RSpec.describe Pry::Config do
  describe ".from_hash" do
    it "returns an object without a default" do
      local = described_class.from_hash({})
      expect(local.default).to eq(nil)
    end

    it "returns an object with a default" do
      default = described_class.new(nil)
      local = described_class.from_hash({}, default)
      expect(local.default).to eq(local)
    end

    it "recursively walks a Hash" do
      h = { 'foo1' => { 'foo2' => { 'foo3' => 'foobar' } } }
      default = described_class.from_hash(h)
      expect(default.foo1).to be_instance_of(described_class)
      expect(default.foo1.foo2).to be_instance_of(described_class)
    end

    it "recursively walks an Array" do
      c = described_class.from_hash(ary: [{ number: 2 }, Object])
      expect(c.ary[0].number).to eq(2)
      expect(c.ary[1]).to eq(Object)
    end
  end

  describe "bug #1552" do
    specify(
      "a local key has precendence over its default when the stored value is false"
    ) do
      local = described_class.from_hash({}, described_class.from_hash('color' => true))
      local.color = false
      expect(local.color).to eq(false)
    end
  end

  describe "bug #1277" do
    specify "a local key has precendence over an inherited method of the same name" do
      local = described_class.from_hash(output: 'foobar')
      local.extend(
        Module.new do
          def output
            'broken'
          end
        end
      )
      expect(local.output).to eq('foobar')
    end
  end

  describe "reserved keys" do
    it "raises ReservedKeyError on assignment of a reserved key" do
      local = described_class.new
      local.instance_variable_get(:@reserved_keys).each do |key|
        expect { local[key] = 1 }.to raise_error(described_class::ReservedKeyError)
      end
    end
  end

  describe "traversal to parent" do
    it "traverses back to the parent when a local key is not found" do
      local = described_class.new described_class.from_hash(foo: 1)
      expect(local.foo).to eq(1)
    end

    it "stores a local key and prevents traversal to the parent" do
      local = described_class.new described_class.from_hash(foo: 1)
      local.foo = 2
      expect(local.foo).to eq(2)
    end

    it "traverses through a chain of parents" do
      root = described_class.from_hash(foo: 21)
      local1 = described_class.new(root)
      local2 = described_class.new(local1)
      local3 = described_class.new(local2)
      expect(local3.foo).to eq(21)
    end

    it "stores a local copy of the parents hooks upon accessing them" do
      parent = described_class.from_hash(hooks: "parent_hooks")
      local  = described_class.new parent
      local.hooks.gsub! 'parent', 'local'
      expect(local.hooks).to eq 'local_hooks'
      expect(parent.hooks).to eq('parent_hooks')
    end
  end

  describe "#respond_to_missing?" do
    before do
      @config = described_class.new(nil)
    end

    it "returns a Method object for a dynamic key" do
      @config["key"] = 1
      method_obj = @config.method(:key)
      expect(method_obj.name).to eq :key
      expect(method_obj.call).to eq(1)
    end

    it "returns a Method object for a setter on a parent" do
      config = described_class.from_hash({}, described_class.from_hash(foo: 1))
      expect(config.method(:foo=)).to be_an_instance_of(Method)
    end
  end

  describe "#respond_to?" do
    before do
      @config = described_class.new(nil)
    end

    it "returns true for a local key" do
      @config.zzfoo = 1
      expect(@config.respond_to?(:zzfoo)).to eq(true)
    end

    it "returns false for an unknown key" do
      expect(@config.respond_to?(:blahblah)).to eq(false)
    end
  end

  describe "#default" do
    it "returns nil" do
      local = described_class.new(nil)
      expect(local.default).to eq(nil)
    end

    it "returns the default" do
      default = described_class.new(nil)
      local = described_class.new(default)
      expect(local.default).to eq(default)
    end
  end

  describe "#keys" do
    it "returns an array of local keys" do
      root = described_class.from_hash({ zoo: "boo" }, nil)
      local = described_class.from_hash({ foo: "bar" }, root)
      expect(local.keys).to eq(["foo"])
    end
  end

