Refactor scene and pattern collection logic to use group patterns instead of intermediate scenes data

src/lib/parsers.ts

@@ -301,17 +301,116 @@ export function parsePatternEvents(data: Uint8Array, startOffset: number = 4): P
   };
 }
 
-function getPatternsForScene(scenesIntermediate: IntermediateScenes, scenePatternUsage: SceneMeta) {
+function getPatternKey(group: Group, patternNumber: number) {
+  return `${group}${patternNumber}`;
+}
+
+function normalizeTimeSignature(
+  numerator: number,
+  denominator: number,
+  fallback: TimeSignature,
+): TimeSignature {
+  const validNumerator = Number.isInteger(numerator) && numerator > 0 && numerator <= 99;
+  const validDenominator =
+    Number.isInteger(denominator) &&
+    denominator > 0 &&
+    denominator <= 64 &&
+    (denominator & (denominator - 1)) === 0;
+
+  return {
+    numerator: validNumerator ? numerator : fallback.numerator,
+    denominator: validDenominator ? denominator : fallback.denominator,
+  };
+}
+
+function collectSceneRecords(data: Uint8Array): SceneRecord[] {
+  const headerTimeSignature = normalizeTimeSignature(
+    data[5],
+    data[6],
+    defaultScenesSettings.timeSignature,
+  );
+  const sceneRecords: SceneRecord[] = [];
+
+  for (let sceneIndex = 0; sceneIndex < 99; sceneIndex++) {
+    const offset = 7 + sceneIndex * 6;
+    if (offset + 6 > data.length) {
+      break;
+    }
+
+    const patternNumbers: Record<Group, number> = {
+      a: data[offset],
+      b: data[offset + 1],
+      c: data[offset + 2],
+      d: data[offset + 3],
+    };
+
+    if (!projectGroups.some((group) => patternNumbers[group] !== 0)) {
+      continue;
+    }
+
+    sceneRecords.push({
+      number: sceneIndex + 1,
+      patternNumbers,
+      timeSignature: normalizeTimeSignature(
+        data[offset + 4],
+        data[offset + 5],
+        headerTimeSignature,
+      ),
+    });
+  }
+
+  return sceneRecords;
+}
+
+function collectGroupPatterns(files: TarFile[], sku: string): GroupPattern[] {
+  const groupPatterns = new Map<string, GroupPattern>();
+
+  for (const file of files) {
+    if (file.type !== 'file' || !file.data) {
+      continue;
+    }
+
+    const matches = file.name.match(/^patterns\/([abcd])(\d{1,2})$/);
+    if (!matches) {
+      continue;
+    }
+
+    const group = matches[1] as Group;
+    const patternNumber = Number(matches[2]);
+    if (patternNumber < 1 || patternNumber > 99) {
+      continue;
+    }
+
+    const parsedPattern = parsePatternEvents(file.data, sku === SKU_EP40 ? 6 : 4);
+    groupPatterns.set(getPatternKey(group, patternNumber), {
+      group,
+      patternNumber,
+      ...parsedPattern,
+    });
+  }
+
+  return [...groupPatterns.values()].toSorted((a, b) => {
+    const numberDifference = a.patternNumber - b.patternNumber;
+    if (numberDifference !== 0) {
+      return numberDifference;
+    }
+
+    return projectGroups.indexOf(a.group) - projectGroups.indexOf(b.group);
+  });
+}
+
+function getPatternsForScene(
+  groupPatterns: Map<string, GroupPattern>,
+  patternNumbers: Record<Group, number>,
+) {
   const patterns: Pattern[] = [];
 
-  for (const group of ['a', 'b', 'c', 'd'] as const) {
+  for (const group of projectGroups) {
-    const scene = scenePatternUsage[group];
+    const groupPattern = groupPatterns.get(getPatternKey(group, patternNumbers[group]));
-    const lookupSceneData = scenesIntermediate[scene];
 
