Searching database, filtering results, adding longs

My needs outpace my abilities. This code (mostly) works, but it is really ugly, doesn't always add correctly, and is in desperate need of some help refactoring. I can't wrap my head around what needs done with it.

I have a SQLite table WorkLog which contains rows of int, long, long, long, and long. They are _id, unused, dayStartTimestamp, activityStartTime, and activityStopTime. Timestamps are stored as epoch time longs. It is possible to have multiple activities on the same day. I am trying to calculate the total time working in a time period defined by lookBackHours.

Time should be the difference between dayStartTime and activityStopTime + 15 minutes for each day. Since there can be many rows with the same dayStartTime, I want to discard entries with duplicate dayStartTimes, only keeping the row with the longest time between activityStartTime and activityStopTime. I am assuming rows in the db/cursor are sorted by dayStartTime and activityStopTime.

In the code below, activityStartTime is represented by TrackerContract.WorkLog.BLOCK_OUT and activityStopTime is rep by TrackerContract.WorkLog.BLOCK_IN. currentTimeMilliMinutes() can be assumed to be the same as System.currentTimeMillis(), and unrelated to the problem of kludgey, buggy code. It simply takes a System.currentTimeMillis() call, constructs a Calendar, then returns a millisecond time constructed from the calendar's Year, Month, Date, Hour, and Minute (stripping seconds and milliseconds from the time).

Here is the basic logic:

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This method searches a db for entries matching the criteria "anything that ended in lookbackHours+15 minutes, or more recently". It puts them into a List of long[2] arrays, storing the dayStartTime and activityStopTime in position 0 and 1 in the array.

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The next loop goes through and attempts to throw away a list entry if the next one has the same dayStartTime and a higher (more recent) `activitySto

Your code is a bit too messy to understand what you are doing - or why you are doing it, but here are some pointers that can get you started:

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Your method is way too long. Break it up into a couple of sub-methods.

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Using a List and using the indexes 0 and 1 for that long[] like you are doing tells me that you should instead use a class to represent your values in the long[]. This will make it a lot clearer about what the 0 index actually is. (Assuming you use proper naming for it)

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Your indentation is a bit off. All the code in your method should be indented one step.

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In your for-loop, you can use:

for (int i = 0; i = length)
        continue;

To get rid of the else statement entirely.

As I said, this is just a start. I am still not sure about what it actually is that you are doing, but this will be more clear once you divide your method into a couple of sub-methods.

StackExchange Code Review Q#37787, answer score: 5