Ai slop

frontend/app/composables/useVarSliders.ts

@@ -0,0 +1,119 @@
+/* The free-variable sliders both calculators wear: one value per variable
+   in a scope the compile pass reads, one slider per variable anchored under
+   the row that claims it — the row declaring it ("k", "k = 2") when one
+   asks, else the first row speaking it — and the values kept between visits
+   per calculator. A name the scope does not carry yet reads as 1, where
+   every slider starts. */
+
+export interface VarSlider {
+  name: string
+  value: number
+  min: number
+  max: number
+}
+
+/* one row's reading, as far as sliders care: the variables it speaks and
+   the declaration its text claims (a null start says "k", not "k = 2") */
+export interface RowVarDecls {
+  rowId: number
+  vars: string[]
+  declared: { name: string; value: number | null } | null
+}
+
+/* how far a slider reaches either side of zero; a value set past an end —
+   by "k = 40" or by typing — pulls that end out so the thumb can reach it */
+const SLIDER_MIN = -10
+const SLIDER_MAX = 10
+
+export function useVarSliders(
+  varValues: Record<string, number>,
+  decls: () => RowVarDecls[],
+  storageKey: string,
+) {
+  /* every variable spoken, with the value its "k = 2" row asks to start at
+     — or 1, where sliders start. One variable wears one slider however many
+     rows speak it. */
+  const varStarts = computed(() => {
+    const starts = new Map<string, number>()
+    for (const d of decls()) {
+      if (d.declared && !starts.has(d.declared.name)) starts.set(d.declared.name, d.declared.value ?? 1)
+      for (const name of d.vars) if (!starts.has(name)) starts.set(name, 1)
+    }
+    return starts
+  })
+
+  // a variable the rows only now started speaking takes its start value;
+  // one the reader already moved keeps the value they left it at. Filling
+  // from the first pass keeps what the server draws and what the reader
+  // finds after mounting the same
+  function fillDefaults() {
+    for (const [name, value] of varStarts.value) {
+      if (!(name in varValues)) varValues[name] = value
+    }
+  }
+  watch(varStarts, fillDefaults, { immediate: true })
+
+  /* one slider per variable, filed under the row it sits beneath: the row
+     claiming it ("k", "k = 2") wins, else the first row that speaks it */
+  const slidersByRow = computed(() => {
+    const anchor = new Map<string, number>()
+    for (const d of decls()) {
+      if (d.declared && !anchor.has(d.declared.name)) anchor.set(d.declared.name, d.rowId)
+    }
+    for (const d of decls()) {
+      for (const name of d.vars) {
+        if (!anchor.has(name)) anchor.set(name, d.rowId)
+      }
+    }
+    const byRow = new Map<number, VarSlider[]>()
+    for (const d of decls()) {
+      for (const name of d.vars) {
+        if (anchor.get(name) !== d.rowId) continue
+        const value = varValues[name] ?? 1
+        const list = byRow.get(d.rowId) ?? []
+        list.push({ name, value, min: Math.min(SLIDER_MIN, value), max: Math.max(SLIDER_MAX, value) })
+        byRow.set(d.rowId, list)
+      }
+    }
+    return byRow
+  })
+
+  function setVar(name: string, raw: number) {
+    if (Number.isFinite(raw)) varValues[name] = raw
+  }
+
+  /* the values keep themselves — only the ones a row still speaks, so a
+     variable nobody asks for anymore is forgotten on the next save rather
+     than haunting the store */
+  function save() {
+    try {
+      const kept: Record<string, number> = {}
+      for (const [name, value] of Object.entries(varValues)) {
+        if (varStarts.value.has(name) && Number.isFinite(value)) kept[name] = value
+      }
+      localStorage.setItem(storageKey, JSON.stringify(kept))
+    } catch {
+      /* private mode etc. — the slider values just won't persist */
+    }
+  }
+  watch([varValues, varStarts], save)
+
+  onMounted(() => {
+    try {
+      const raw = localStorage.getItem(storageKey)
+      if (raw) {
+        const stored: unknown = JSON.parse(raw)
+        if (typeof stored === 'object' && stored !== null) {
+          for (const [name, value] of Object.entries(stored)) {
+            if (typeof value === 'number' && Number.isFinite(value)) varValues[name] = value
+          }
+        }
+      }
+    } catch {
+      /* storage unreadable — the sliders start where their rows ask */
+    }
+    fillDefaults()
+  })
+
+  return { slidersByRow, setVar }
+}