package system

import (
	"fmt"
	"runtime"
	"testing"

	"github.com/influxdata/telegraf/testutil"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestProcesses(t *testing.T) {
	processes := &Processes{
		execPS:       execPS,
		readProcFile: readProcFile,
	}
	var acc testutil.Accumulator

	err := processes.Gather(&acc)
	require.NoError(t, err)

	assert.True(t, acc.HasInt64Field("processes", "running"))
	assert.True(t, acc.HasInt64Field("processes", "sleeping"))
	assert.True(t, acc.HasInt64Field("processes", "stopped"))
	assert.True(t, acc.HasInt64Field("processes", "total"))
	total, ok := acc.Get("processes")
	require.True(t, ok)
	assert.True(t, total.Fields["total"].(int64) > 0)
}

func TestFromPS(t *testing.T) {
	processes := &Processes{
		execPS:  testExecPS,
		forcePS: true,
	}

	var acc testutil.Accumulator
	err := processes.Gather(&acc)
	require.NoError(t, err)

	fields := getEmptyFields()
	fields["blocked"] = int64(4)
	fields["zombies"] = int64(1)
	fields["running"] = int64(4)
	fields["sleeping"] = int64(34)
	fields["total"] = int64(43)

	acc.AssertContainsTaggedFields(t, "processes", fields, map[string]string{})
}

func TestFromPSError(t *testing.T) {
	processes := &Processes{
		execPS:  testExecPSError,
		forcePS: true,
	}

	var acc testutil.Accumulator
	err := processes.Gather(&acc)
	require.Error(t, err)
}

func TestFromProcFiles(t *testing.T) {
	if runtime.GOOS != "linux" {
		t.Skip("This test only runs on linux")
	}
	tester := tester{}
	processes := &Processes{
		readProcFile: tester.testProcFile,
		forceProc:    true,
	}

	var acc testutil.Accumulator
	err := processes.Gather(&acc)
	require.NoError(t, err)

	fields := getEmptyFields()
	fields["sleeping"] = tester.calls
	fields["total_threads"] = tester.calls * 2
	fields["total"] = tester.calls

	acc.AssertContainsTaggedFields(t, "processes", fields, map[string]string{})
}

func TestFromProcFilesWithSpaceInCmd(t *testing.T) {
	if runtime.GOOS != "linux" {
		t.Skip("This test only runs on linux")
	}
	tester := tester{}
	processes := &Processes{
		readProcFile: tester.testProcFile2,
		forceProc:    true,
	}

	var acc testutil.Accumulator
	err := processes.Gather(&acc)
	require.NoError(t, err)

	fields := getEmptyFields()
	fields["sleeping"] = tester.calls
	fields["total_threads"] = tester.calls * 2
	fields["total"] = tester.calls

	acc.AssertContainsTaggedFields(t, "processes", fields, map[string]string{})
}

func testExecPS() ([]byte, error) {
	return []byte(testPSOut), nil
}

// struct for counting calls to testProcFile
type tester struct {
	calls int64
}

func (t *tester) testProcFile(_ string) ([]byte, error) {
	t.calls++
	return []byte(fmt.Sprintf(testProcStat, "S", "2")), nil
}

func (t *tester) testProcFile2(_ string) ([]byte, error) {
	t.calls++
	return []byte(fmt.Sprintf(testProcStat2, "S", "2")), nil
}

func testExecPSError() ([]byte, error) {
	return []byte(testPSOut), fmt.Errorf("ERROR!")
}

const testPSOut = `
STAT
S
S
S
S
R
R
S
S
Ss
Ss
S
SNs
Ss
Ss
S
R+
S
U
S
S
S
S
Ss
S+
Ss
S
S+
S+
Ss
S+
Ss
S
R+
Ss
S
S+
S+
Ss
L
U
Z
D
S+
`

const testProcStat = `10 (rcuob/0) %s 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 20 0 %s 0 11 0 0 18446744073709551615 0 0 0 0 0 0 0 2147483647 0 18446744073709551615 0 0 17 0 0 0 0 0 0 0 0 0 0 0 0 0 0
`

const testProcStat2 = `10 (rcuob 0) %s 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 20 0 %s 0 11 0 0 18446744073709551615 0 0 0 0 0 0 0 2147483647 0 18446744073709551615 0 0 17 0 0 0 0 0 0 0 0 0 0 0 0 0 0
`