From 9b092aceb2bdebec5a1ad14d6166900b783da521 Mon Sep 17 00:00:00 2001
From: Matt Diephouse <matt@diephouse.com>
Date: Wed, 24 Feb 2016 11:14:10 -0500
Subject: [PATCH] Add APIs to calculate and cleanup repository states

---
 ObjectiveGit/GTRepository.h          | 31 +++++++++++++++++++++++
 ObjectiveGit/GTRepository.m          | 21 +++++++++++++++
 ObjectiveGitTests/GTRepositorySpec.m | 38 ++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+)

diff --git a/ObjectiveGit/GTRepository.h b/ObjectiveGit/GTRepository.h
index 566953624..45f3caead 100644
--- a/ObjectiveGit/GTRepository.h
+++ b/ObjectiveGit/GTRepository.h
@@ -150,6 +150,20 @@ extern NSString * const GTRepositoryInitOptionsInitialHEAD;
 /// initialization.
 extern NSString * const GTRepositoryInitOptionsOriginURLString;
 
+/// The possible states for the repository to be in, based on the current ongoing operation.
+typedef NS_ENUM(NSInteger, GTRepositoryStateType) {
+	GTRepositoryStateNone = GIT_REPOSITORY_STATE_NONE,
+	GTRepositoryStateMerge = GIT_REPOSITORY_STATE_MERGE,
+	GTRepositoryStateRevert = GIT_REPOSITORY_STATE_REVERT,
+	GTRepositoryStateCherryPick = GIT_REPOSITORY_STATE_CHERRYPICK,
+	GTRepositoryStateBisect = GIT_REPOSITORY_STATE_BISECT,
+	GTRepositoryStateRebase = GIT_REPOSITORY_STATE_REBASE,
+	GTRepositoryStateRebaseInteractive = GIT_REPOSITORY_STATE_REBASE_INTERACTIVE,
+	GTRepositoryStateRebaseMerge = GIT_REPOSITORY_STATE_REBASE_MERGE,
+	GTRepositoryStateApplyMailbox = GIT_REPOSITORY_STATE_APPLY_MAILBOX,
+	GTRepositoryStateApplyMailboxOrRebase = GIT_REPOSITORY_STATE_APPLY_MAILBOX_OR_REBASE,
+};
+
 @interface GTRepository : NSObject
 
 /// The file URL for the repository's working directory.
@@ -573,6 +587,23 @@ extern NSString * const GTRepositoryInitOptionsOriginURLString;
 /// Returns the enumerator or nil if an error occurred.
 - (nullable GTEnumerator *)enumeratorForUniqueCommitsFromOID:(GTOID *)fromOID relativeToOID:(GTOID *)relativeOID error:(NSError **)error;
 
+/// Determines the status of a git repository--i.e., whether an operation
+/// (merge, cherry-pick, etc) is in progress.
+///
+/// state - A pointer to set the retrieved state. Must not be NULL.
+/// error - The error if one occurred.
+///
+/// Returns YES if operation was successful, NO otherwise
+- (BOOL)calculateState:(GTRepositoryStateType *)state withError:(NSError **)error;
+
+/// Remove all the metadata associated with an ongoing command like merge,
+/// revert, cherry-pick, etc.  For example: MERGE_HEAD, MERGE_MSG, etc.
+///
+/// error - The error if one occurred.
+///
+/// Returns YES if operation was successful, NO otherwise
+- (BOOL)cleanupStateWithError:(NSError **)error;
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/ObjectiveGit/GTRepository.m b/ObjectiveGit/GTRepository.m
index 332c565f4..c2483ab57 100644
--- a/ObjectiveGit/GTRepository.m
+++ b/ObjectiveGit/GTRepository.m
@@ -898,4 +898,25 @@ - (nullable GTEnumerator *)enumeratorForUniqueCommitsFromOID:(GTOID *)fromOID re
 	return enumerator;
 }
 
+- (BOOL)calculateState:(GTRepositoryStateType *)state withError:(NSError **)error {
+	NSParameterAssert(state != NULL);
+	
+	int result = git_repository_state(self.git_repository);
+	if (result < 0) {
+		if (error != NULL) *error = [NSError git_errorFor:result description:@"Failed to calculate repository state"];
+		return NO;
+	}
+	
+	*state = result;
+	return YES;
+}
+
+- (BOOL)cleanupStateWithError:(NSError * _Nullable __autoreleasing *)error {
+	int errorCode = git_repository_state_cleanup(self.git_repository);
+	if (errorCode != GIT_OK) {
+		if (error != NULL) *error = [NSError git_errorFor:errorCode description:@"Failed to clean up repository state"];
+	}
+	return YES;
+}
+
 @end
diff --git a/ObjectiveGitTests/GTRepositorySpec.m b/ObjectiveGitTests/GTRepositorySpec.m
index 4837cea71..8c7740dcc 100644
--- a/ObjectiveGitTests/GTRepositorySpec.m
+++ b/ObjectiveGitTests/GTRepositorySpec.m
@@ -700,6 +700,44 @@
 	});
 });
 
+describe(@"-calculateState:withError:", ^{
+	it(@"should find if the repository is mid-merge", ^{
+		GTRepository *repository = [self conflictedFixtureRepository];
+		GTRepositoryStateType state;
+		BOOL result;
+		result = [repository calculateState:&state withError:NULL];
+		expect(@(result)).to(beTruthy());
+		expect(@(state)).to(equal(@(GTRepositoryStateMerge)));
+	});
+	
+	it(@"should return none otherwise", ^{
+		GTRepository *repository = [self testAppFixtureRepository];
+		GTRepositoryStateType state;
+		BOOL result;
+		result = [repository calculateState:&state withError:NULL];
+		expect(@(result)).to(beTruthy());
+		expect(@(state)).to(equal(@(GTRepositoryStateNone)));
+	});
+});
+
+describe(@"-cleanupStateWithError:", ^{
+	it(@"should return a repository to a pre-merge state", ^{
+		GTRepository *repository = [self conflictedFixtureRepository];
+		
+		GTRepositoryStateType state;
+		BOOL result;
+		result = [repository calculateState:&state withError:NULL];
+		expect(@(result)).to(beTruthy());
+		expect(@(state)).to(equal(@(GTRepositoryStateMerge)));
+		
+		expect(@([repository cleanupStateWithError:NULL])).to(beTruthy());
+		
+		result = [repository calculateState:&state withError:NULL];
+		expect(@(result)).to(beTruthy());
+		expect(@(state)).to(equal(@(GTRepositoryStateNone)));
+	});
+});
+
 afterEach(^{
 	[self tearDown];
 });