package config

import (
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"strings"
	"testing"
	"time"

	"gopkg.in/yaml.v2"

	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmalert/notifier"
	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmalert/templates"
	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promutils"
)

func TestMain(m *testing.M) {
	if err := templates.Load([]string{"testdata/templates/*good.tmpl"}, true); err != nil {
		os.Exit(1)
	}
	os.Exit(m.Run())
}

func TestParseGood(t *testing.T) {
	if _, err := Parse([]string{"testdata/rules/*good.rules", "testdata/dir/*good.*"}, notifier.ValidateTemplates, true); err != nil {
		t.Errorf("error parsing files %s", err)
	}
}

func TestParseFromURL(t *testing.T) {
	mux := http.NewServeMux()
	mux.HandleFunc("/bad", func(w http.ResponseWriter, _ *http.Request) {
		w.Write([]byte("foo bar"))
	})
	mux.HandleFunc("/good-alert", func(w http.ResponseWriter, _ *http.Request) {
		w.Write([]byte(`
groups:
  - name: TestGroup
    rules:
      - alert: Conns
        expr: vm_tcplistener_conns > 0`))
	})
	mux.HandleFunc("/good-rr", func(w http.ResponseWriter, _ *http.Request) {
		w.Write([]byte(`
groups:
  - name: TestGroup
    rules:
      - record: conns
        expr: max(vm_tcplistener_conns)`))
	})

	srv := httptest.NewServer(mux)
	defer srv.Close()

	if _, err := Parse([]string{srv.URL + "/good-alert", srv.URL + "/good-rr"}, notifier.ValidateTemplates, true); err != nil {
		t.Errorf("error parsing URLs %s", err)
	}

	if _, err := Parse([]string{srv.URL + "/bad"}, notifier.ValidateTemplates, true); err == nil {
		t.Errorf("expected parsing error: %s", err)
	}
}

func TestParseBad(t *testing.T) {
	testCases := []struct {
		path   []string
		expErr string
	}{
		{
			[]string{"testdata/rules/rules0-bad.rules"},
			"unexpected token",
		},
		{
			[]string{"testdata/dir/rules0-bad.rules"},
			"error parsing annotation",
		},
		{
			[]string{"testdata/dir/rules1-bad.rules"},
			"duplicate in file",
		},
		{
			[]string{"testdata/dir/rules2-bad.rules"},
			"function \"unknown\" not defined",
		},
		{
			[]string{"testdata/dir/rules3-bad.rules"},
			"either `record` or `alert` must be set",
		},
		{
			[]string{"testdata/dir/rules4-bad.rules"},
			"either `record` or `alert` must be set",
		},
		{
			[]string{"testdata/rules/rules1-bad.rules"},
			"bad graphite expr",
		},
		{
			[]string{"testdata/dir/rules6-bad.rules"},
			"missing ':' in header",
		},
		{
			[]string{"http://unreachable-url"},
			"failed to read",
		},
	}
	for _, tc := range testCases {
		_, err := Parse(tc.path, notifier.ValidateTemplates, true)
		if err == nil {
			t.Errorf("expected to get error")
			return
		}
		if !strings.Contains(err.Error(), tc.expErr) {
			t.Errorf("expected err to contain %q; got %q instead", tc.expErr, err)
		}
	}
}

func TestRule_Validate(t *testing.T) {
	if err := (&Rule{}).Validate(); err == nil {
		t.Errorf("expected empty name error")
	}
	if err := (&Rule{Alert: "alert"}).Validate(); err == nil {
		t.Errorf("expected empty expr error")
	}
	if err := (&Rule{Alert: "alert", Expr: "test>0"}).Validate(); err != nil {
		t.Errorf("expected valid rule; got %s", err)
	}
}