-    if (lookupSceneData?.groups[group]) {
+    if (groupPattern) {
-      const groupData = lookupSceneData.groups[group];
+      const sources = new Set(Object.keys(groupPattern.notes).map(Number));
-      const sources = new Set(Object.keys(groupData.notes).map(Number));
+      groupPattern.events.forEach((event) => {
-      groupData.events.forEach((event) => {
         if (event.type === 'midi' && event.source >= 0 && event.source < 12) {
           sources.add(event.source);
         }
@@ -321,8 +420,8 @@ function getPatternsForScene(scenesIntermediate: IntermediateScenes, scenePatter
         patterns.push({
           pad: `${group}${padNum}` as PadCode,
           group,
-          notes: groupData.notes[padNum] || [],
+          notes: groupPattern.notes[padNum] || [],
-          bars: groupData.bars,
+          bars: groupPattern.bars,
         });
       });
     }
@@ -332,22 +431,22 @@ function getPatternsForScene(scenesIntermediate: IntermediateScenes, scenePatter
 }
 
 function getPatternEventsForScene(
-  scenesIntermediate: IntermediateScenes,
+  groupPatterns: Map<string, GroupPattern>,
-  scenePatternUsage: SceneMeta,
+  patternNumbers: Record<Group, number>,
 ) {
   const patternEvents: Partial<Record<Group, SceneGroupPatternData>> = {};
 
-  for (const group of ['a', 'b', 'c', 'd'] as const) {
+  for (const group of projectGroups) {
-    const patternNumber = scenePatternUsage[group];
+    const patternNumber = patternNumbers[group];
-    const groupData = scenesIntermediate[patternNumber]?.groups[group];
+    const groupPattern = groupPatterns.get(getPatternKey(group, patternNumber));
 
-    if (groupData) {
+    if (groupPattern) {
       patternEvents[group] = {
         group,
         patternNumber,
-        bars: groupData.bars,
+        bars: groupPattern.bars,
-        recordCount: groupData.recordCount,
+        recordCount: groupPattern.recordCount,
-        events: groupData.events,
+        events: groupPattern.events,
       };
     }
   }
@@ -355,90 +454,90 @@ function getPatternEventsForScene(
   return patternEvents;
 }
 
-export function collectScenesAndPatterns(files: TarFile[], sku: string) {
+function buildScene(
-  const scenesIntermediateData: IntermediateScenes = {};
+  sceneRecord: SceneRecord,
-  const scenes: Record<string, Scene> = {};
+  groupPatterns: Map<string, GroupPattern>,
-  const scenePatternUsage: Record<string, SceneMeta> = {};
+): Scene {
-
+  return {
-  // build default scene metadata (in case "scenes" file is missing)
+    number: sceneRecord.number,
-  for (let i = 1; i <= 99; i++) {
+    name: String(sceneRecord.number).padStart(2, '0'),
-    scenePatternUsage[i] = {
+    patternNumbers: sceneRecord.patternNumbers,
-      a: i,
+    timeSignature: sceneRecord.timeSignature,
-      b: i,
+    patterns: getPatternsForScene(groupPatterns, sceneRecord.patternNumbers),
-      c: i,
+    patternEvents: getPatternEventsForScene(groupPatterns, sceneRecord.patternNumbers),
-      d: i,
   };
+}
+
+function collectSongPositions(data: Uint8Array): SongPosition[] {
+  const songCountOffset = 612;
+  const firstSongPositionOffset = 613;
+  if (data.length <= songCountOffset) {
+    return [];
   }
 
