1 files changed, 168 insertions, 0 deletions
diff --git a/src/services/theme_data/iss_utils.js b/src/services/theme_data/iss_utils.js
new file mode 100644
index 00000000..75f8dd93
--- /dev/null
+++ b/src/services/theme_data/iss_utils.js
@@ -0,0 +1,168 @@
+import { sortBy } from 'lodash'
+
+// "Unrolls" a tree structure of item: { parent: { ...item2, parent: { ...item3, parent: {...} } }}
+// into an array [item2, item3] for iterating
+export const unroll = (item) => {
+  const out = []
+  let currentParent = item
+  while (currentParent) {
+    out.push(currentParent)
+    currentParent = currentParent.parent
+  }
+  return out
+}
+
+// This gives you an array of arrays of all possible unique (i.e. order-insensitive) combinations
+// Can only accept primitives. Duplicates are not supported and can cause unexpected behavior
+export const getAllPossibleCombinations = (array) => {
+  const combos = [array.map(x => [x])]
+  for (let comboSize = 2; comboSize <= array.length; comboSize++) {
+    const previous = combos[combos.length - 1]
+    const newCombos = previous.map(self => {
+      const selfSet = new Set()
+      self.forEach(x => selfSet.add(x))
+      const nonSelf = array.filter(x => !selfSet.has(x))
+      return nonSelf.map(x => [...self, x])
+    })
+    const flatCombos = newCombos.reduce((acc, x) => [...acc, ...x], [])
+    const uniqueComboStrings = new Set()
+    const uniqueCombos = flatCombos.map(sortBy).filter(x => {
+      if (uniqueComboStrings.has(x.join())) {
+        return false
+      } else {
+        uniqueComboStrings.add(x.join())
+        return true
+      }
+    })
+    combos.push(uniqueCombos)
+  }
+  return combos.reduce((acc, x) => [...acc, ...x], [])
+}
+
+/**
+ * Converts rule, parents and their criteria into a CSS (or path if ignoreOutOfTreeSelector == true)
+ * selector.
+ *
+ * "path" here refers to "fake" selector that cannot be actually used in UI but is used for internal
+ * purposes
+ *
+ * @param {Object} components - object containing all components definitions
+ *
+ * @returns {Function}
+ * @param {Object} rule - rule in question to convert to CSS selector
+ * @param {boolean} ignoreOutOfTreeSelector - wthether to ignore aformentioned field in
+ *   component definition and use selector
+ * @param {boolean} isParent - (mostly) internal argument used when recursing
+ *
+ * @returns {String} CSS selector (or path)
+ */
+export const genericRuleToSelector = components => (rule, ignoreOutOfTreeSelector, isParent) => {
+  if (!rule && !isParent) return null
+  const component = components[rule.component]
+  const { states = {}, variants = {}, selector, outOfTreeSelector } = component
+
+  const applicableStates = ((rule.state || []).filter(x => x !== 'normal')).map(state => states[state])
+
+  const applicableVariantName = (rule.variant || 'normal')
+  let applicableVariant = ''
+  if (applicableVariantName !== 'normal') {
+    applicableVariant = variants[applicableVariantName]
+  } else {
+    applicableVariant = variants?.normal ?? ''
+  }
+
+  let realSelector
+  if (selector === ':root') {
+    realSelector = ''
+  } else if (isParent) {
+    realSelector = selector
+  } else {
+    if (outOfTreeSelector && !ignoreOutOfTreeSelector) realSelector = outOfTreeSelector
+    else realSelector = selector
+  }
+
+  const selectors = [realSelector, applicableVariant, ...applicableStates]
+    .sort((a, b) => {
+      if (a.startsWith(':')) return 1
+      if (/^[a-z]/.exec(a)) return -1
+      else return 0
+    })
+    .join('')
+
+  if (rule.parent) {
+    return (genericRuleToSelector(components)(rule.parent, ignoreOutOfTreeSelector, true) + ' ' + selectors).trim()
+  }
+  return selectors.trim()
+}
+
+/**
+ * Check if combination matches
+ *
+ * @param {Object} criteria - criteria to match against
+ * @param {Object} subject - rule/combination to check match
+ * @param {boolean} strict - strict checking:
+ *   By default every variant and state inherits from "normal" state/variant
+ *   so when checking if combination matches, it WILL match against "normal"
+ *   state/variant. In strict mode inheritance is ignored an "normal" does
+ *   not match
+ */
+export const combinationsMatch = (criteria, subject, strict) => {
+  if (criteria.component !== subject.component) return false
+
+  // All variants inherit from normal
+  if (subject.variant !== 'normal' || strict) {
+    if (criteria.variant !== subject.variant) return false
+  }
+
+  // Subject states > 1 essentially means state is "normal" and therefore matches
+  if (subject.state.length > 1 || strict) {
+    const subjectStatesSet = new Set(subject.state)
+    const criteriaStatesSet = new Set(criteria.state)
+
+    const setsAreEqual =
+      [...criteriaStatesSet].every(state => subjectStatesSet.has(state)) &&
+      [...subjectStatesSet].every(state => criteriaStatesSet.has(state))
+
+    if (!setsAreEqual) return false
+  }
+  return true
+}
+
+/**
+ * Search for rule that matches `criteria` in set of rules
+ * meant to be used in a ruleset.filter() function
+ *
+ * @param {Object} criteria - criteria to search for
+ * @param {boolean} strict - whether search strictly or not (see combinationsMatch)
+ *
+ * @return function that returns true/false if subject matches
+ */
+export const findRules = (criteria, strict) => subject => {
+  // If we searching for "general" rules - ignore "specific" ones
+  if (criteria.parent === null && !!subject.parent) return false
+  if (!combinationsMatch(criteria, subject, strict)) return false
+
+  if (criteria.parent !== undefined && criteria.parent !== null) {
+    if (!subject.parent && !strict) return true
+    const pathCriteria = unroll(criteria)
+    const pathSubject = unroll(subject)
+    if (pathCriteria.length < pathSubject.length) return false
+
+    // Search: .a .b .c
+    // Matches: .a .b .c; .b .c; .c; .z .a .b .c
+    // Does not match .a .b .c .d, .a .b .e
+    for (let i = 0; i < pathCriteria.length; i++) {
+      const criteriaParent = pathCriteria[i]
+      const subjectParent = pathSubject[i]
+      if (!subjectParent) return true
+      if (!combinationsMatch(criteriaParent, subjectParent, strict)) return false
+    }
+  }
+  return true
+}
+
+// Pre-fills 'normal' state/variant if missing
+export const normalizeCombination = rule => {
+  rule.variant = rule.variant ?? 'normal'
+  rule.state = [...new Set(['normal', ...(rule.state || [])])]
+}