// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package main

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"regexp"
	"strings"
	"testing"

	"go.fuchsia.dev/fuchsia/tools/build"
	"go.fuchsia.dev/fuchsia/tools/integration/testsharder"
	"go.fuchsia.dev/fuchsia/tools/net/sshutil"
	"go.fuchsia.dev/fuchsia/tools/testing/runtests"
	"go.fuchsia.dev/fuchsia/tools/testing/tap"
	"go.fuchsia.dev/fuchsia/tools/testing/testrunner"
)

const (
	testFunc        = "Test"
	copySinksFunc   = "EnsureSinks"
	runSnapshotFunc = "RunSnapshot"
)

type fakeTester struct {
	testErr   error
	runTest   func(testsharder.Test, io.Writer, io.Writer)
	funcCalls []string
	outDirs   map[string]bool
}

func (t *fakeTester) Test(_ context.Context, test testsharder.Test, stdout, stderr io.Writer, outDir string) (runtests.DataSinkReference, error) {
	t.funcCalls = append(t.funcCalls, testFunc)
	if t.outDirs == nil {
		t.outDirs = make(map[string]bool)
	}
	t.outDirs[outDir] = true
	if t.runTest != nil {
		t.runTest(test, stdout, stderr)
	}
	return nil, t.testErr
}

func (t *fakeTester) Close() error {
	return nil
}

func (t *fakeTester) EnsureSinks(_ context.Context, _ []runtests.DataSinkReference) error {
	t.funcCalls = append(t.funcCalls, copySinksFunc)
	return nil
}

func (t *fakeTester) RunSnapshot(_ context.Context, _ string) error {
	t.funcCalls = append(t.funcCalls, runSnapshotFunc)
	return nil
}

func assertEqual(t1, t2 *testrunner.TestResult) bool {
	return (t1.Name == t2.Name &&
		t1.Result == t2.Result &&
		t1.RunIndex == t2.RunIndex &&
		string(t1.Stdio) == string(t2.Stdio))
}

func TestValidateTest(t *testing.T) {
	cases := []struct {
		name      string
		test      testsharder.Test
		expectErr bool
	}{
		{
			name: "missing name",
			test: testsharder.Test{
				Test: build.Test{
					OS:   "linux",
					Path: "/foo/bar",
				},
				Runs: 1,
			},
			expectErr: true,
		}, {
			name: "missing OS",
			test: testsharder.Test{
				Test: build.Test{
					Name: "test1",
					Path: "/foo/bar",
				},
				Runs: 1,
			},
			expectErr: true,
		}, {
			name: "spurious package URL",
			test: testsharder.Test{
				Test: build.Test{
					Name:       "test1",
					OS:         "linux",
					PackageURL: "fuchsia-pkg://test1",
				},
				Runs: 1,
			},
			expectErr: true,
		},
		{
			name: "missing required path",
			test: testsharder.Test{
				Test: build.Test{
					Name: "test1",
					OS:   "linux",
				},
				Runs: 1,
			},
			expectErr: true,
		},
		{
			name: "missing required package_url or path",
			test: testsharder.Test{
				Test: build.Test{
					Name: "test1",
					OS:   "fuchsia",
				},
				Runs: 1,
			},
			expectErr: true,
		}, {
			name: "missing runs",
			test: testsharder.Test{
				Test: build.Test{
					Name: "test1",
					OS:   "linux",
					Path: "/foo/bar",
				},
			},
			expectErr: true,
		}, {
			name: "missing run algorithm",
			test: testsharder.Test{
				Test: build.Test{
					Name: "test1",
					OS:   "linux",
					Path: "/foo/bar",
				},
				Runs: 2,
			},
			expectErr: true,
		}, {
			name: "valid test with path",
			test: testsharder.Test{
				Test: build.Test{
					Name: "test1",
					OS:   "linux",
					Path: "/foo/bar",
				},
				Runs: 1,
			},
			expectErr: false,
		}, {
			name: "valid test with packageurl",
			test: testsharder.Test{
				Test: build.Test{
					Name:       "test1",
					OS:         "fuchsia",
					PackageURL: "fuchsia-pkg://test1",
				},
				Runs:         5,
				RunAlgorithm: testsharder.KeepGoing,
			},
			expectErr: false,
		},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			err := validateTest(c.test)
			if c.expectErr != (err != nil) {
				t.Errorf("got error: %v, expectErr: %v", err, c.expectErr)
			}
		})
	}
}

