From 4489fff0022430131ebfc6dc0499e9cdf0464aff Mon Sep 17 00:00:00 2001
From: Volker Krause <vkrause@kde.org>
Date: Sat, 5 Jan 2019 16:45:02 +0100
Subject: [PATCH] Merge journey results from multiple sources

---
 src/publictransport/datatypes/journey.cpp | 59 +++++++++++++++++++++++
 src/publictransport/datatypes/journey.h   | 17 +++++++
 src/publictransport/journeyreply.cpp      | 19 ++++++++
 3 files changed, 95 insertions(+)

diff --git a/src/publictransport/datatypes/journey.cpp b/src/publictransport/datatypes/journey.cpp
index de0a27b..75b48ec 100644
--- a/src/publictransport/datatypes/journey.cpp
+++ b/src/publictransport/datatypes/journey.cpp
@@ -234,6 +234,39 @@ bool JourneySection::arrivalPlatformChanged() const
     return hasExpectedArrivalPlatform() && d->scheduledArrivalPlatform != d->expectedArrivalPlatform;
 }
 
+bool JourneySection::isSame(const JourneySection &lhs, const JourneySection &rhs)
+{
+    return lhs.d->mode == rhs.d->mode
+        && lhs.d->scheduledDepartureTime == rhs.d->scheduledDepartureTime
+        && lhs.d->scheduledArrivalTime == rhs.d->scheduledArrivalTime
+        && Location::isSame(lhs.d->from, rhs.d->from)
+        && Location::isSame(lhs.d->to, rhs.d->to)
+        && Route::isSame(lhs.d->route, rhs.d->route);
+        // ### platforms relevant?
+}
+
+JourneySection JourneySection::merge(const JourneySection &lhs, const JourneySection &rhs)
+{
+    auto res = lhs;
+    if (!res.expectedDepartureTime().isValid()) {
+        res.setExpectedDepartureTime(rhs.expectedDepartureTime());
+    }
+    if (res.expectedDeparturePlatform().isEmpty()) {
+        res.setExpectedDeparturePlatform(rhs.expectedDeparturePlatform());
+    }
+    if (!res.expectedArrivalTime().isValid()) {
+        res.setExpectedArrivalTime(rhs.expectedArrivalTime());
+    }
+    if (res.expectedArrivalPlatform().isEmpty()) {
+        res.setExpectedArrivalPlatform(rhs.expectedArrivalPlatform());
+    }
+    res.setFrom(Location::merge(lhs.from(), rhs.from()));
+    res.setTo(Location::merge(lhs.to(), rhs.to()));
+    res.setRoute(Route::merge(lhs.route(), rhs.route()));
+
+    return res;
+}
+
 
 KPUBLICTRANSPORT_MAKE_GADGET(Journey)
 
@@ -287,4 +320,30 @@ int Journey::numberOfChanges() const
     return std::count_if(d->sections.begin(), d->sections.end(), [](const auto &section) { return section.mode() == JourneySection::PublicTransport; });
 }
 
+bool Journey::isSame(const Journey &lhs, const Journey &rhs)
+{
+    // ### we can make this more clever by ignoring transit elements for example
+    // doing that will need changes below too!
+    if (lhs.sections().size() != rhs.sections().size()) {
+        return false;
+    }
+    return std::equal(lhs.sections().begin(), lhs.sections().end(), rhs.sections().begin(), [](const auto &lhs, const auto &rhs) {
+        return JourneySection::isSame(lhs, rhs);
+    });
+}
+
+Journey Journey::merge(const Journey &lhs, const Journey &rhs)
+{
+    // ### see above
+    std::vector<JourneySection> sections;
+    sections.reserve(lhs.sections().size());
+    for (auto lit = lhs.sections().begin(), rit = rhs.sections().begin(); lit != lhs.sections().end(); ++lit, ++rit) {
+        sections.push_back(JourneySection::merge(*lit, *rit));
+    }
+
+    Journey res;
+    res.setSections(std::move(sections));
+    return res;
+}
+
 #include "moc_journey.cpp"
diff --git a/src/publictransport/datatypes/journey.h b/src/publictransport/datatypes/journey.h
index 9706f79..c7560ae 100644
--- a/src/publictransport/datatypes/journey.h
+++ b/src/publictransport/datatypes/journey.h
@@ -136,6 +136,14 @@ public:
     void setExpectedArrivalPlatform(const QString &platform);
     bool hasExpectedArrivalPlatform() const;
     bool arrivalPlatformChanged() const;
+
+    /** Checks if two instances refer to the same journey section (which does not necessarily mean they are exactly equal). */
+    static bool isSame(const JourneySection &lhs, const JourneySection &rhs);
+
+    /** Merge two instances.
+     *  This assumes isSame(lhs, rhs) and tries to preserve the most detailed information.
+     */
+    static JourneySection merge(const JourneySection &lhs, const JourneySection &rhs);
 };
 
 class JourneyPrivate;
@@ -167,6 +175,15 @@ public:
     QDateTime scheduledArrivalTime() const;
     int duration() const;
     int numberOfChanges() const;
+
+    /** Checks if two instances refer to the same journey (which does not necessarily mean they are exactly equal). */
+    static bool isSame(const Journey &lhs, const Journey &rhs);
+
+    /** Merge two instances.
+     *  This assumes isSame(lhs, rhs) and tries to preserve the most detailed information.
+     */
+    static Journey merge(const Journey &lhs, const Journey &rhs);
+
 private:
     QVariantList sectionsVariant() const;
 };
diff --git a/src/publictransport/journeyreply.cpp b/src/publictransport/journeyreply.cpp
index 5ceadac..377c2fc 100644
--- a/src/publictransport/journeyreply.cpp
+++ b/src/publictransport/journeyreply.cpp
@@ -81,6 +81,25 @@ void JourneyReplyPrivate::postProcessJourneys()
         }
         journey.setSections(std::move(sections));
     }
+
+    // sort and merge results
+    std::sort(journeys.begin(), journeys.end(), [](const auto &lhs, const auto &rhs) {
+        return lhs.scheduledDepartureTime() < rhs.scheduledDepartureTime();
+    });
+    for (auto it = journeys.begin(); it != journeys.end(); ++it) {
+        for (auto mergeIt = it + 1; mergeIt != journeys.end();) {
+            if ((*it).scheduledDepartureTime() != (*mergeIt).scheduledDepartureTime()) {
+                break;
+            }
+
+            if (Journey::isSame(*it, *mergeIt)) {
+                *it = Journey::merge(*it, *mergeIt);
+                mergeIt = journeys.erase(mergeIt);
+            } else {
+                ++mergeIt;
+            }
+        }
+    }
 }
 
 JourneyReply::JourneyReply(const JourneyRequest &req)
-- 
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