# Copyright, 2017, by Samuel G. D. Williams. <http://www.codeotaku.com>
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RSpec.describe Build::Dependency do
	describe "valid dependency resolution" do
		let(:a) do
			Package.new.tap do |package|
				package.provides 'apple' do
					fruit ['apple']
				end
			end
		end
		
		let(:b) do
			Package.new.tap do |package|
				package.provides 'orange' do
					fruit ['orange']
				end
			end
		end
		
		let(:c) do
			Package.new.tap do |package|
				package.provides 'fruit-juice' do
					juice ['ice', 'cold']
				end
				
				package.depends 'apple'
				package.depends 'orange'
			end
		end
		
		it "should resolve direct dependency chain" do
			chain = Build::Dependency::Chain.expand(['fruit-juice'], [a, b, c])
			expect(chain.ordered.collect(&:first)).to be == [a, b, c]
			expect(chain.unresolved).to be == []
		end
		
		let(:d) do
			Package.new.tap do |package|
				package.provides 'pie'
				package.depends 'apple'
			end
		end
		
		it "shouldn't include unrelated units" do
			chain = Build::Dependency::Chain.expand(['pie'], [a, b, c, d])
			
			expect(chain.unresolved).to be == []
			expect(chain.ordered.collect(&:first)).to be == [a, d]
		end
	end
	
	describe "incomplete dependency resolution" do
		it "should report conflicts" do
			apple = Package.new('apple')
			apple.provides 'apple'
			apple.provides 'fruit'
		
			bananna = Package.new('bananna')
			bananna.provides 'fruit'
		
			salad = Package.new('salad')
			salad.depends 'fruit'
			salad.provides 'salad'
		
			chain = Build::Dependency::Chain.new(['salad'], [apple, bananna, salad])
			expect(chain.unresolved.first).to be == [Build::Dependency::Depends.new("fruit"), salad]
			expect(chain.conflicts).to be == {Build::Dependency::Depends.new("fruit") => [apple, bananna]}
		
			chain = Build::Dependency::Chain.new(['salad'], [apple, bananna, salad], ['apple'])
			expect(chain.unresolved).to be == []
			expect(chain.conflicts).to be == {}
		end
	end
	
	describe "multiple provisions" do
		let(:fruit) do
			Package.new('fruit').tap do |package|
				package.provides 'apple' do
				end
				
				package.provides 'orange' do
				end
			end
		end
		
		let(:salad) do
			Package.new('salad').tap do |package|
				package.depends 'apple'
				package.depends 'orange'
				package.provides 'salad'
			end
		end
		
		let(:lunch) do
			Package.new('lunch').tap do |package|
				package.depends 'apple'
				package.depends 'salad'
				package.provides 'lunch'
			end
		end
		
		let(:chain) {Build::Dependency::Chain.new(['lunch'], [fruit, salad, lunch])}
		
		it "should include both provisions" do
			expect(chain.provisions.count).to be == 4
			expect(chain.provisions.collect(&:name)).to be == ['apple', 'orange', 'salad', 'lunch']
		end
		
		it "should include both provisions in partial chain" do
			partial_chain = chain.partial(lunch)
			expect(partial_chain.provisions.count).to be == 3
			expect(partial_chain.provisions.collect(&:name)).to be == ['apple', 'orange', 'salad']
		end
	end
	
	it "should resolve aliases" do
		apple = Package.new('apple')
		apple.provides 'apple'
		apple.provides :fruit => 'apple'
	
		bananna = Package.new('bananna')
		bananna.provides 'bananna'
		bananna.provides :fruit => 'bananna'
	
		salad = Package.new('salad')
		salad.depends :fruit
		salad.provides 'salad'
	
		chain = Build::Dependency::Chain.expand(['salad'], [apple, bananna, salad], ['apple'])
		expect(chain.unresolved).to be == []
		expect(chain.conflicts).to be == {}
		
		expect(chain.ordered.size).to be == 2
		expect(chain.ordered[0]).to be == Build::Dependency::Resolution.new(apple, Build::Dependency::Depends.new("apple"))
		expect(chain.ordered[1]).to be == Build::Dependency::Resolution.new(salad, Build::Dependency::Depends.new("salad"))
	end
	
	it "should select dependencies with high priority" do
		bad_apple = Package.new('bad_apple')
		bad_apple.provides 'apple'
		bad_apple.priority = 20
		
		good_apple = Package.new('good_apple')
		good_apple.provides 'apple'
		good_apple.priority = 40
		
		chain = Build::Dependency::Chain.expand(['apple'], [bad_apple, good_apple])
		
		expect(chain.unresolved).to be == []
		expect(chain.conflicts).to be == {}
		
		# Should select higher priority package by default:
		expect(chain.ordered).to be == [Build::Dependency::Resolution.new(good_apple, Build::Dependency::Depends.new('apple'))]
	end
	
	it "should expose direct dependencies" do
		system = Package.new('linux')
		system.provides 'linux'
		system.provides 'clang'
		system.provides system: 'linux'
		system.provides compiler: 'clang'
		
		library = Package.new('library')
		library.provides 'library'
		library.depends :system
		library.depends :compiler
		
		application = Package.new('application')
		application.provides 'application'
		application.depends :compiler
		application.depends 'library'
		
		chain = Build::Dependency::Chain.expand(['application'], [system, library, application])
		
		expect(chain.unresolved).to be == []
		expect(chain.conflicts).to be == {}
		expect(chain.ordered).to be == [
			Build::Dependency::Resolution.new(system, Build::Dependency::Depends.new('clang')),
			Build::Dependency::Resolution.new(library, Build::Dependency::Depends.new('library')),
			Build::Dependency::Resolution.new(application, Build::Dependency::Depends.new('application')),
		]
	end
end