func TestRunTest(t *testing.T) {
	cases := []struct {
		name           string
		test           build.Test
		runs           int
		runAlgorithm   testsharder.RunAlgorithm
		testErr        error
		runTestFunc    func(testsharder.Test, io.Writer, io.Writer)
		expectedErr    error
		expectedResult []*testrunner.TestResult
	}{
		{
			name: "host test pass",
			test: build.Test{
				Name: "bar",
				Path: "/foo/bar",
				OS:   "linux",
			},
			testErr: nil,
			expectedResult: []*testrunner.TestResult{{
				Name:   "bar",
				Result: runtests.TestSuccess,
			}},
		},
		{
			name: "fuchsia test pass",
			test: build.Test{
				Name:       "bar",
				Path:       "/foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			testErr: nil,
			expectedResult: []*testrunner.TestResult{{
				Name:   "bar",
				Result: runtests.TestSuccess,
			}},
		},
		{
			name: "fuchsia test fail",
			test: build.Test{
				Name:       "bar",
				Path:       "/foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			testErr: fmt.Errorf("test failed"),
			expectedResult: []*testrunner.TestResult{{
				Name:   "bar",
				Result: runtests.TestFailure,
			}},
		},
		{
			name: "fuchsia test ssh connection fail",
			test: build.Test{
				Name:       "bar",
				Path:       "/foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			testErr:        sshutil.ConnectionError{},
			expectedErr:    sshutil.ConnectionError{},
			expectedResult: nil,
		},
		{
			name: "multiplier test gets unique index",
			test: build.Test{
				Name:       "bar (2)",
				Path:       "/foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			runs:         2,
			runAlgorithm: testsharder.KeepGoing,
			testErr:      nil,
			expectedResult: []*testrunner.TestResult{{
				Name:   "bar (2)",
				Result: runtests.TestSuccess,
			}, {
				Name:     "bar (2)",
				Result:   runtests.TestSuccess,
				RunIndex: 1,
			}},
		}, {
			name: "combines stdio and stdout in chronological order",
			test: build.Test{
				Name:       "fuchsia-pkg://foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			expectedResult: []*testrunner.TestResult{{
				Name:   "fuchsia-pkg://foo/bar",
				Result: runtests.TestSuccess,
				Stdio:  []byte("stdout stderr stdout"),
			}},
			runTestFunc: func(t testsharder.Test, stdout, stderr io.Writer) {
				stdout.Write([]byte("stdout "))
				stderr.Write([]byte("stderr "))
				stdout.Write([]byte("stdout"))
			},
		}, {
			name: "retries test",
			test: build.Test{
				Name:       "fuchsia-pkg://foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			runs:         6,
			runAlgorithm: testsharder.StopOnSuccess,
			testErr:      fmt.Errorf("test failed"),
			expectedResult: []*testrunner.TestResult{
				{
					Name:   "fuchsia-pkg://foo/bar",
					Result: runtests.TestFailure,
					Stdio:  []byte("stdio"),
				},
				{
					Name:     "fuchsia-pkg://foo/bar",
					Result:   runtests.TestFailure,
					RunIndex: 1,
					Stdio:    []byte("stdio"),
				},
				{
					Name:     "fuchsia-pkg://foo/bar",
					Result:   runtests.TestFailure,
					RunIndex: 2,
					Stdio:    []byte("stdio"),
				},
				{
					Name:     "fuchsia-pkg://foo/bar",
					Result:   runtests.TestFailure,
					RunIndex: 3,
					Stdio:    []byte("stdio"),
				},
				{
					Name:     "fuchsia-pkg://foo/bar",
					Result:   runtests.TestFailure,
					RunIndex: 4,
					Stdio:    []byte("stdio"),
				},
				{
					Name:     "fuchsia-pkg://foo/bar",
					Result:   runtests.TestFailure,
					RunIndex: 5,
					Stdio:    []byte("stdio"),
				},
			},
			runTestFunc: func(t testsharder.Test, stdout, stderr io.Writer) {
				stdout.Write([]byte("stdio"))
			},
		},
		{
			name: "returns on first success even if max attempts > 1",
			test: build.Test{
				Name:       "fuchsia-pkg://foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			runs:         5,
			runAlgorithm: testsharder.StopOnSuccess,
			expectedResult: []*testrunner.TestResult{{
				Name:   "fuchsia-pkg://foo/bar",
				Result: runtests.TestSuccess,
			}},
		},
		{
			name: "returns on first failure even if max attempts > 1",
			test: build.Test{
				Name:       "fuchsia-pkg://foo/bar",
				OS:         "fuchsia",
				PackageURL: "fuchsia-pkg://foo/bar",
			},
			runs:         5,
			runAlgorithm: testsharder.StopOnFailure,
			testErr:      fmt.Errorf("test failed"),
			expectedResult: []*testrunner.TestResult{{
				Name:   "fuchsia-pkg://foo/bar",
				Result: runtests.TestFailure,
			}},
		},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			tester := &fakeTester{
				testErr: c.testErr,
				runTest: c.runTestFunc,
			}
			var buf bytes.Buffer
			producer := tap.NewProducer(&buf)
			o, err := createTestOutputs(producer, "")
			if err != nil {
				t.Fatalf("failed to create a test outputs object: %v", err)
			}
			defer o.Close()
			if c.runs == 0 {
				c.runs = 1
			}
			results, err := runAndOutputTest(context.Background(), testsharder.Test{Test: c.test, Runs: c.runs, RunAlgorithm: c.runAlgorithm}, tester, o, &buf, &buf, "out-dir")