func TestGroup_Validate(t *testing.T) {
	testCases := []struct {
		group               *Group
		rules               []Rule
		validateAnnotations bool
		validateExpressions bool
		expErr              string
	}{
		{
			group:  &Group{},
			expErr: "group name must be set",
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{
						Record: "record",
						Expr:   "up | 0",
					},
				},
			},
			expErr: "",
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{
						Record: "record",
						Expr:   "up | 0",
					},
				},
			},
			expErr:              "invalid expression",
			validateExpressions: true,
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{
						Alert: "alert",
						Expr:  "up == 1",
						Labels: map[string]string{
							"summary": "{{ value|query }}",
						},
					},
				},
			},
			expErr: "",
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{
						Alert: "alert",
						Expr:  "up == 1",
						Labels: map[string]string{
							"summary": `
{{ with printf "node_memory_MemTotal{job='node',instance='%s'}" "localhost" | query }}
  {{ . | first | value | humanize1024 }}B
{{ end }}`,
						},
					},
				},
			},
			validateAnnotations: true,
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{
						Alert: "alert",
						Expr:  "up == 1",
					},
					{
						Alert: "alert",
						Expr:  "up == 1",
					},
				},
			},
			expErr: "duplicate",
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"summary": "{{ value|query }}",
					}},
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"summary": "{{ value|query }}",
					}},
				},
			},
			expErr: "duplicate",
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{Record: "record", Expr: "up == 1", Labels: map[string]string{
						"summary": "{{ value|query }}",
					}},
					{Record: "record", Expr: "up == 1", Labels: map[string]string{
						"summary": "{{ value|query }}",
					}},
				},
			},
			expErr: "duplicate",
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"summary": "{{ value|query }}",
					}},
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"description": "{{ value|query }}",
					}},
				},
			},
			expErr: "",
		},
		{
			group: &Group{
				Name: "test",
				Rules: []Rule{
					{Record: "alert", Expr: "up == 1", Labels: map[string]string{
						"summary": "{{ value|query }}",
					}},
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"summary": "{{ value|query }}",
					}},
				},
			},
			expErr: "",
		},
		{
			group: &Group{
				Name: "test thanos",
				Type: NewRawType("thanos"),
				Rules: []Rule{
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"description": "{{ value|query }}",
					}},
				},
			},
			validateExpressions: true,
			expErr:              "unknown datasource type",
		},
		{
			group: &Group{
				Name: "test graphite",
				Type: NewGraphiteType(),
				Rules: []Rule{
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"description": "some-description",
					}},
				},
			},
			validateExpressions: true,
			expErr:              "",
		},
		{
			group: &Group{
				Name: "test prometheus",
				Type: NewPrometheusType(),
				Rules: []Rule{
					{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
						"description": "{{ value|query }}",
					}},
				},
			},
			validateExpressions: true,
			expErr:              "",
		},
		{
			group: &Group{
				Name: "test graphite inherit",
				Type: NewGraphiteType(),
				Rules: []Rule{
					{
						Expr: "sumSeries(time('foo.bar',10))",
						For:  promutils.NewDuration(10 * time.Millisecond),
					},
					{
						Expr: "sum(up == 0 ) by (host)",
					},
				},
			},
		},
		{
			group: &Group{
				Name: "test graphite prometheus bad expr",
				Type: NewGraphiteType(),
				Rules: []Rule{
					{
						Expr: "sum(up == 0 ) by (host)",
						For:  promutils.NewDuration(10 * time.Millisecond),
					},
					{
						Expr: "sumSeries(time('foo.bar',10))",
					},
				},
			},
			expErr: "invalid rule",
		},
	}

	for _, tc := range testCases {
		var validateTplFn ValidateTplFn
		if tc.validateAnnotations {
			validateTplFn = notifier.ValidateTemplates
		}
		err := tc.group.Validate(validateTplFn, tc.validateExpressions)
		if err == nil {
			if tc.expErr != "" {
				t.Errorf("expected to get err %q; got nil insted", tc.expErr)
			}
			continue
		}
		if !strings.Contains(err.Error(), tc.expErr) {
			t.Errorf("expected err to contain %q; got %q instead", tc.expErr, err)
		}
	}
}

func TestHashRule(t *testing.T) {
	testCases := []struct {
		a, b  Rule
		equal bool
	}{
		{
			Rule{Record: "record", Expr: "up == 1"},
			Rule{Record: "record", Expr: "up == 1"},
			true,
		},
		{
			Rule{Alert: "alert", Expr: "up == 1"},
			Rule{Alert: "alert", Expr: "up == 1"},
			true,
		},
		{
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"foo": "bar",
				"baz": "foo",
			}},
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"foo": "bar",
				"baz": "foo",
			}},
			true,
		},
		{
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"foo": "bar",
				"baz": "foo",
			}},
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"baz": "foo",
				"foo": "bar",
			}},
			true,
		},
		{
			Rule{Alert: "record", Expr: "up == 1"},
			Rule{Alert: "record", Expr: "up == 1"},
			true,
		},
		{
			Rule{Alert: "alert", Expr: "up == 1", For: promutils.NewDuration(time.Minute), KeepFiringFor: promutils.NewDuration(time.Minute)},
			Rule{Alert: "alert", Expr: "up == 1"},
			true,
		},
		{
			Rule{Alert: "record", Expr: "up == 1"},
			Rule{Record: "record", Expr: "up == 1"},
			false,
		},
		{
			Rule{Record: "record", Expr: "up == 1"},
			Rule{Record: "record", Expr: "up == 2"},
			false,
		},
		{
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"foo": "bar",
				"baz": "foo",
			}},
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"baz": "foo",
				"foo": "baz",
			}},
			false,
		},
		{
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"foo": "bar",
				"baz": "foo",
			}},
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"baz": "foo",
			}},
			false,
		},
		{
			Rule{Alert: "alert", Expr: "up == 1", Labels: map[string]string{
				"foo": "bar",
				"baz": "foo",
			}},
			Rule{Alert: "alert", Expr: "up == 1"},
			false,
		},
	}
	for i, tc := range testCases {
		aID, bID := HashRule(tc.a), HashRule(tc.b)
		if tc.equal != (aID == bID) {
			t.Fatalf("missmatch for rule %d", i)
		}
	}
}

