Add front percent command

PluralKit.Bot/Commands/SystemCommands.cs

@@ -172,6 +172,22 @@ namespace PluralKit.Bot.Commands
             await Context.Channel.SendMessageAsync(embed: await EmbedService.CreateFrontHistoryEmbed(sws, system.Zone));
         }
 
+        [Command("frontpercent")]
+        public async Task SystemFrontPercent(string durationStr = "30d")
+        {
+            var system = ContextEntity ?? Context.SenderSystem;
+            if (system == null) throw Errors.NoSystemError;
+
+            var duration = PluralKit.Utils.ParsePeriod(durationStr);
+            if (duration == null) throw Errors.InvalidDateTime(durationStr); 
+            
+            var rangeEnd = SystemClock.Instance.GetCurrentInstant();
+            var rangeStart = rangeEnd - duration.Value;
+            
+            var frontpercent = await Switches.GetPerMemberSwitchDuration(system, rangeEnd - duration.Value, rangeEnd);
+            await Context.Channel.SendMessageAsync(embed: await EmbedService.CreateFrontPercentEmbed(frontpercent, rangeStart.InZone(system.Zone)));
+        }
+
         [Command("timezone")]
         [Remarks("system timezone [timezone]")]
         [MustHaveSystem]

PluralKit.Bot/Errors.cs

@@ -65,5 +65,7 @@ namespace PluralKit.Bot {
         public static PKError InvalidImportFile => new PKError("Imported data file invalid. Make sure this is a .json file directly exported from PluralKit or Tupperbox.");
         public static PKError ImportCancelled => new PKError("Import cancelled.");
         public static PKError MessageNotFound(ulong id) => new PKError($"Message with ID '{id}' not found. Are you sure it's a message proxied by PluralKit?");
+        
+        public static PKError DurationParseError(string durationStr) => new PKError($"Could not parse '{durationStr}' as a valid duration. Try a format such as `30d`, `1d3h` or `20m30s`.");
     }
 }

PluralKit.Bot/Services/EmbedService.cs

@@ -136,5 +136,32 @@ namespace PluralKit.Bot {
                 .WithTimestamp(SnowflakeUtils.FromSnowflake(msg.Message.Mid))
                 .Build();
         }
+
+        public async Task<Embed> CreateFrontPercentEmbed(IDictionary<PKMember, Duration> frontpercent, ZonedDateTime startingFrom)
+        {
+            var totalDuration = SystemClock.Instance.GetCurrentInstant() - startingFrom.ToInstant();
+            
+            var eb = new EmbedBuilder()
+                .WithColor(Color.Blue)
+                .WithFooter($"Since {Formats.ZonedDateTimeFormat.Format(startingFrom)} ({Formats.DurationFormat.Format(totalDuration)} ago)");
+
+            var maxEntriesToDisplay = 24; // max 25 fields allowed in embed - reserve 1 for "others"
+            
+            var membersOrdered = frontpercent.OrderBy(pair => pair.Value).Take(maxEntriesToDisplay).ToList();
+            foreach (var pair in membersOrdered)
+            {
+                var frac = pair.Value / totalDuration;
+                eb.AddField(pair.Key.Name, $"{frac*100:F0}% ({Formats.DurationFormat.Format(pair.Value)})");
+            }
+
+            if (membersOrdered.Count > maxEntriesToDisplay)
+            {
+                eb.AddField("(others)",
+                    Formats.DurationFormat.Format(membersOrdered.Skip(maxEntriesToDisplay)
+                        .Aggregate(Duration.Zero, (prod, next) => prod + next.Value)), true);
+            }
+
+            return eb.Build();
+        }
     }
 }

PluralKit.Core/Stores.cs

@@ -189,13 +189,19 @@ namespace PluralKit {
             }
         }
 
-        public async Task<IEnumerable<PKSwitch>> GetSwitches(PKSystem system, int count)
+        public async Task<IEnumerable<PKSwitch>> GetSwitches(PKSystem system, int count = 9999999)
         {
             // TODO: refactor the PKSwitch data structure to somehow include a hydrated member list
             // (maybe when we get caching in?)
             return await _connection.QueryAsync<PKSwitch>("select * from switches where system = @System order by timestamp desc limit @Count", new {System = system.Id, Count = count});
         }
 
