package process_test

import (
	"fmt"
	"testing"
	"time"

	"github.com/weaveworks/scope/common/mtime"
	"github.com/weaveworks/scope/probe/process"
	"github.com/weaveworks/scope/report"
)

type mockWalker struct {
	processes []process.Process
}

func (m *mockWalker) Walk(f func(process.Process, process.Process)) error {
	for _, p := range m.processes {
		f(p, process.Process{})
	}
	return nil
}

func TestReporter(t *testing.T) {
	processes := []process.Process{
		{PID: 1, PPID: 0, Name: "init"},
		{PID: 2, PPID: 1, Name: "bash"},
		{PID: 3, PPID: 1, Name: "apache", Threads: 2},
		{PID: 4, PPID: 2, Name: "ping", Cmdline: "ping foo.bar.local"},
		{PID: 5, PPID: 1, Cmdline: "tail -f /var/log/syslog"},
	}
	walker := &mockWalker{processes: processes}
	getDeltaTotalJiffies := func() (uint64, float64, error) { return 0, 0., nil }
	now := time.Now()
	mtime.NowForce(now)
	defer mtime.NowReset()

	rpt, err := process.NewReporter(walker, "", getDeltaTotalJiffies).Report()
	if err != nil {
		t.Error(err)
	}

	// It reports the init process
	node, ok := rpt.Process.Nodes[report.MakeProcessNodeID("", "1")]
	if !ok {
		t.Errorf("Expected report to include the pid 1 init")
	}
	if name, ok := node.Latest.Lookup(process.Name); !ok || name != processes[0].Name {
		t.Errorf("Expected %q got %q", processes[0].Name, name)
	}

	// It reports plain processes (with parent pid, and metrics)
	node, ok = rpt.Process.Nodes[report.MakeProcessNodeID("", "2")]
	if !ok {
		t.Errorf("Expected report to include the pid 2 bash")
	}
	if name, ok := node.Latest.Lookup(process.Name); !ok || name != processes[1].Name {
		t.Errorf("Expected %q got %q", processes[1].Name, name)
	}
	if ppid, ok := node.Latest.Lookup(process.PPID); !ok || ppid != fmt.Sprint(processes[1].PPID) {
		t.Errorf("Expected %d got %q", processes[1].PPID, ppid)
	}
	if memoryUsage, ok := node.Metrics[process.MemoryUsage]; !ok {
		t.Errorf("Expected memory usage metric, but not found")
	} else if sample := memoryUsage.LastSample(); sample == nil {
		t.Errorf("Expected memory usage metric to have a sample, but there were none")
	} else if sample.Value != 0. {
		t.Errorf("Expected memory usage metric sample %f, got %f", 0., sample.Value)
	}

	// It reports thread-counts
	node, ok = rpt.Process.Nodes[report.MakeProcessNodeID("", "3")]
	if !ok {
		t.Errorf("Expected report to include the pid 3 apache")
	}
	if threads, ok := node.Latest.Lookup(process.Threads); !ok || threads != fmt.Sprint(processes[2].Threads) {
		t.Errorf("Expected %d got %q", processes[2].Threads, threads)
	}

	// It reports the Cmdline
	node, ok = rpt.Process.Nodes[report.MakeProcessNodeID("", "4")]
	if !ok {
		t.Errorf("Expected report to include the pid 4 ping")
	}
	if cmdline, ok := node.Latest.Lookup(process.Cmdline); !ok || cmdline != fmt.Sprint(processes[3].Cmdline) {
		t.Errorf("Expected %q got %q", processes[3].Cmdline, cmdline)
	}

	// It reports processes without a Name
	node, ok = rpt.Process.Nodes[report.MakeProcessNodeID("", "5")]
	if !ok {
		t.Errorf("Expected report to include the pid 5 tail")
	}
	if name, ok := node.Latest.Lookup(process.Name); ok {
		t.Errorf("Expected no name, but got %q", name)
	}
	if cmdline, ok := node.Latest.Lookup(process.Cmdline); !ok || cmdline != fmt.Sprint(processes[4].Cmdline) {
		t.Errorf("Expected %q got %q", processes[4].Cmdline, cmdline)
	}
}