package dehub

import (
	"dehub/sigcred"
	"reflect"
	"strings"
	"testing"

	"github.com/davecgh/go-spew/spew"
	"gopkg.in/src-d/go-git.v4/plumbing"
	yaml "gopkg.in/yaml.v2"
)

func TestChangeCommitVerify(t *testing.T) {
	type step struct {
		msg     string
		msgHead string // defaults to msg
		tree    map[string]string
	}
	testCases := []struct {
		descr string
		steps []step
	}{
		{
			descr: "single commit",
			steps: []step{
				{
					msg:  "first commit",
					tree: map[string]string{"a": "0", "b": "1"},
				},
			},
		},
		{
			descr: "multiple commits",
			steps: []step{
				{
					msg:  "first commit",
					tree: map[string]string{"a": "0", "b": "1"},
				},
				{
					msg:  "second commit, changing a",
					tree: map[string]string{"a": "1"},
				},
				{
					msg: "third commit, empty",
				},
				{
					msg:  "fourth commit, adding c, removing b",
					tree: map[string]string{"b": "", "c": "2"},
				},
			},
		},
		{
			descr: "big body commits",
			steps: []step{
				{
					msg: "first commit, single line but with newline\n",
				},
				{
					msg:     "second commit, single line but with two newlines\n\n",
					msgHead: "second commit, single line but with two newlines\n\n",
				},
				{
					msg:     "third commit, multi-line with one newline\nanother line!",
					msgHead: "third commit, multi-line with one newline\n\n",
				},
				{
					msg:     "fourth commit, multi-line with two newlines\n\nanother line!",
					msgHead: "fourth commit, multi-line with two newlines\n\n",
				},
			},
		},
	}

	for _, test := range testCases {
		t.Run(test.descr, func(t *testing.T) {
			h := newHarness(t)
			for _, step := range test.steps {
				h.stage(step.tree)
				account := h.cfg.Accounts[0]

				gitCommit := h.changeCommit(step.msg, account.ID, h.sig)
				if step.msgHead == "" {
					step.msgHead = strings.TrimSpace(step.msg) + "\n\n"
				}

				if !strings.HasPrefix(gitCommit.GitCommit.Message, step.msgHead) {
					t.Fatalf("commit message %q does not start with expected head %q",
						gitCommit.GitCommit.Message, step.msgHead)
				}

				var actualCommit Commit
				if err := actualCommit.UnmarshalText([]byte(gitCommit.GitCommit.Message)); err != nil {
					t.Fatalf("error unmarshaling commit body: %v", err)
				} else if !reflect.DeepEqual(actualCommit, gitCommit.Commit) {
					t.Fatalf("returned change commit:\n%s\ndoes not match actual one:\n%s",
						spew.Sdump(gitCommit.Commit), spew.Sdump(actualCommit))
				}
			}
		})
	}
}

func TestCombineCommitChanges(t *testing.T) {
	h := newHarness(t)

	// commit initial config, so the root user can modify it in the next commit
	h.changeCommit("initial commit", h.cfg.Accounts[0].ID, h.sig)

	// add a toot user and modify the access controls such that both accounts
	// are required for the main branch
	tootSig, tootPubKeyBody := sigcred.SignifierPGPTmp("toot", h.rand)
	h.cfg.Accounts = append(h.cfg.Accounts, Account{
		ID: "toot",
		Signifiers: []sigcred.Signifier{{PGPPublicKey: &sigcred.SignifierPGP{
			Body: string(tootPubKeyBody),
		}}},
	})
	err := yaml.Unmarshal([]byte(`
- action: allow
  filters:
  - type: branch
    pattern: main
  - type: commit_type
    commit_type: change
  - type: signature
    any_account: true
    count: 2

- action: allow
  filters:
  - type: not
    filter:
      type: branch
      pattern: main
  - type: signature
    any_account: true
    count: 1

- action: deny
`), &h.cfg.AccessControls)
	if err != nil {
		t.Fatal(err)
	}

	h.stageCfg()
	tootCommit := h.changeCommit("add toot", h.cfg.Accounts[0].ID, h.sig)

	// make a single change commit in another branch using root. Then add a
	// credential using toot, and combine them onto main.
	otherBranch := plumbing.NewBranchReferenceName("other")
	h.checkout(otherBranch)
	h.stage(map[string]string{"foo": "bar"})
	fooCommit := h.changeCommit("add foo file", h.cfg.Accounts[0].ID, h.sig)

	// now adding a credential commit from toot should work
	credCommitObj, err := h.repo.NewCommitCredential(fooCommit.Interface.GetHash())
	if err != nil {
		t.Fatal(err)
	}
	credCommit := h.tryCommit(true, credCommitObj, h.cfg.Accounts[1].ID, tootSig)

	allCommits, err := h.repo.GetGitCommitRange(
		tootCommit.GitCommit.Hash,
		credCommit.GitCommit.Hash,
	)
	if err != nil {
		t.Fatalf("error getting commits: %v", err)
	}

	combinedCommit, err := h.repo.CombineCommitChanges(allCommits, MainRefName)
	if err != nil {
		t.Fatal(err)
	}

	// that new commit should have both credentials
	creds := combinedCommit.Commit.Common.Credentials
	if len(creds) != 2 {
		t.Fatalf("combined commit has %d credentials, not 2", len(creds))
	} else if creds[0].AccountID != "root" {
		t.Fatalf("combined commit first credential should be from root, is from %q", creds[0].AccountID)
	} else if creds[1].AccountID != "toot" {
		t.Fatalf("combined commit second credential should be from toot, is from %q", creds[1].AccountID)
	}

	// double check that the HEAD commit of main got properly set
	h.checkout(MainRefName)
	mainHead, err := h.repo.GetGitHead()
	if err != nil {
		t.Fatal(err)
	} else if mainHead.GitCommit.Hash != combinedCommit.GitCommit.Hash {
		t.Fatalf("mainHead's should be pointed at %s but is pointed at %s",
			combinedCommit.GitCommit.Hash, mainHead.GitCommit.Hash)
	} else if err = h.repo.VerifyCommits(MainRefName, []GitCommit{combinedCommit}); err != nil {
		t.Fatalf("unable to verify combined commit: %v", err)
	} else if author := combinedCommit.GitCommit.Author.Name; author != "root" {
		t.Fatalf("unexpected author value %q", author)
	}
}