  describe "#==" do
    it "compares equality through the underlying lookup table" do
      local1 = described_class.new(nil)
      local2 = described_class.new(nil)
      local1.foo = "hi"
      local2.foo = "hi"
      expect(local1).to eq(local2)
    end

    it "compares equality against an object who does not implement #to_hash" do
      local1 = described_class.new(nil)
      expect(local1).not_to eq(Object.new)
    end

    it "returns false when compared against nil" do
      # rubocop:disable Style/NilComparison
      expect(described_class.new(nil) == nil).to eq(false)
      # rubocop:enable Style/NilComparison
    end
  end

  describe '#forget' do
    it 'restores a key to its default value' do
      last_default = described_class.from_hash(a: 'c')
      middle_default = described_class.from_hash({ a: 'b' }, last_default)
      c = described_class.from_hash({ a: 'a' }, middle_default)
      c.forget(:a)
      expect(c.a).to eq('c')
    end
  end

  describe "#to_hash" do
    it "provides a copy of local key & value pairs as a Hash" do
      local = described_class.new described_class.from_hash(bar: true)
      local.foo = "21"
      expect(local.to_hash).to eq("foo" => "21")
    end

    it "returns a duplicate of the lookup table" do
      local = described_class.new(nil)
      local.to_hash["foo"] = 42
      expect(local.foo).not_to eq(42)
    end
  end

  describe "#merge!" do
    before do
      @config = described_class.new(nil)
    end

    it "merges an object who returns a Hash through #to_hash" do
      obj = Class.new do
        def to_hash
          { epoch: 1 }
        end
      end.new
      @config.merge!(obj)
      expect(@config.epoch).to eq(1)
    end

    it "merges an object who returns a Hash through #to_h" do
      obj = Class.new do
        def to_h
          { epoch: 2 }
        end
      end.new
      @config.merge!(obj)
      expect(@config.epoch).to eq(2)
    end

    it "merges a Hash" do
      @config[:epoch] = 420
      expect(@config.epoch).to eq(420)
    end

    it "raises a TypeError for objects who can't become a Hash" do
      expect { @config.merge!(Object.new) }.to raise_error TypeError
    end
  end

  describe "#clear" do
    before do
      @local = described_class.new(nil)
    end

    it "returns true" do
      expect(@local.clear).to eq(true)
    end

    it "clears local assignments" do
      @local.foo = 1
      @local.clear
      expect(@local.to_hash).to eq({})
    end
  end

  describe "#[]=" do
    it "stores keys as strings" do
      local = described_class.from_hash({})
      local[:zoo] = "hello"
      expect(local.to_hash).to eq("zoo" => "hello")
    end
  end

  describe "#[]" do
    it "traverses back to a default" do
      default = described_class.from_hash(k: 1)
      local = described_class.new(default)
      expect(local['k']).to eq(1)
    end

    it "traverses back to a default (2 deep)" do
      default1 = described_class.from_hash(k: 1)
      default2 = described_class.from_hash({}, default1)
      local = described_class.new(default2)
      expect(local['k']).to eq(1)
    end

    it "traverses back to a default that doesn't exist, and returns nil" do
      local = described_class.from_hash({}, nil)
      expect(local['output']).to eq(nil)
    end

    context "when returning a Pry::Config::Lazy object" do
      it "invokes #call on it" do
        c = described_class.from_hash foo: Pry.lazy { 10 }
        expect(c['foo']).to eq(10)
      end

      it "invokes #call upon each access" do
        c = described_class.from_hash foo: Pry.lazy { 'foo' }
        expect(c['foo']).to_not equal(c['foo'])
      end
    end
  end

  describe "#eager_load!" do
    it "eagerly loads keys from the last default into self" do
      last_default = described_class.from_hash(foo: 1, bar: 2, baz: 3)
      c = described_class.from_hash({}, last_default)
      expect(c.keys.size).to eq(0)
      c.eager_load!
      expect(c.keys.size).to eq(3)
    end
  end
end