// List of uneven number of response times.
def responseTimes = [201, 200, 179, 211, 350]

// Get the median from the list of response times.
// As the list has an uneven number of items
// the median is in the middle of the list after
// it has been sorted.
assert GQ {
    from time in responseTimes
    select median(time)
}.toList() == [201]

// List of even number of response times.
responseTimes = [201, 200, 179, 211, 350, 192]

// 2 numbers are the median so the result
// is the average of the 2 numbers.
assert GQ {
    from time in responseTimes
    select median(time)
}.findResult() == 200.5

// Use the GQ annotation and return a List from the method.
@groovy.ginq.transform.GQ(List)
def medianSize(List<String> values) {
    from s in values
    // We can also use an expression to get the median.
    // Here we take the size of the string values to
    // calculage the median.
    select median(s.size())
}

assert medianSize(["Java", "Clojure", "Groovy", "Kotlin", "Scala"]) == [6]

// Sample data structure where each record
// is structured data (map in this case).
// Could also come from JSON for example.
def data = [
    [test: "test1", time: 200],
    [test: "test1", time: 161],
    [test: "test2", time: 427],
    [test: "test2", time: 411],
    [test: "test1", time: 213]
]

// We want to get each record, but also
// the median for all times belonging to a single test.
// We can use the windowing functions provided by GINQ
// together with median.
def query = GQ {
    from result in data
    orderby result.test
    select result.test as test_name,
           result.time as response_time,
           (median(result.time) over(partitionby result.test)) as median_per_test
}

assert query
        .collect { row -> [name: row.test_name,
                           response: row.response_time,
                           median: row.median_per_test] } ==
[
    [name: "test1", response: 200, median: 200],
    [name: "test1", response: 161, median: 200],
    [name: "test1", response: 213, median: 200],
    [name: "test2", response: 427, median: 419],
    [name: "test2", response: 411, median: 419]
]