILE_SIGN_STR);
+    file_write(*file, *db, size_of(Database));
+    file_write(*file, db.tasks.data, size_of(Task) * db.tasks.count);
+
+    return true;
+}
+
+// Loads data from binary file into database.
+// Returns success.
+load_database :: (db: *Database, path: string) -> success: bool #must {
+    assert(db != null, ASSERT_NOT_NULL, "db");
+    assert(xx path, ASSERT_NOT_EMPTY, "path");
+    
+    // Open file.
+    file, open_success := file_open(path);
+    if open_success == false then return false;
+    defer file_close(*file);
+    
+    // Validate file signature.
+    file_signature: [DB_FILE_SIGN_STR.count] u8;
+    read_success := file_read(file, *file_signature, DB_FILE_SIGN_STR.count);
+    if read_success == false log_error("Failed to read file signature.");
+    if cast(string)file_signature != DB_FILE_SIGN_STR {
+        log_error("Invalid file signature while loading database.");
+        return false;
+    }
+    
+    // Read database structure.
+    read_success = file_read(file, db, size_of(Database));
+    if read_success == false {
+        log_error("Failed to read database info.");
+        return false;
+    }
+    
+    // Reserve database capacity for tasks.
+    tasks_count := db.tasks.count;
+    Initialize(*db.tasks); // Cleanup whatever was read from file.
+    array_reserve(*db.tasks, tasks_count);
+    
+    // Read database tasks.
+    file_read(file, db.tasks.data, size_of(Task) * tasks_count);
+    db.tasks.count = tasks_count;
+    
+    // Make sure we are reading all the file.
+    buffer: u8;
+    success, bytes := file_read(file, *buffer, 1);
+    if bytes > 0 {
+        log_error("Unexpected content found at the end of file '%'.", path);
+        return false;
+    }
+    
+    return true;
+}
+
+// --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- //
+
 
 // Average cumulative calculation.
 average: float64 = 0;