package fs

import (
	"testing"

	"github.com/docker/libcontainer/cgroups"
)

const (
	sectorsRecursiveContents      = `8:0 1024`
	serviceBytesRecursiveContents = `8:0 Read 100
8:0 Write 200
8:0 Sync 300
8:0 Async 500
8:0 Total 500
Total 500`
	servicedRecursiveContents = `8:0 Read 10
8:0 Write 40
8:0 Sync 20
8:0 Async 30
8:0 Total 50
Total 50`
	queuedRecursiveContents = `8:0 Read 1
8:0 Write 4
8:0 Sync 2
8:0 Async 3
8:0 Total 5
Total 5`
)

var actualStats = *cgroups.NewStats()

func appendBlkioStatEntry(blkioStatEntries *[]cgroups.BlkioStatEntry, major, minor, value uint64, op string) {
	*blkioStatEntries = append(*blkioStatEntries, cgroups.BlkioStatEntry{Major: major, Minor: minor, Value: value, Op: op})
}

func TestBlkioStats(t *testing.T) {
	helper := NewCgroupTestUtil("blkio", t)
	defer helper.cleanup()
	helper.writeFileContents(map[string]string{
		"blkio.io_service_bytes_recursive": serviceBytesRecursiveContents,
		"blkio.io_serviced_recursive":      servicedRecursiveContents,
		"blkio.io_queued_recursive":        queuedRecursiveContents,
		"blkio.sectors_recursive":          sectorsRecursiveContents,
	})

	blkio := &blkioGroup{}
	err := blkio.GetStats(helper.CgroupData, &actualStats)
	if err != nil {
		t.Fatal(err)
	}

	// Verify expected stats.
	expectedStats := cgroups.BlkioStats{}
	appendBlkioStatEntry(&expectedStats.SectorsRecursive, 8, 0, 1024, "")

	appendBlkioStatEntry(&expectedStats.IoServiceBytesRecursive, 8, 0, 100, "Read")
	appendBlkioStatEntry(&expectedStats.IoServiceBytesRecursive, 8, 0, 200, "Write")
	appendBlkioStatEntry(&expectedStats.IoServiceBytesRecursive, 8, 0, 300, "Sync")
	appendBlkioStatEntry(&expectedStats.IoServiceBytesRecursive, 8, 0, 500, "Async")
	appendBlkioStatEntry(&expectedStats.IoServiceBytesRecursive, 8, 0, 500, "Total")

	appendBlkioStatEntry(&expectedStats.IoServicedRecursive, 8, 0, 10, "Read")
	appendBlkioStatEntry(&expectedStats.IoServicedRecursive, 8, 0, 40, "Write")
	appendBlkioStatEntry(&expectedStats.IoServicedRecursive, 8, 0, 20, "Sync")
	appendBlkioStatEntry(&expectedStats.IoServicedRecursive, 8, 0, 30, "Async")
	appendBlkioStatEntry(&expectedStats.IoServicedRecursive, 8, 0, 50, "Total")

	appendBlkioStatEntry(&expectedStats.IoQueuedRecursive, 8, 0, 1, "Read")
	appendBlkioStatEntry(&expectedStats.IoQueuedRecursive, 8, 0, 4, "Write")
	appendBlkioStatEntry(&expectedStats.IoQueuedRecursive, 8, 0, 2, "Sync")
	appendBlkioStatEntry(&expectedStats.IoQueuedRecursive, 8, 0, 3, "Async")
	appendBlkioStatEntry(&expectedStats.IoQueuedRecursive, 8, 0, 5, "Total")

	expectBlkioStatsEquals(t, expectedStats, actualStats.BlkioStats)
}

func TestBlkioStatsNoSectorsFile(t *testing.T) {
	helper := NewCgroupTestUtil("blkio", t)
	defer helper.cleanup()
	helper.writeFileContents(map[string]string{
		"blkio.io_service_bytes_recursive": serviceBytesRecursiveContents,
		"blkio.io_serviced_recursive":      servicedRecursiveContents,
		"blkio.io_queued_recursive":        queuedRecursiveContents,
	})

	blkio := &blkioGroup{}
	err := blkio.GetStats(helper.CgroupData, &actualStats)
	if err == nil {
		t.Fatal("Expected to fail, but did not")
	}
}

func TestBlkioStatsNoServiceBytesFile(t *testing.T) {
	helper := NewCgroupTestUtil("blkio", t)
	defer helper.cleanup()
	helper.writeFileContents(map[string]string{
		"blkio.io_serviced_recursive": servicedRecursiveContents,
		"blkio.io_queued_recursive":   queuedRecursiveContents,
		"blkio.sectors_recursive":     sectorsRecursiveContents,
	})

	blkio := &blkioGroup{}
	err := blkio.GetStats(helper.CgroupData, &actualStats)
	if err == nil {
		t.Fatal("Expected to fail, but did not")
	}
}

func TestBlkioStatsNoServicedFile(t *testing.T) {
	helper := NewCgroupTestUtil("blkio", t)
	defer helper.cleanup()
	helper.writeFileContents(map[string]string{
		"blkio.io_service_bytes_recursive": serviceBytesRecursiveContents,
		"blkio.io_queued_recursive":        queuedRecursiveContents,
		"blkio.sectors_recursive":          sectorsRecursiveContents,
	})

	blkio := &blkioGroup{}
	err := blkio.GetStats(helper.CgroupData, &actualStats)
	if err == nil {
		t.Fatal("Expected to fail, but did not")
	}
}

func TestBlkioStatsNoQueuedFile(t *testing.T) {
	helper := NewCgroupTestUtil("blkio", t)
	defer helper.cleanup()
	helper.writeFileContents(map[string]string{
		"blkio.io_service_bytes_recursive": serviceBytesRecursiveContents,
		"blkio.io_serviced_recursive":      servicedRecursiveContents,
		"blkio.sectors_recursive":          sectorsRecursiveContents,
	})

	blkio := &blkioGroup{}
	err := blkio.GetStats(helper.CgroupData, &actualStats)
	if err == nil {
		t.Fatal("Expected to fail, but did not")
	}
}

func TestBlkioStatsUnexpectedNumberOfFields(t *testing.T) {
	helper := NewCgroupTestUtil("blkio", t)
	defer helper.cleanup()
	helper.writeFileContents(map[string]string{
		"blkio.io_service_bytes_recursive": "8:0 Read 100 100",
		"blkio.io_serviced_recursive":      servicedRecursiveContents,
		"blkio.io_queued_recursive":        queuedRecursiveContents,
		"blkio.sectors_recursive":          sectorsRecursiveContents,
	})

	blkio := &blkioGroup{}
	err := blkio.GetStats(helper.CgroupData, &actualStats)
	if err == nil {
		t.Fatal("Expected to fail, but did not")
	}
}

func TestBlkioStatsUnexpectedFieldType(t *testing.T) {
	helper := NewCgroupTestUtil("blkio", t)
	defer helper.cleanup()
	helper.writeFileContents(map[string]string{
		"blkio.io_service_bytes_recursive": "8:0 Read Write",
		"blkio.io_serviced_recursive":      servicedRecursiveContents,
		"blkio.io_queued_recursive":        queuedRecursiveContents,
		"blkio.sectors_recursive":          sectorsRecursiveContents,
	})

	blkio := &blkioGroup{}
	err := blkio.GetStats(helper.CgroupData, &actualStats)
	if err == nil {
		t.Fatal("Expected to fail, but did not")
	}
}
