Add --averaged-lot-prices

This joins together lots of the same underlying, averaging the reported price
and using the date of the oldest lot.

4 files changed, 81 insertions, 0 deletions

diff --git a/src/balance.cc b/src/balance.cc
index 5f5e6fc9..f0065dc5 100644
--- a/src/balance.cc
+++ b/src/balance.cc
@@ -345,4 +345,63 @@ void put_balance(property_tree::ptree& st, const balance_t& bal)
     put_amount(st.add("amount", ""), pair.second);
 }
 
+balance_t average_lot_prices(const balance_t& bal)
+{
+  // First, we split the balance into multiple balances by underlying
+  // commodity.
+  typedef std::map<optional<std::string>,
+                   std::pair<amount_t, annotation_t> > balance_map;
+  balance_map bycomm;
+
+  foreach (const balance_t::amounts_map::value_type& pair, bal.amounts) {
+    optional<std::string> sym(pair.first->symbol());
+    amount_t quant(pair.second.strip_annotations(keep_details_t()));
+
+    balance_map::iterator i = bycomm.find(sym);
+    if (i == bycomm.end()) {
+      bycomm.insert(
+        balance_map::value_type(sym, std::make_pair(quant, annotation_t())));
+      i = bycomm.find(sym);    // must succeed now
+    } else {
+      (*i).second.first += quant;
+    }
+
+    if (pair.first->has_annotation()) {
+      annotated_commodity_t& acomm(static_cast<annotated_commodity_t&>(*pair.first));
+      annotation_t& ann((*i).second.second);
+
+      if (acomm.details.price) {
+        if (ann.price)
+          ann.price = *ann.price + (*acomm.details.price * quant);
+        else
+          ann.price = *acomm.details.price * quant;
+      }
+
+      if (acomm.details.date) {
+        if (! ann.date || *acomm.details.date < *ann.date)
+          ann.date = *acomm.details.date;
+      }
+    }
+  }
+
+  balance_t result;
+
+  foreach (balance_map::value_type& pair, bycomm) {
+    amount_t amt(pair.second.first);
+    if (! amt.is_realzero()) {
+      if (pair.second.second.price)
+        pair.second.second.price = *pair.second.second.price / amt;
+
+      commodity_t * acomm =
+        commodity_pool_t::current_pool->find_or_create(
+          amt.commodity(), pair.second.second);
+      amt.set_commodity(*acomm);
+
+      result += amt;
+    }
+  }
+
+  return result;
+}
+
 } // namespace ledger
diff --git a/src/balance.h b/src/balance.h
index bd373cb9..19b6bd84 100644
--- a/src/balance.h
+++ b/src/balance.h
@@ -603,6 +603,8 @@ inline std::ostream& operator<<(std::ostream& out, const balance_t& bal) {
 
 void put_balance(property_tree::ptree& pt, const balance_t& bal);
 
+balance_t average_lot_prices(const balance_t& bal);
+
 } // namespace ledger
 
 #endif // _BALANCE_H
diff --git a/src/report.cc b/src/report.cc
index cc165184..c5d6d14e 100644
--- a/src/report.cc
+++ b/src/report.cc
@@ -563,6 +563,14 @@ value_t report_t::fn_should_bold(call_scope_t& scope)
     return false;
 }
 
+value_t report_t::fn_averaged_lots(call_scope_t& args)
+{
+  if (args.has<balance_t>(0))
+    return average_lot_prices(args.get<balance_t>(0));
+  else
+    return args[0];
+}
+
 value_t report_t::fn_market(call_scope_t& args)
 {
   value_t result;
@@ -1130,6 +1138,7 @@ option_t<report_t> * report_t::lookup_option(const char * p)
     else OPT(average);
     else OPT(account_width_);
     else OPT(amount_width_);
+    else OPT(average_lot_prices);
     break;
   case 'b':
     OPT(balance_format_);
@@ -1370,6 +1379,8 @@ expr_t::ptr_op_t report_t::lookup(const symbol_t::kind_t kind,
         return MAKE_FUNCTOR(report_t::fn_ansify_if);
       else if (is_eq(p, "abs"))
         return MAKE_FUNCTOR(report_t::fn_abs);
+      else if (is_eq(p, "averaged_lots"))
+        return MAKE_FUNCTOR(report_t::fn_averaged_lots);
       break;
 
     case 'b':
diff --git a/src/report.h b/src/report.h
index 7775e21d..5325c3a2 100644
--- a/src/report.h
+++ b/src/report.h
@@ -202,6 +202,7 @@ public:
   value_t fn_to_string(call_scope_t& scope);
   value_t fn_to_mask(call_scope_t& scope);
   value_t fn_to_sequence(call_scope_t& scope);
+  value_t fn_averaged_lots(call_scope_t& scope);
 
   value_t fn_now(call_scope_t&) {
     return terminus;
@@ -298,6 +299,7 @@ public:
     HANDLER(limit_).report(out);
     HANDLER(lot_dates).report(out);
     HANDLER(lot_prices).report(out);
+    HANDLER(average_lot_prices).report(out);
     HANDLER(lot_notes).report(out);
     HANDLER(lots).report(out);
     HANDLER(lots_actual).report(out);
@@ -745,6 +747,13 @@ public:
 
   OPTION(report_t, lot_dates);
   OPTION(report_t, lot_prices);
+  OPTION_(report_t, average_lot_prices, DO() {
+      OTHER(lot_prices).on(whence);
+      OTHER(display_amount_)
+        .on(whence, "averaged_lots(display_amount)");
+      OTHER(display_total_)
+        .on(whence, "averaged_lots(display_total)");
+    });
   OPTION(report_t, lot_notes);
   OPTION(report_t, lots);
   OPTION(report_t, lots_actual);