+        public async Task<IEnumerable<int>> GetSwitchMemberIds(PKSwitch sw)
+        {
+            return await _connection.QueryAsync<int>("select member from switch_members where switch = @Switch",
+                new {Switch = sw.Id});
+        }
+        
         public async Task<IEnumerable<PKMember>> GetSwitchMembers(PKSwitch sw)
         {
             return await _connection.QueryAsync<PKMember>(
@@ -215,5 +221,76 @@ namespace PluralKit {
         {
             await _connection.ExecuteAsync("delete from switches where id = @Id", new {Id = sw.Id});
         }
+        
+        public struct SwitchListEntry
+        {
+            public ICollection<PKMember> Members;
+            public Duration TimespanWithinRange;
+        }
+
+        public async Task<IEnumerable<SwitchListEntry>> GetTruncatedSwitchList(PKSystem system, Instant periodStart, Instant periodEnd)
+        {
+            // TODO: only fetch the necessary switches here
+            // todo: this is in general not very efficient LOL
+            // returns switches in chronological (newest first) order
+            var switches = await GetSwitches(system);
+            
+            // we skip all switches that happened later than the range end, and taking all the ones that happened after the range start
+            // *BUT ALSO INCLUDING* the last switch *before* the range (that partially overlaps the range period)
+            var switchesInRange = switches.SkipWhile(sw => sw.Timestamp >= periodEnd).TakeWhileIncluding(sw => sw.Timestamp > periodStart).ToList();
+
+            // query DB for all members involved in any of the switches above and collect into a dictionary for future use
+            // this makes sure the return list has the same instances of PKMember throughout, which is important for the dictionary
+            // key used in GetPerMemberSwitchDuration below
+            var memberObjects = (await _connection.QueryAsync<PKMember>(
+                "select distinct members.* from members, switch_members where switch_members.switch = any(@Switches) and switch_members.member = members.id", // lol postgres specific `= any()` syntax
+                new {Switches = switchesInRange.Select(sw => sw.Id).ToList()}))
+                .ToDictionary(m => m.Id);
+            
+
+            // we create the entry objects
+            var outList = new List<SwitchListEntry>();
+
+            // loop through every switch that *occurred* in-range and add it to the list
+            // end time is the switch *after*'s timestamp - we cheat and start it out at the range end so the first switch in-range "ends" there instead of the one after's start point
+            var endTime = periodEnd;
+            foreach (var switchInRange in switchesInRange)
+            {
+                // find the start time of the switch, but clamp it to the range (only applicable to the Last Switch Before Range we include in the TakeWhileIncluding call above)
+                var switchStartClamped = switchInRange.Timestamp;
+                if (switchStartClamped < periodStart) switchStartClamped = periodStart;
+                
+                var span = endTime - switchStartClamped;
+                outList.Add(new SwitchListEntry
+                {
+                    Members = (await GetSwitchMemberIds(switchInRange)).Select(id => memberObjects[id]).ToList(),
+                    TimespanWithinRange = span
+                });
+                
+                // next switch's end is this switch's start
+                endTime = switchInRange.Timestamp;
+            }
+
+            return outList;
+        }
+
+        public async Task<IDictionary<PKMember, Duration>> GetPerMemberSwitchDuration(PKSystem system, Instant periodStart,
+            Instant periodEnd)
+        {
+            var dict = new Dictionary<PKMember, Duration>();
+            
+            // Sum up all switch durations for each member
+            // switches with multiple members will result in the duration to add up to more than the actual period range
+            foreach (var sw in await GetTruncatedSwitchList(system, periodStart, periodEnd))
+            {
+                foreach (var member in sw.Members)
+                {
+                    if (!dict.ContainsKey(member)) dict.Add(member, sw.TimespanWithinRange);
+                    else dict[member] += sw.TimespanWithinRange;
+                }
+            }
+            
+            return dict;
+        }
     }
 }

PluralKit.Core/Utils.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Security.Cryptography;
 using System.Text.RegularExpressions;
@@ -216,6 +217,17 @@ namespace PluralKit
                 return null;
             }
         }
+        
+        public static IEnumerable<T> TakeWhileIncluding<T>(this IEnumerable<T> list, Func<T, bool> predicate)
+        {
+            // modified from https://stackoverflow.com/a/6817553
+            foreach(var el in list)
+            {
+                yield return el;
+                if (!predicate(el))
+                    yield break;
+            }
+        }
     }
 
     public static class Emojis {
@@ -236,10 +248,10 @@ namespace PluralKit
         // a smaller duration we may only bother with showing <x>h <x>m or <x>m <x>s
         public static IPattern<Duration> DurationFormat = new CompositePatternBuilder<Duration>
         {
-            {DurationPattern.CreateWithInvariantCulture("D'd' h'h'"), d => d.Days > 0},
-            {DurationPattern.CreateWithInvariantCulture("H'h' m'm'"), d => d.Hours > 0},
+            {DurationPattern.CreateWithInvariantCulture("s's'"), d => true},
             {DurationPattern.CreateWithInvariantCulture("m'm' s's'"), d => d.Minutes > 0},
-            {DurationPattern.CreateWithInvariantCulture("s's'"), d => true}
+            {DurationPattern.CreateWithInvariantCulture("H'h' m'm'"), d => d.Hours > 0},
+            {DurationPattern.CreateWithInvariantCulture("D'd' h'h'"), d => d.Days > 0}
         }.Build();
         
         public static IPattern<LocalDateTime> LocalDateTimeFormat = LocalDateTimePattern.CreateWithInvariantCulture("yyyy-MM-dd HH:mm:ss");