From 9a855d3c26f25ef15b219f041120883b1945d0db Mon Sep 17 00:00:00 2001
From: vovatrykoz <vovatrykoz@gmail.com>
Date: Fri, 22 Nov 2024 13:58:09 +0100
Subject: [PATCH] can generate task instance chains from a collection of tasks

---
 include/TaskScheduling.h      |  3 ++
 source/TaskScheduling.cpp     | 27 +++++++++++++++-
 tests/TaskSchedulingTests.cpp | 60 +++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+), 1 deletion(-)

diff --git a/include/TaskScheduling.h b/include/TaskScheduling.h
index 2c0961c..8834534 100644
--- a/include/TaskScheduling.h
+++ b/include/TaskScheduling.h
@@ -9,6 +9,9 @@ namespace scheduling {
 
 int calculateLcmForEndToEndPath(const std::vector<Task>& endToEndPath);
 
+std::vector<std::vector<TaskInstance>> generateTaskInstancesFromTasks(
+    const std::vector<Task>& endToEndPath);
+
 }  // namespace scheduling
 
 #endif
\ No newline at end of file
diff --git a/source/TaskScheduling.cpp b/source/TaskScheduling.cpp
index 06e3f89..7124629 100644
--- a/source/TaskScheduling.cpp
+++ b/source/TaskScheduling.cpp
@@ -14,4 +14,29 @@ int scheduling::calculateLcmForEndToEndPath(
     }
 
     return acc;
-}
\ No newline at end of file
+}
+
+std::vector<std::vector<TaskInstance>>
+scheduling::generateTaskInstancesFromTasks(
+    const std::vector<Task>& endToEndPath) {
+    if (endToEndPath.empty()) {
+        return std::vector<std::vector<TaskInstance>>();
+    }
+
+    std::vector<std::vector<TaskInstance>> result(endToEndPath.size());
+    int lcm = scheduling::calculateLcmForEndToEndPath(endToEndPath);
+
+    for (int i = 0; i < endToEndPath.size(); i++) {
+        int instanceCount = lcm / endToEndPath[i].period;
+
+        for (int j = 0; j < instanceCount; j++) {
+            TaskInstance taskInstance(
+                endToEndPath[i],
+                endToEndPath[i].offset + endToEndPath[i].period * j);
+
+            result[i].push_back(taskInstance);
+        }
+    }
+
+    return result;
+}
diff --git a/tests/TaskSchedulingTests.cpp b/tests/TaskSchedulingTests.cpp
index f4bc25d..4eaeb61 100644
--- a/tests/TaskSchedulingTests.cpp
+++ b/tests/TaskSchedulingTests.cpp
@@ -28,5 +28,65 @@ TEST(TaskScheduling, CorrectLcmForSeveralTasks) {
     int expected = 120;
     int actual = scheduling::calculateLcmForEndToEndPath(tasks);
 
+    EXPECT_EQ(expected, actual);
+}
+
+TEST(TaskScheduling, EmptyTaskChainReturnsEmptyTaskInstanceChain) {
+    std::vector<std::vector<TaskInstance>> actual =
+        scheduling::generateTaskInstancesFromTasks({});
+
+    EXPECT_TRUE(actual.empty());
+}
+
+TEST(TaskScheduling,
+     TaskChainReturnsWithOneTaskReturnsSingleTaskInstanceInChain) {
+    Task t1(40, 4, 1);
+
+    std::vector<std::vector<TaskInstance>> expected = {{TaskInstance(t1, 0)}};
+    std::vector<std::vector<TaskInstance>> actual =
+        scheduling::generateTaskInstancesFromTasks({t1});
+
+    EXPECT_EQ(expected, actual);
+}
+
+TEST(TaskScheduling, CorrectInstanceChainsForSeveralTasks) {
+    Task t1(20, 4, 1);
+    Task t2(40, 3, 1);
+    Task t3(4, 2, 1);
+
+    std::vector<Task> tasks = {t1, t2, t3};
+
+    std::vector<std::vector<TaskInstance>> expected = {
+        {TaskInstance(t1, 0), TaskInstance(t1, 20)},
+        {TaskInstance(t2, 0)},
+        {TaskInstance(t3, 0), TaskInstance(t3, 4), TaskInstance(t3, 8),
+         TaskInstance(t3, 12), TaskInstance(t3, 16), TaskInstance(t3, 20),
+         TaskInstance(t3, 24), TaskInstance(t3, 28), TaskInstance(t3, 32),
+         TaskInstance(t3, 36)}};
+
+    std::vector<std::vector<TaskInstance>> actual =
+        scheduling::generateTaskInstancesFromTasks(tasks);
+
+    EXPECT_EQ(expected, actual);
+}
+
+TEST(TaskScheduling, CorrectInstanceChainsForSeveralTasksWithOffsets) {
+    Task t1(20, 4, 1, 2);
+    Task t2(40, 3, 1, 7);
+    Task t3(4, 2, 1, 5);
+
+    std::vector<Task> tasks = {t1, t2, t3};
+
+    std::vector<std::vector<TaskInstance>> expected = {
+        {TaskInstance(t1, 2), TaskInstance(t1, 22)},
+        {TaskInstance(t2, 7)},
+        {TaskInstance(t3, 5), TaskInstance(t3, 9), TaskInstance(t3, 13),
+         TaskInstance(t3, 17), TaskInstance(t3, 21), TaskInstance(t3, 25),
+         TaskInstance(t3, 29), TaskInstance(t3, 33), TaskInstance(t3, 37),
+         TaskInstance(t3, 41)}};
+
+    std::vector<std::vector<TaskInstance>> actual =
+        scheduling::generateTaskInstancesFromTasks(tasks);
+
     EXPECT_EQ(expected, actual);
 }
\ No newline at end of file