feat(lora_randomizer): implement dual seed mechanism for batch queue synchronization, fixes #773

- Add execution_seed and next_seed parameters to support deterministic randomization across batch executions
- Separate UI display generation from execution stack generation to maintain consistency in batch queues
- Update LoraService to accept optional seed parameter for reproducible randomization
- Ensure each execution with a different seed produces unique results without affecting global random state

vue-widgets/src/components/LoraRandomizerWidget.vue

@@ -54,6 +54,9 @@ const props = defineProps<{
 // State management
 const state = useLoraRandomizerState(props.widget)
 
+// Symbol to track if the widget has been executed at least once
+const HAS_EXECUTED = Symbol('HAS_EXECUTED')
+
 // Track current loras from the loras widget
 const currentLoras = ref<LoraEntry[]>([])
 
@@ -190,6 +193,31 @@ onMounted(async () => {
     state.restoreFromConfig(props.widget.value as RandomizerConfig)
   }
 
+  // Add beforeQueued hook to handle seed shifting for batch queue synchronization
+  // This ensures each execution uses the loras that were displayed before that execution
+  ;(props.widget as any).beforeQueued = () => {
+    // Only process when roll_mode is 'always' (randomize on each execution)
+    if (state.rollMode.value === 'always') {
+      if ((props.widget as any)[HAS_EXECUTED]) {
+        // After first execution: shift seeds (previous next_seed becomes execution_seed)
+        state.generateNewSeed()
+      } else {
+        // First execution: just initialize next_seed (execution_seed stays null)
+        // This means first execution uses loras from widget input
+        state.initializeNextSeed()
+        ;(props.widget as any)[HAS_EXECUTED] = true
+      }
+
+      // Update the widget value so the seeds are included in the serialized config
+      const config = state.buildConfig()
+      if ((props.widget as any).updateConfig) {
+        ;(props.widget as any).updateConfig(config)
+      } else {
+        props.widget.value = config
+      }
+    }
+  }
+
   // Override onExecuted to handle backend UI updates
   const originalOnExecuted = (props.node as any).onExecuted?.bind(props.node)
 

vue-widgets/src/composables/types.ts

@@ -69,6 +69,8 @@ export interface RandomizerConfig {
   use_recommended_strength: boolean
   recommended_strength_scale_min: number
   recommended_strength_scale_max: number
+  execution_seed?: number | null  // Seed for execution_stack (previous next_seed)
+  next_seed?: number | null       // Seed for ui_loras (current)
 }
 
 export interface LoraEntry {

vue-widgets/src/composables/useLoraRandomizerState.ts

@@ -21,6 +21,12 @@ export function useLoraRandomizerState(widget: ComponentWidget) {
   // Track last used combination (for backend roll mode)
   const lastUsed = ref<LoraEntry[] | null>(null)
 
+  // Dual seed mechanism for batch queue synchronization
+  // execution_seed: seed for generating execution_stack (= previous next_seed)
+  // next_seed: seed for generating ui_loras (= what will be displayed after execution)
+  const executionSeed = ref<number | null>(null)
+  const nextSeed = ref<number | null>(null)
+
   // Build config object from current state
   const buildConfig = (): RandomizerConfig => ({
     count_mode: countMode.value,
@@ -37,8 +43,24 @@ export function useLoraRandomizerState(widget: ComponentWidget) {
     use_recommended_strength: useRecommendedStrength.value,
     recommended_strength_scale_min: recommendedStrengthScaleMin.value,
     recommended_strength_scale_max: recommendedStrengthScaleMax.value,
+    execution_seed: executionSeed.value,
+    next_seed: nextSeed.value,
   })
 
+  // Shift seeds for batch queue synchronization
+  // Previous next_seed becomes current execution_seed, and generate a new next_seed
+  const generateNewSeed = () => {
+    executionSeed.value = nextSeed.value  // Previous next becomes current execution
+    nextSeed.value = Math.floor(Math.random() * 2147483647)
+  }
+
+  // Initialize next_seed for first execution (execution_seed stays null)
+  const initializeNextSeed = () => {
+    if (nextSeed.value === null) {
+      nextSeed.value = Math.floor(Math.random() * 2147483647)
+    }
+  }
+
   // Restore state from config object
   const restoreFromConfig = (config: RandomizerConfig) => {
     countMode.value = config.count_mode || 'range'
@@ -185,6 +207,8 @@ export function useLoraRandomizerState(widget: ComponentWidget) {
     useRecommendedStrength,
     recommendedStrengthScaleMin,
     recommendedStrengthScaleMax,
+    executionSeed,
+    nextSeed,
 
     // Computed
     isClipStrengthDisabled,
@@ -195,5 +219,7 @@ export function useLoraRandomizerState(widget: ComponentWidget) {
     restoreFromConfig,
     rollLoras,
     useLastUsed,
+    generateNewSeed,
+    initializeNextSeed,
   }
 }