			if err != c.expectedErr {
				t.Errorf("got error: %v, expected: %v", err, c.expectedErr)
			}
			if err == nil {
				for j, result := range results {
					if !assertEqual(result, c.expectedResult[j]) {
						t.Errorf("got result: %v, expected: %v", result, c.expectedResult[j])
					}
				}
			}
			if c.runs > 1 {
				funcCalls := strings.Join(tester.funcCalls, ",")
				testCount := strings.Count(funcCalls, testFunc)
				expectedTries := 1
				if (c.runAlgorithm == testsharder.StopOnSuccess && c.testErr != nil) || c.runAlgorithm == testsharder.KeepGoing {
					expectedTries = c.runs
				}
				if testCount != expectedTries {
					t.Errorf("ran test %d times, expected: %d", testCount, expectedTries)
				}
				// Each try should have a unique outDir
				if len(tester.outDirs) != expectedTries {
					t.Errorf("got %d unique outDirs, expected %d", len(tester.outDirs), expectedTries)
				}
			}
			expectedOutput := ""
			for i, result := range c.expectedResult {
				statusString := "ok"
				if result.Result != runtests.TestSuccess {
					statusString = "not ok"
				}
				expectedOutput += fmt.Sprintf("%s%s %d %s (.*)\n", result.Stdio, statusString, i+1, result.Name)
			}
			actualOutput := buf.String()
			expectedOutputRegex := regexp.MustCompile(strings.ReplaceAll(strings.ReplaceAll(expectedOutput, "(", "\\("), ")", "\\)"))
			submatches := expectedOutputRegex.FindStringSubmatch(actualOutput)
			if len(submatches) != 1 {
				t.Errorf("unexpected output:\nexpected: %v\nactual: %v\n", expectedOutput, actualOutput)
			}

		})
	}
}