How to assign each item with the keys in map - string

Question

I'm storing (non personal) data in a list of Strings which is given values by the user once an action is carried out.
Since the List is only given values once the user performs the action I don't know how many items there will be.
I'm trying to sort this List into two types of data:
Strings and DateTime
I've been trying to convert the list into a Map but I'm not sure how to assign each item with the keys "appname" and "durations". How would do you this?
Please suggest a better way of solving this issue, if there is one?
***Updated
Data example:
YouTube
1h 20m on screen - 2m background
1h 22m
Chrome
1h 26m on screen - 10m background
1h 36m
Google Maps
3h 4m on screen - 2h 54m background
5h 58m
The data is stored using a final List<String> _usage.
** Update: added example of what data should be parsed and how to access it.
Im looking to parse this data as json:
{"app": "YouTube", "duration": "1h 22m"},
//Removes the'1h 20m on screen - 2m background'
{"app": "Chrome", "duration": "1h 36m"},
//Removes the '1h 26m on screen - 10m background'
{"app": "Google Maps", "duration": "5h 58m")"}
//Removes the '3h 4m on screen - 2h 54m background'
I'd preferably like to access it through a Map or HashMap type.

Answer 1

I guess you could make something like this but it is difficult to make a stable solution without knowing all pitfalls in the data. E.g. I assume we always can guarantee that the name of the app comes first and then at some point some duration:
List<String> _usage = [
'YouTube',
'1h 20m on screen - 2m background',
'1h 22m',
'Chrome',
'1h 26m on screen - 10m background',
'1h 36m',
'Google Maps',
'3h 4m on screen - 2h 54m background',
'5h 58m'
];
void main(List arguments) {
final map = <String, Duration>{};
for (var i = 0; i < _usage.length; i += 3) {
final app = _usage[i];
final duration = _parseDuration(_usage[i + 2]);
if (map.containsKey(app)) {
map[app] += duration;
} else {
map[app] = duration;
}
}
// {YouTube: 1:22:00.000000, Chrome: 1:36:00.000000, Google Maps: 5:58:00.000000}
print(map);
}
final _regExp = RegExp(r'(?<hours>\d+)h (?<minutes>\d+)m');
Duration _parseDuration(String line) {
final match = _regExp.firstMatch(line);
if (match == null) {
throw Exception('Could not get duration from: $line');
}
return Duration(
hours: int.parse(match.namedGroup('hours')),
minutes: int.parse(match.namedGroup('minutes')));
}
I also added to the solution so if the same app name comes up, we add the duration instead of overwriting the previous value.