feat(quest): QT2/QT4 — the contract catalog, and retail's progress column

The wire carries an id, a stage and two timers. Every word the player reads
lives in portal.dat's ContractTable, which nothing in the tree had ever
opened — the only reference counted its entries in a CLI diagnostic. Chorizite
does decode it (322 contracts installed), which was a real question given it
declares TabooTable without decoding it.

FillProgressString @0x00498DE0 is the one real algorithm in this panel, and it
is now ported whole. Its x87 compares are the usual fcom/sahf pattern, so the
(status & 0x41) tests decode as "<= 0" rather than "< 0" — the difference
between a cooldown that expires and one that never does.

Three readings recorded as tests because each looks like a mistake:
TimeWhenDone is on the wire and is never read; an EMPTY QuestflagRepeatTime is
the entire difference between "Done" and "Available"; and DescriptionProgress
is a printf format taking stage-4, not a literal — rendering it verbatim shows
the player "%d/20 Tuskers".

DeltaTimeToString @0x00565E10 emits every part with a trailing space and then
overwrites the last one. That truncation is invisible in the decompiler output
(the instruction reads as pointer noise), so it was settled by decoding the
bytes: mov byte ptr [esp+eax+0x1b], cl with cl == 0 and eax == strlen writes
the terminator over buffer[len-1]. Guessing either way was a coin flip that
decides whether every repeat timer reads "Done (1h 30s  to Repeat)".

The single-%d substitution is a MEASUREMENT, not a convenience: 89 of the 322
installed contracts author a progress format and every one uses exactly one
specifier. An installed-DAT test asserts that, so a future dat that ships two
fails there rather than silently rendering a raw specifier.

LayoutDump gained --contracts, which is how all of the above was measured.

Campaign QT slices 2 and 4 of 6.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/AcDream.Content/ContractTableReader.cs

@@ -0,0 +1,69 @@
+using System.Collections.Frozen;
+using System.Collections.Generic;
+using AcDream.Core.Quests;
+using DatContractTable = DatReaderWriter.DBObjs.ContractTable;
+
+namespace AcDream.Content;
+
+/// <summary>
+/// Projects portal.dat's ContractTable into acdream's presentation-free
+/// <see cref="ContractCatalog"/>.
+/// </summary>
+/// <remarks>
+/// Same shape as <see cref="CharGen.ChargenTableReader"/> and
+/// <c>MagicCatalog.Load</c>: one static entry point over
+/// <see cref="IDatReaderWriter"/>, frozen at projection, and no Chorizite
+/// types crossing into the returned model.
+/// <para>
+/// Nothing read this table before Campaign QT — the only reference in the tree
+/// counted its entries in a CLI diagnostic. The installed build holds 322
+/// contracts.
+/// </para>
+/// </remarks>
+public static class ContractTableReader
+{
+    /// <summary>
+    /// Retail's ContractTable dat id (ACE:
+    /// <c>ACE.DatLoader.FileTypes.ContractTable.FILE_ID</c>).
+    /// </summary>
+    public const uint ContractTableDid = 0x0E00001Du;
+
+    /// <summary>
+    /// Loads the installed contract catalog, or
+    /// <see cref="ContractCatalog.Empty"/> when the table is absent.
+    /// </summary>
+    /// <remarks>
+    /// An absent table is not fatal. It costs the player the contract NAMES,
+    /// not the tracker: the wire state stands on its own, and the panel still
+    /// has stages and timers to draw.
+    /// </remarks>
+    public static ContractCatalog Load(IDatReaderWriter dats)
+    {
+        ArgumentNullException.ThrowIfNull(dats);
+
+        DatContractTable? table = dats.Get<DatContractTable>(ContractTableDid);
+        if (table is null || table.Contracts.Count == 0)
+            return ContractCatalog.Empty;
+
+        var projected = new Dictionary<uint, ContractEntry>(table.Contracts.Count);
+        foreach ((uint key, DatReaderWriter.Types.Contract contract) in table.Contracts)
+        {
+            projected[key] = new ContractEntry(
+                contract.Version,
+                contract.ContractId,
+                contract.ContractName ?? string.Empty,
+                contract.Description ?? string.Empty,
+                contract.DescriptionProgress ?? string.Empty,
+                contract.NameNPCStart ?? string.Empty,
+                contract.NameNPCEnd ?? string.Empty,
+                contract.QuestflagStamped ?? string.Empty,
+                contract.QuestflagStarted ?? string.Empty,
+                contract.QuestflagFinished ?? string.Empty,
+                contract.QuestflagProgress ?? string.Empty,
+                contract.QuestflagTimer ?? string.Empty,
+                contract.QuestflagRepeatTime ?? string.Empty);
+        }
+
+        return new ContractCatalog(projected.ToFrozenDictionary());
+    }
+}