func TestGroupChecksum(t *testing.T) {
	f := func(t *testing.T, data, newData string) {
		t.Helper()
		var g Group
		if err := yaml.Unmarshal([]byte(data), &g); err != nil {
			t.Fatalf("failed to unmarshal: %s", err)
		}
		if g.Checksum == "" {
			t.Fatalf("expected to get non-empty checksum")
		}

		var ng Group
		if err := yaml.Unmarshal([]byte(newData), &ng); err != nil {
			t.Fatalf("failed to unmarshal: %s", err)
		}
		if g.Checksum == ng.Checksum {
			t.Fatalf("expected to get different checksums")
		}
	}
	t.Run("Ok", func(t *testing.T) {
		f(t, `
name: TestGroup
rules:
  - alert: ExampleAlertAlwaysFiring
    expr: sum by(job) (up == 1)
  - record: handler:requests:rate5m
    expr: sum(rate(prometheus_http_requests_total[5m])) by (handler)
`, `
name: TestGroup
rules:
  - record: handler:requests:rate5m
    expr: sum(rate(prometheus_http_requests_total[5m])) by (handler)
  - alert: ExampleAlertAlwaysFiring
    expr: sum by(job) (up == 1)
`)
	})

	t.Run("`for` change", func(t *testing.T) {
		f(t, `
name: TestGroup
rules:
  - alert: ExampleAlertWithFor
    expr: sum by(job) (up == 1)
    for: 5m
`, `
name: TestGroup
rules:
  - alert: ExampleAlertWithFor
    expr: sum by(job) (up == 1)
`)
	})
	t.Run("`interval` change", func(t *testing.T) {
		f(t, `
name: TestGroup
interval: 2s
rules:
  - alert: ExampleAlertWithFor
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
interval: 4s
rules:
  - alert: ExampleAlertWithFor
    expr: sum by(job) (up == 1)
`)
	})
	t.Run("`concurrency` change", func(t *testing.T) {
		f(t, `
name: TestGroup
concurrency: 2
rules:
  - alert: ExampleAlertWithFor
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
concurrency: 16
rules:
  - alert: ExampleAlertWithFor
    expr: sum by(job) (up == 1)
`)
	})

	t.Run("`params` change", func(t *testing.T) {
		f(t, `
name: TestGroup
params:
    nocache: ["1"]
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
params:
    nocache: ["0"]
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`)
	})

	t.Run("`limit` change", func(t *testing.T) {
		f(t, `
name: TestGroup
limit: 5
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
limit: 10
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`)
	})

	t.Run("`headers` change", func(t *testing.T) {
		f(t, `
name: TestGroup
headers:
  - "TenantID: foo"
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
headers:
  - "TenantID: bar"
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`)
	})

	t.Run("`notifier_headers` change", func(t *testing.T) {
		f(t, `
name: TestGroup
notifier_headers:
  - "TenantID: foo"
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
notifier_headers:
  - "TenantID: bar"
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`)
	})

	t.Run("`debug` change", func(t *testing.T) {
		f(t, `
name: TestGroup
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
    debug: true
`)
	})
	t.Run("`update_entries_limit` change", func(t *testing.T) {
		f(t, `
name: TestGroup
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
`, `
name: TestGroup
rules:
  - alert: foo
    expr: sum by(job) (up == 1)
    update_entries_limit: 33
`)
	})
}

func TestGroupParams(t *testing.T) {
	f := func(t *testing.T, data string, expParams url.Values) {
		t.Helper()
		var g Group
		if err := yaml.Unmarshal([]byte(data), &g); err != nil {
			t.Fatalf("failed to unmarshal: %s", err)
		}
		got, exp := g.Params.Encode(), expParams.Encode()
		if got != exp {
			t.Fatalf("expected to have %q; got %q", exp, got)
		}
	}

	t.Run("no params", func(t *testing.T) {
		f(t, `
name: TestGroup
rules:
  - alert: ExampleAlertAlwaysFiring
    expr: sum by(job) (up == 1)
`, url.Values{})
	})

	t.Run("params", func(t *testing.T) {
		f(t, `
name: TestGroup
params:
  nocache: ["1"]
  denyPartialResponse: ["true"]
rules:
  - alert: ExampleAlertAlwaysFiring
    expr: sum by(job) (up == 1)
`, url.Values{"nocache": {"1"}, "denyPartialResponse": {"true"}})
	})
}