#import "MLNMapView_Private.h"
#import "MLNSource_Private.h"
#import "MLNStyle_Private.h"
#import "NSBundle+MLNAdditions.h"

#include <mbgl/map/map.hpp>
#include <mbgl/style/source.hpp>
#include <mbgl/style/style.hpp>

const MLNExceptionName MLNInvalidStyleSourceException = @"MLNInvalidStyleSourceException";

@interface MLNSource ()

// Even though this class is abstract, MLNStyle uses it to represent some
// special internal source types like mbgl::AnnotationSource.
@property (nonatomic, readonly) mbgl::style::Source *rawSource;

@property (nonatomic, readonly, weak) id<MLNStylable> stylable;

@end

@implementation MLNSource {
  std::unique_ptr<mbgl::style::Source> _pendingSource;
  mapbox::base::WeakPtr<mbgl::style::Source> _weakSource;
}

- (instancetype)initWithIdentifier:(NSString *)identifier {
  if (self = [super init]) {
    _identifier = [identifier copy];
  }
  return self;
}

- (instancetype)initWithRawSource:(mbgl::style::Source *)rawSource
                         stylable:(id<MLNStylable>)stylable {
  NSString *identifier = @(rawSource->getID().c_str());
  if (self = [self initWithIdentifier:identifier]) {
    _weakSource = rawSource->makeWeakPtr();
    rawSource->peer = SourceWrapper{self};
    _stylable = stylable;
  }
  return self;
}

- (mbgl::style::Source *)rawSource {
  return _weakSource.get();
}

- (instancetype)initWithPendingSource:(std::unique_ptr<mbgl::style::Source>)pendingSource {
  if (self = [self initWithRawSource:pendingSource.get() stylable:nil]) {
    _pendingSource = std::move(pendingSource);
  }
  return self;
}

- (void)addToStylable:(id<MLNStylable>)stylable {
  if (_pendingSource == nullptr) {
    [NSException raise:MLNRedundantSourceException
                format:@"This instance %@ was already added to %@. Adding the same source instance "
                        "to the style more than once is invalid.",
                       self, stylable.style];
  }

  _stylable = stylable;
  _stylable.style.rawStyle->addSource(std::move(_pendingSource));
}

- (BOOL)removeFromStylable:(id<MLNStylable>)mapView
                     error:(NSError *__nullable *__nullable)outError {
  MLNAssertStyleSourceIsValid();
  BOOL removed = NO;

  if (self.rawSource == mapView.style.rawStyle->getSource(self.identifier.UTF8String)) {
    auto removedSource = mapView.style.rawStyle->removeSource(self.identifier.UTF8String);

    if (removedSource) {
      removed = YES;
      _pendingSource = std::move(removedSource);
      _stylable = nil;
    } else if (outError) {
      NSString *localizedDescription = [NSString
          stringWithFormat:
              NSLocalizedStringWithDefaultValue(
                  @"REMOVE_SRC_FAIL_IN_USE_FMT", @"Foundation", nil,
                  @"The source “%@” can’t be removed while it is in use.",
                  @"User-friendly error description; first placeholder is the source’s identifier"),
              self.identifier];

      *outError = [NSError errorWithDomain:MLNErrorDomain
                                      code:MLNErrorCodeSourceIsInUseCannotRemove
                                  userInfo:@{NSLocalizedDescriptionKey : localizedDescription}];
    }
  } else if (outError) {
    // TODO: Consider raising an exception here
    NSString *localizedDescription =
        [NSString stringWithFormat:NSLocalizedStringWithDefaultValue(
                                       @"REMOVE_SRC_FAIL_MISMATCH_FMT", @"Foundation", nil,
                                       @"The source can’t be removed because its identifier, “%@”, "
                                       @"belongs to a different source in this style.",
                                       @"User-friendly error description"),
                                   self.identifier];

    *outError = [NSError errorWithDomain:MLNErrorDomain
                                    code:MLNErrorCodeSourceIdentifierMismatch
                                userInfo:@{NSLocalizedDescriptionKey : localizedDescription}];
  }

  return removed;
}

- (NSString *)description {
  return [NSString stringWithFormat:@"<%@: %p; identifier = %@>", NSStringFromClass([self class]),
                                    (void *)self, self.identifier];
}

@end