// Copyright 2019 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 checkout

import (
	"net/url"
	"testing"

	buildbucketpb "go.chromium.org/luci/buildbucket/proto"
)

func TestNewCheckoutStrategy(t *testing.T) {
	tests := []struct {
		// A name for this test case.
		name string

		// The integration repo URL.
		specRepoURL url.URL

		// The Buildbucket build input.
		input *buildbucketpb.Build_Input

		// The spec ref.
		specRef string

		// The name of the expected strategy.
		expectedStrategy strategy

		// Whether to expect an error
		expectErr bool
	}{
		{
			name: "should checkout from specRef if the gerrit change is for a different project",
			specRepoURL: url.URL{
				Scheme: "https",
				Host:   "fuchsia.googlesource.com",
				Path:   "/repo",
			},
			input: &buildbucketpb.Build_Input{
				GerritChanges: []*buildbucketpb.GerritChange{{
					Host:    "fuchsia-review.googlesource.com",
					Project: "different",
				}},
			},
			specRef: "deadbeef",
			expectedStrategy: &checkoutCommit{
				commit: &buildbucketpb.GitilesCommit{
					Host:    "fuchsia.googlesource.com",
					Project: "repo",
					Id:      "deadbeef",
				},
			},
		},
		{
			name: "should rebase on a parent change if the gerrit change is for the same project",
			specRepoURL: url.URL{
				Scheme: "https",
				Host:   "fuchsia.googlesource.com",
				Path:   "/repo",
			},
			input: &buildbucketpb.Build_Input{
				GitilesCommit: &buildbucketpb.GitilesCommit{
					Host:    "fuchsia.googlesource.com",
					Project: "repo",
					Id:      "deadbeef",
				},
				GerritChanges: []*buildbucketpb.GerritChange{{
					Host:    "fuchsia-review.googlesource.com",
					Project: "repo",
				}},
			},
			expectedStrategy: &checkoutChange{
				parent: &buildbucketpb.GitilesCommit{
					Host:    "fuchsia.googlesource.com",
					Project: "repo",
					Id:      "deadbeef",
				},
				change: &buildbucketpb.GerritChange{
					Host:    "fuchsia-review.googlesource.com",
					Project: "repo",
				},
			},
		},
		{
			name: "should checkout gerrit change if no gitiles commit",
			specRepoURL: url.URL{
				Scheme: "https",
				Host:   "fuchsia.googlesource.com",
				Path:   "/repo",
			},
			input: &buildbucketpb.Build_Input{
				GerritChanges: []*buildbucketpb.GerritChange{{
					Host:    "fuchsia-review.googlesource.com",
					Project: "repo",
				}},
			},
			expectedStrategy: &checkoutChange{
				change: &buildbucketpb.GerritChange{
					Host:    "fuchsia-review.googlesource.com",
					Project: "repo",
				},
			},
		},
		{
			name: "should checkout from specRef if the gitiles commit is for a different project",
			specRepoURL: url.URL{
				Scheme: "https",
				Host:   "fuchsia.googlesource.com",
				Path:   "/repo",
			},
			input: &buildbucketpb.Build_Input{
				GitilesCommit: &buildbucketpb.GitilesCommit{
					Host:    "fuchsia.googlesource.com",
					Project: "different",
				},
			},
			specRef: "deadbeef",
			expectedStrategy: &checkoutCommit{
				commit: &buildbucketpb.GitilesCommit{
					Host:    "fuchsia.googlesource.com",
					Project: "repo",
					Id:      "deadbeef",
				},
			},
		},
		{
			name: "should checkout from the gitiles commit if it is for the same project",
			specRepoURL: url.URL{
				Scheme: "https",
				Host:   "fuchsia.googlesource.com",
				Path:   "/repo",
			},
			input: &buildbucketpb.Build_Input{
				GitilesCommit: &buildbucketpb.GitilesCommit{
					Host:    "fuchsia.googlesource.com",
					Project: "repo",
					Id:      "deadbeef",
				},
			},
			expectedStrategy: &checkoutCommit{
				commit: &buildbucketpb.GitilesCommit{
					Host:    "fuchsia.googlesource.com",
					Project: "repo",
					Id:      "deadbeef",
				},
			},
		},

		// Cases where errors are expected.

		{
			name: "should fail if the build input has no gitiles commit or gerrit change",
			specRepoURL: url.URL{
				Scheme: "https",
				Host:   "fuchsia.googlesource.com",
				Path:   "/repo",
			},
			input:     &buildbucketpb.Build_Input{},
			expectErr: true,
		},
		{
			name: "should fail if the repo URL has no scheme",
			specRepoURL: url.URL{
				Host: "fuchsia.googlesource.com",
				Path: "/repo",
			},
			input:     &buildbucketpb.Build_Input{},
			expectErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.specRef == "" {
				tt.specRef = "HEAD"
			}
			strategy, err := newStrategy(tt.input, tt.specRepoURL, tt.specRef)
			switch {
			case err != nil && !tt.expectErr:
				t.Errorf("unexpected error: %v", err)
				return
			case err == nil && tt.expectErr:
				t.Errorf("wanted an error but got %v", strategy)
				return
			case err != nil && tt.expectErr:
				return
			}

			expected := tt.expectedStrategy
			actual := strategy
			if !expected.Equal(actual) {
				t.Errorf("wanted\n%+v\ngot\n%+v\n", expected, actual)
			}
		})
	}
}

func TestGitilesChangeRef(t *testing.T) {
	test := []struct {
		name     string
		change   *buildbucketpb.GerritChange
		expected string
	}{
		{
			name: "change no. < 10",
			change: &buildbucketpb.GerritChange{
				Change:   9,
				Patchset: 6,
			},
			expected: "refs/changes/09/9/6",
		},
		{
			name: "change no. >= 10",
			change: &buildbucketpb.GerritChange{
				Change:   56,
				Patchset: 6,
			},
			expected: "refs/changes/56/56/6",
		},
		{
			name: "change no. >= 100",
			change: &buildbucketpb.GerritChange{
				Change:   754,
				Patchset: 6,
			},
			expected: "refs/changes/54/754/6",
		},
		{
			name: "change no. >= 1000",
			change: &buildbucketpb.GerritChange{
				Change:   97643,
				Patchset: 6,
			},
			expected: "refs/changes/43/97643/6",
		},
	}

	for _, tt := range test {
		t.Run(tt.name, func(t *testing.T) {
			actual := GitilesChangeRef(tt.change)
			if tt.expected != actual {
				t.Errorf("wanted:%v got %v", tt.expected, actual)
			}
		})
	}
}