package dehub

import (
	"reflect"
	"strings"
	"testing"

	"github.com/davecgh/go-spew/spew"
)

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))
				}
			}
		})
	}
}