Merge pull request #5 from raleighlittles/feature/adding-language-sup…

…port-to-preferences-file

Added support for parsing languages from Preferences file

parser/Cargo.toml

@@ -8,3 +8,6 @@ edition = "2021"
 [dependencies]
 chrono = "0.4.31"
 csv = "1.3.0"
+
+# Languages parsing
+isolang = "2.4.0"

parser/src/constants/preferences_constants.rs

@@ -30,4 +30,4 @@ pub const VOLUME_LIMIT_OFFSET : usize = 2896; // 0xB50
 pub const VOLUME_LIMIT_LEN : usize = 1;
 
 pub const REGION_OFFSET : usize = 2928; // 0xB70
-pub const REGION_LEN : usize = 1;
+pub const REGION_LEN : usize = 2;

parser/src/parsers/preferences_parser.rs

@@ -72,9 +72,9 @@ pub fn parse_preferences_file(itunesdb_file_as_bytes: Vec<u8>) {
 
         println!("Daylight Savings Time enabled?: {}", preferences::is_daylight_savings_enabled(dst_setting_raw as u8));
 
-        let language_selection_idx = helpers::get_slice_as_le_u32(idx, &itunesdb_file_as_bytes, preferences_constants::LANGUAGE_SELECTION_OFFSET, preferences_constants::LANGUAGE_SELECTION_LEN);
+        let lang_selection_idx = helpers::get_slice_as_le_u32(idx, &itunesdb_file_as_bytes, preferences_constants::LANGUAGE_SELECTION_OFFSET, preferences_constants::LANGUAGE_SELECTION_LEN);
 
-        println!("Selected language idx: {}", language_selection_idx);
+        println!("Selected language idx: {} ~ Parses to '{}'", lang_selection_idx, preferences::decode_language_from_idx(lang_selection_idx as u8));
 
         let tz_info_raw = helpers::get_slice_as_le_u32(idx, &itunesdb_file_as_bytes, preferences_constants::TIMEZONE_INFO_OFFSET, preferences_constants::TIMEZONE_INFO_LEN);
 

parser/src/preferences.rs

@@ -5,7 +5,6 @@
  * Provides functionality for working with the Preferences file
  */
 
-use std::num::Wrapping;
 
 pub fn is_daylight_savings_enabled(raw_dst_setting : u8) -> bool {
 
@@ -14,11 +13,56 @@ pub fn is_daylight_savings_enabled(raw_dst_setting : u8) -> bool {
     return raw_dst_setting == dst_enabled_val;
 }
 
+/// This function is a little bit dubious, the logic for it was added in a comment on the original documentation
+/// and I get invalid values with it sometimes.
 pub fn decode_timezone(raw_timezone_info : u8) -> u8 {
 
     let gmt_timezone_const = 0x19; // 25d, supposed to represent GMT (UTC+0)
 
-    let timezone_hour = (Wrapping(raw_timezone_info)) - Wrapping(gmt_timezone_const);
+    let timezone_hour = (std::num::Wrapping(raw_timezone_info)) - std::num::Wrapping(gmt_timezone_const);
 
     return timezone_hour.0 / 2;
+}
+
+/// This was a little bit tricky to figure out. The index comes from when the device starts up for the first time, and
+/// asks you to choose the language list.
+/// I couldn't find anywhere this was documented so I ended up having to find an old iPod myself, reset it, and scroll
+/// through the list of available languages.
+/// Note that interestingly, the string tables on the iPod (stored in the UISS_combined.plist file) have the language strings
+/// installed for "Thai" (`th-TH`), even though in the settings you can't actually change the device to that language.
+pub fn decode_language_from_idx(lang_idx : u8) -> String {
+
+    let selected_lang : Option<isolang::Language> = match lang_idx {
+        0_u8 | 1_u8 => isolang::Language::from_639_1("en"),
+        2_u8 => isolang::Language::from_639_1("ja"),
+        3_u8 => isolang::Language::from_639_1("cs"),
+        4_u8 => isolang::Language::from_639_1("da"),
+        5_u8 => isolang::Language::from_639_1("de"),
+        6_u8 => isolang::Language::from_639_1("es"),
+        7_u8 => isolang::Language::from_639_1("fr"),
+        8_u8 => isolang::Language::from_639_1("el"),
+        9_u8 => isolang::Language::from_639_1("hr"),
+        10_u8 =>isolang::Language::from_639_1("it"),
+        11_u8 => isolang::Language::from_639_1("hu"),
+        12_u8 => isolang::Language::from_639_1("nl"),
+        13_u8 => isolang::Language::from_639_1("no"),
+        14_u8 | 15_u8 => isolang::Language::from_639_1("pt"),
+        16_u8 => isolang::Language::from_639_1("ru"),
+        17_u8 => isolang::Language::from_639_1("pl"),
+        18_u8 => isolang::Language::from_639_1("ro"),
+        19_u8 => isolang::Language::from_639_1("sk"),
+        20_u8 => isolang::Language::from_639_1("fi"),
+        21_u8 => isolang::Language::from_639_1("sv"),
+        22_u8 => isolang::Language::from_639_1("tr"),
+        23_u8 => isolang::Language::from_639_1("ar"),
+        24_u8 => isolang::Language::from_639_1("ko"),
+        25_u8 | 26_u8 | 27_u8 => isolang::Language::from_639_1("zh"),
+        28_u8 => isolang::Language::from_639_1("he"),
+        unknown_lang_code => {
+            panic!("'{}' is not a valid ISO-639-1 language code", unknown_lang_code);
+        }
+
+    };
+
+    return selected_lang.unwrap().to_name().to_string();
 }