src/AcDream.Core/Quests/ContractEntry.cs

@@ -0,0 +1,73 @@
+using System.Collections.Generic;
+
+namespace AcDream.Core.Quests;
+
+/// <summary>
+/// One contract's authored description, from portal.dat's ContractTable.
+/// </summary>
+/// <remarks>
+/// <para>
+/// The wire carries only an id, a stage and two timers — every word the player
+/// reads comes from here, keyed by <see cref="ContractId"/>.
+/// </para>
+/// <para>
+/// The <c>Questflag*</c> names are the server's own bookkeeping. The client
+/// never reads or writes a quest flag (<c>r10-quest-dialogs.md</c> §1.3); it
+/// keeps the names because <c>gmContractsUI::FillProgressString @0x00498DE0</c>
+/// branches on whether <see cref="QuestflagRepeatTime"/> is EMPTY, which is how
+/// it tells "finished for good" from "finished for now".
+/// </para>
+/// </remarks>
+public sealed record ContractEntry(
+    uint Version,
+    uint ContractId,
+    string ContractName,
+    string Description,
+    /// <summary>
+    /// A printf format, NOT a literal — retail feeds it one integer
+    /// (<c>stage - 4</c>). The installed table has entries like
+    /// <c>"%d/20 Tuskers"</c>. Rendering it verbatim shows the player a raw
+    /// format specifier.
+    /// </summary>
+    string DescriptionProgress,
+    string NameNpcStart,
+    string NameNpcEnd,
+    string QuestflagStamped,
+    string QuestflagStarted,
+    string QuestflagFinished,
+    string QuestflagProgress,
+    string QuestflagTimer,
+    string QuestflagRepeatTime)
+{
+    public static readonly ContractEntry Unknown = new(
+        0u, 0u,
+        string.Empty, string.Empty, string.Empty,
+        string.Empty, string.Empty,
+        string.Empty, string.Empty, string.Empty,
+        string.Empty, string.Empty, string.Empty);
+}
+
+/// <summary>The installed contract catalog, keyed by contract id.</summary>
+public sealed class ContractCatalog(IReadOnlyDictionary<uint, ContractEntry> contracts)
+{
+    public static readonly ContractCatalog Empty =
+        new(new Dictionary<uint, ContractEntry>());
+
+    public IReadOnlyDictionary<uint, ContractEntry> Contracts { get; } = contracts;
+
+    public int Count => Contracts.Count;
+
+    /// <summary>
+    /// The entry for <paramref name="contractId"/>, or
+    /// <see cref="ContractEntry.Unknown"/>.
+    /// </summary>
+    /// <remarks>
+    /// A miss is normal rather than exceptional: the server may track a
+    /// contract this client's dat build has never heard of, and the panel still
+    /// has to draw the row.
+    /// </remarks>
+    public ContractEntry Lookup(uint contractId) =>
+        Contracts.TryGetValue(contractId, out ContractEntry? entry)
+            ? entry
+            : ContractEntry.Unknown;
+}