-  // build group/pattern lookup table
+  const availablePositions = Math.max(0, data.length - firstSongPositionOffset);
-  const scenesFile = files.find((f) => f.name === 'scenes' && f.type === 'file');
+  const songCount = Math.min(data[songCountOffset], 99, availablePositions);
+  if (songCount === 1 && data[firstSongPositionOffset] === 1) {
+    return [];
+  }
+
+  const songPositions: SongPosition[] = [];
+
+  for (let index = 0; index < songCount; index++) {
+    const sceneNumber = data[firstSongPositionOffset + index];
+    if (sceneNumber < 1 || sceneNumber > 99) {
+      continue;
+    }
+
+    songPositions.push({
+      position: index + 1,
+      sceneNumber,
+    });
+  }
+
+  return songPositions;
+}
+
+export function collectProjectStructure(files: TarFile[], sku: string) {
+  const groupPatterns = collectGroupPatterns(files, sku);
+  const groupPatternLookup = new Map(
+    groupPatterns.map((pattern) => [getPatternKey(pattern.group, pattern.patternNumber), pattern]),
+  );
+  const scenesFile = files.find((file) => file.name === 'scenes' && file.type === 'file');
+  let sceneRecords: SceneRecord[];
+
   if (scenesFile?.data) {
-    const chunks = chunkArray(scenesFile.data, 6, 7);
+    sceneRecords = collectSceneRecords(scenesFile.data);
-    chunks.forEach((chunk, i) => {
+  } else {
-      if (i > 98) {
+    const patternNumbers = [...new Set(groupPatterns.map((pattern) => pattern.patternNumber))]
-        return;
+      .toSorted((a, b) => a - b);
-      }
+    sceneRecords = patternNumbers.map((patternNumber) => ({
-
+      number: patternNumber,
-      scenePatternUsage[i + 1] = {
+      patternNumbers: {
-        a: chunk[0],
+        a: groupPatternLookup.has(getPatternKey('a', patternNumber)) ? patternNumber : 0,
-        b: chunk[1],
+        b: groupPatternLookup.has(getPatternKey('b', patternNumber)) ? patternNumber : 0,
-        c: chunk[2],
+        c: groupPatternLookup.has(getPatternKey('c', patternNumber)) ? patternNumber : 0,
-        d: chunk[3],
+        d: groupPatternLookup.has(getPatternKey('d', patternNumber)) ? patternNumber : 0,
-      };
-    });
-  }
-
-  for (const file of files) {
-    if (!file.name.startsWith('patterns') || file.type !== 'file' || !file.data) {
-      continue;
-    }
-
-    const matches = file.name.match(/patterns\/([abcd])(\d+)/);
-    if (!matches) {
-      continue;
-    }
-
-    const [, group, scene] = matches;
-    const sceneIndex = Number(scene);
-    if (!scenesIntermediateData[sceneIndex]) {
-      scenesIntermediateData[sceneIndex] = {
-        name: String(scene).padStart(2, '0'),
-        groups: {},
-      };
-    }
-
-    // build intermediate scenes data
-    // will be used to resolve patterns later using sceneMetadata
-    scenesIntermediateData[sceneIndex] = {
-      ...scenesIntermediateData[sceneIndex],
-      groups: {
-        ...scenesIntermediateData[sceneIndex].groups,
-        [group]: parsePatternEvents(file.data, sku === SKU_EP40 ? 6 : 4), // EP-40 has 6-byte header
       },
+      timeSignature: defaultScenesSettings.timeSignature,
+    }));
+  }
+
+  const scenes = sceneRecords.map((sceneRecord) => buildScene(sceneRecord, groupPatternLookup));
+  const scenesSettings = {
+    timeSignature: scenes[0]?.timeSignature ?? defaultScenesSettings.timeSignature,
   };
-  }
 
-  Object.entries(scenesIntermediateData).forEach(([sceneIndex, sceneData]) => {
+  return {
-    if (!scenePatternUsage[sceneIndex]) {
+    groupPatterns,
-      return;
+    scenes,
-    }
+    songPositions: scenesFile?.data ? collectSongPositions(scenesFile.data) : [],
-
+    scenesSettings,
-    const patterns = getPatternsForScene(scenesIntermediateData, scenePatternUsage[sceneIndex]);
-    if (patterns.length === 0) {
-      return;
-    }
-
-    scenes[sceneIndex] = {
-      name: sceneData.name,
-      patterns,
-      patternEvents: getPatternEventsForScene(
-        scenesIntermediateData,
-        scenePatternUsage[sceneIndex],
-      ),
   };
-  });
+}
 
-  return Object.values(scenes).sort((a, b) => a.name.localeCompare(b.name));
+export function collectScenesAndPatterns(files: TarFile[], sku: string) {
+  return collectProjectStructure(files, sku).scenes;
 }
 
 export function collectSettings(files: TarFile[]): ProjectSettings {