package tasks

import "testing"

func TestPostgresMaxRowsPerStatement(t *testing.T) {
	tests := []struct {
		name   string
		cols   int
		expect int
	}{
		{name: "zero columns", cols: 0, expect: 1},
		{name: "hourly cache columns", cols: 17, expect: 3855},
		{name: "hourly snapshot columns", cols: 20, expect: 3276},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			got := postgresMaxRowsPerStatement(tc.cols)
			if got != tc.expect {
				t.Fatalf("unexpected max rows: cols=%d got=%d want=%d", tc.cols, got, tc.expect)
			}
		})
	}
}

func TestBuildPostgresMultiRowInsertSQL(t *testing.T) {
	got := buildPostgresMultiRowInsertSQL("vm_hourly_stats", []string{"A", "B"}, 2, "")
	want := `INSERT INTO vm_hourly_stats ("A","B") VALUES ($1,$2),($3,$4)`
	if got != want {
		t.Fatalf("unexpected SQL\nwant: %s\ngot:  %s", want, got)
	}

	withSuffix := buildPostgresMultiRowInsertSQL("vm_hourly_stats", []string{"A"}, 1, ` ON CONFLICT ("A") DO NOTHING`)
	wantSuffix := `INSERT INTO vm_hourly_stats ("A") VALUES ($1) ON CONFLICT ("A") DO NOTHING`
	if withSuffix != wantSuffix {
		t.Fatalf("unexpected SQL with suffix\nwant: %s\ngot:  %s", wantSuffix, withSuffix)
	}
}

func TestIsLegacyIsPresentError(t *testing.T) {
	if !isLegacyIsPresentError(assertErr(`null value in column "IsPresent" violates not-null constraint`)) {
		t.Fatal("expected legacy IsPresent error to be detected")
	}
	if isLegacyIsPresentError(assertErr("duplicate key value violates unique constraint")) {
		t.Fatal("expected non-IsPresent errors to be ignored")
	}
}

type testErr string

func (e testErr) Error() string { return string(e) }

func assertErr(msg string) error { return testErr(msg) }