src/AcDream.Core/Quests/ContractProgressText.cs

@@ -0,0 +1,160 @@
+using System;
+using System.Globalization;
+using System.Text;
+
+namespace AcDream.Core.Quests;
+
+/// <summary>
+/// The contract tracker's progress column — a faithful port of
+/// <c>gmContractsUI::FillProgressString @0x00498DE0</c>.
+/// </summary>
+public static class ContractProgressText
+{
+    private const int SecondsPerMonth = 0x278D00;   // 2,592,000 — a 30-day month
+    private const int SecondsPerDay = 0x15180;      // 86,400
+    private const int SecondsPerHour = 0xE10;       // 3,600
+    private const int SecondsPerMinute = 0x3C;      // 60
+
+    /// <summary>
+    /// Port of <c>ClientUISystem::DeltaTimeToString @0x00565E10</c>.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// Largest-unit-first, each unit omitted when zero, seconds always shown:
+    /// <c>"2d 3h 4m 5s"</c>, <c>"45s"</c>. A "month" is a flat 30 days.
+    /// </para>
+    /// <para>
+    /// Every part is emitted with a TRAILING space and the final one is then
+    /// truncated. That truncation is not visible in the decompiler output —
+    /// the instruction reads as noise — so it was settled by decoding the
+    /// bytes: at <c>0x00565F0E</c>, <c>mov byte ptr [esp+eax+0x1b], cl</c>
+    /// with <c>cl == 0</c> and <c>eax == strlen</c> writes the terminator over
+    /// <c>buffer[len - 1]</c>. Without it, the caller composes
+    /// <c>"Done (1h 30s  to Repeat)"</c> with a double space.
+    /// </para>
+    /// </remarks>
+    public static string DeltaTimeToString(double seconds)
+    {
+        // Retail's _ftol2 — truncation toward zero, matching a C cast.
+        long total = (long)seconds;
+        if (total < 0) total = 0;
+
+        long months = total / SecondsPerMonth;
+        long rest = total % SecondsPerMonth;
+        long days = rest / SecondsPerDay;
+        rest %= SecondsPerDay;
+        long hours = rest / SecondsPerHour;
+        rest %= SecondsPerHour;
+        long minutes = rest / SecondsPerMinute;
+        long secs = rest % SecondsPerMinute;
+
+        var text = new StringBuilder();
+        if (months != 0) Append(text, months, "mo");
+        if (days != 0) Append(text, days, "d");
+        if (hours != 0) Append(text, hours, "h");
+        if (minutes != 0) Append(text, minutes, "m");
+        Append(text, secs, "s");
+
+        // The trailing space the last part just wrote.
+        return text.ToString(0, text.Length - 1);
+
+        static void Append(StringBuilder text, long value, string unit)
+        {
+            text.Append(value.ToString(CultureInfo.InvariantCulture));
+            text.Append(unit);
+            text.Append(' ');
+        }
+    }
+
+    /// <summary>
+    /// The progress text for one tracked contract.
+    /// </summary>
+    /// <param name="stage">
+    /// The wire stage. Deliberately a raw <c>uint</c> rather than an enum:
+    /// retail encodes a progress COUNTER as <c>4 + n</c>, so the values above
+    /// three are data, not names.
+    /// </param>
+    /// <param name="timeWhenRepeats">Seconds until the repeat cooldown ends.</param>
+    /// <param name="receivedAt">When this state arrived — the countdown anchor.</param>
+    /// <param name="entry">The authored contract, or
+    /// <see cref="ContractEntry.Unknown"/>.</param>
+    /// <param name="now">The current time.</param>
+    /// <remarks>
+    /// <para>
+    /// Two details worth stating because they look like mistakes:
+    /// </para>
+    /// <para>
+    /// <b><c>TimeWhenDone</c> is never read.</b> Only <c>TimeWhenRepeats</c>
+    /// reaches this text. The other timer is on the wire and simply does not
+    /// drive the progress column.
+    /// </para>
+    /// <para>
+    /// <b>An empty <c>QuestflagRepeatTime</c> is what distinguishes "Done"
+    /// from "Available".</b> A contract with no repeat flag is finished for
+    /// good; one with a repeat flag whose timer has run out is offered again.
+    /// </para>
+    /// </remarks>
+    public static string Build(
+        uint stage,
+        double timeWhenRepeats,
+        DateTime receivedAt,
+        ContractEntry entry,
+        DateTime now)
+    {
+        ArgumentNullException.ThrowIfNull(entry);
+
+        if (stage == 1u) return "Available";
+        if (stage == 2u) return "In Progress";
+
+        if (stage == 3u)
+        {
+            if (timeWhenRepeats <= 0d)
+            {
+                return entry.QuestflagRepeatTime.Length == 0 ? "Done" : "Available";
+            }
+
+            // Retail counts down from when the state ARRIVED, using its own
+            // clock — the server never sends that instant.
+            double elapsed = (now - receivedAt).TotalSeconds;
+            double remaining = timeWhenRepeats - elapsed;
+            if (remaining <= 0d) return "Available";
+
+            return $"Done ({DeltaTimeToString(remaining)} to Repeat)";
+        }
+
+        if (stage >= 4u)
+        {
+            // A counter with nothing authored to put it in.
+            if (entry.DescriptionProgress.Length == 0) return "In Progress";
+            return FormatProgress(entry.DescriptionProgress, stage - 4u);
+        }
+
+        // Stage 0 or anything else: retail returns without writing, leaving the
+        // caller's string as it found it.
+        return string.Empty;
+    }
+
+    /// <summary>
+    /// Substitutes retail's single integer argument into an authored progress
+    /// format.
+    /// </summary>
+    /// <remarks>
+    /// <c>FillProgressString</c> passes exactly ONE integer, so only the first
+    /// <c>%d</c> can be honoured — a second specifier would read past the
+    /// argument in retail too. Measured against the installed table: 89 of 322
+    /// contracts author a progress format and every one uses exactly one
+    /// <c>%d</c> (e.g. <c>"%d/20 Tuskers"</c>), so the single-substitution
+    /// reading covers the whole shipped catalog rather than merely the common
+    /// case.
+    /// </remarks>
+    private static string FormatProgress(string format, uint value)
+    {
+        int at = format.IndexOf("%d", StringComparison.Ordinal);
+        if (at < 0) return format;
+
+        return string.Concat(
+            format.AsSpan(0, at),
+            value.ToString(CultureInfo.InvariantCulture),
+            format.AsSpan(at + 2));
+    }
+}