Backporting CleverRaven#51086 In crafting every tool is displayed onl…

…y once

src/requirements.cpp

@@ -49,6 +49,11 @@ static const trait_id trait_DEBUG_HS( "DEBUG_HS" );
 
 static std::map<requirement_id, requirement_data> requirements_all;
 
+static bool a_satisfies_b( const quality_requirement &a, const quality_requirement &b );
+static bool a_satisfies_b( const std::vector<quality_requirement> &a,
+                           const std::vector<quality_requirement> &b );
+
+
 /** @relates string_id */
 template<>
 bool string_id<requirement_data>::is_valid() const
@@ -317,18 +322,75 @@ requirement_data requirement_data::operator*( unsigned scalar ) const
     return res;
 }
 
+static bool a_satisfies_b( const quality_requirement &a, const quality_requirement &b )
+{
+    return a.type == b.type && a.level >= b.level
+           && a.requirement == b.requirement && a.count == b.count;
+}
+
+static bool a_satisfies_b( const std::vector<quality_requirement> &a,
+                           const std::vector<quality_requirement> &b )
+{
+    // every b_x is satisfied by some a_x
+    for( const quality_requirement &b_x : b ) {
+        bool satisfied = false;
+        for( const quality_requirement &a_x : a ) {
+            if( a_satisfies_b( a_x, b_x ) ) {
+                satisfied = true;
+                break;
+            }
+        }
+        if( !satisfied ) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
 requirement_data requirement_data::operator+( const requirement_data &rhs ) const
 {
     requirement_data res = *this;
 
     res.components.insert( res.components.end(), rhs.components.begin(), rhs.components.end() );
     res.tools.insert( res.tools.end(), rhs.tools.begin(), rhs.tools.end() );
-    res.qualities.insert( res.qualities.end(), rhs.qualities.begin(), rhs.qualities.end() );
+    /*
+    TODO: what is / isn't implemented:
+    I will represent type by letter and level by number, always true: count = 1 && requirement = false
+    A1 then has type A with level 1, (count = 1, requirement = false)
+    X) [implemented ? "x" else " "] What's required -> How should it be displayed
+    1) [x] A1 && A1 -> A1
+    2) [x] A1 && A2 -> A2
+    3) [x] (A1 || B1) && A1 -> A1
+    4) [ ] A1 || A2 -> A1
+    5) [ ] (A1 || B1) && A2 -> A2
+    6) [ ] (A1 || B1 || C1) || (A1 || B1) -> A1 || B1 || C1
+    Note: (1) covers most cases, (2) probably the rest, (3..6) probably isn't anywhere?
+
+    It all takes O(n^2), but that's acceptable since n is very small.
+    @Brambor
+    */
+    for( const std::vector<quality_requirement> &new_quality : rhs.qualities ) {
+        bool add = true;
+        for( std::vector<quality_requirement> &old_quality : res.qualities ) {
+            if( a_satisfies_b( new_quality, old_quality ) ) {
+                add = false;
+                old_quality = new_quality;
+                break;
+            } else if( a_satisfies_b( old_quality, new_quality ) ) {
+                add = false;
+                break;
+            }
+        }
+        if( add ) {
+            res.qualities.emplace_back( new_quality );
+        }
+    }
 
     // combined result is temporary which caller could store via @ref save_requirement
     res.id_ = requirement_id::NULL_ID();
 
-    // TODO: deduplicate qualities and combine other requirements
+    // TODO: combine other requirements
 
     // if either operand was blacklisted then their summation should also be
     res.blacklisted |= rhs.blacklisted;