lib/equestreum/chain.rb in equestreum-0.1.1 vs lib/equestreum/chain.rb in equestreum-0.1.2

@@ -1,25 +1,84 @@
 module Equestreum
   class Chain < Array
     private :push, :append, :<<
+    attr_accessor :genesis_data, :difficulty, :path
 
-    def initialize genesis
-      push genesis
+    def initialize
+      @genesis_data = 'genesis block'
+      @difficulty = 3
+      @path = Config.instance.config['chain_path']
+      yield self if block_given?
+
+      grow @genesis_data,
+        prev: '0000000000000000000000000000000000000000000000000000000000000000'
     end
 
-    def grow data
+    def path= path
+      Config.instance.config['chain_path'] = path
+    end
+
+    def self.difficulty= diff
+      c = self.revive
+      c.difficulty = diff
+      c.save
+    end
+
+    def self.difficulty
+      self.revive.difficulty
+    end
+
+    def self.init difficulty: 3
+      diff = Config.instance.config['difficulty'] ? Config.instance.config['difficulty'] : difficulty
+      unless File.exists? Config.instance.config['chain_path']
+        chain = Chain.new do |c|
+          c.difficulty = diff
+        end
+        chain.save
+      end
+    end
+
+    def grow data, prev: nil
       block = Block.new do |b|
         b.data = data
-        b.prev = self.last.hash
-        b.difficulty = self.last.difficulty
+        b.prev = prev ? prev : self.last.hash
+        b.difficulty = @difficulty
       end
 
       block.mine
-
       push block
     end
 
+    def self.grow data
+      chain = self.revive
+      chain.grow data
+      chain.save
+
+      chain
+    end
+
+    def data with_genesis: false
+      data = self.map do |b|
+        {
+          datetime: Time.at(b.time).iso8601,
+          data: b.data
+        }
+      end
+
+      data.shift unless with_genesis
+
+      data
+    end
+
+    def self.aggregate
+      h = Hash.new 0
+      Chain.revive[1..-1].each do |block|
+        h[block.data] += 1
+      end
+      h
+    end
+
     def hash_ok? index
       block = self[index]
 
       block.hash == (Digest::SHA256.hexdigest '%s%s%s%s%s' % [
         block.nonce,
@@ -30,11 +89,13 @@
       ])
     end
 
     def hashes_ok?
       self.length.times do |index|
-        raise EquestreumException.new "Block at #{index} tampered with" unless hash_ok? index
+        unless hash_ok? index
+          raise EquestreumException.new "Block at #{index} tampered with"
+        end
       end
       true
     end
 
     def proof_of_work_ok? index
@@ -65,26 +126,35 @@
 
     def newer_than_last? index
       return true if index == 0
       block = self[index]
       previous = self[index - 1]
-      block.time > previous.time
+      block.time >= previous.time
     end
 
     def blocks_get_newer?
       self.length.times do |index|
         raise EquestreumException.new "Block at #{index} seems older than its predecessor" unless newer_than_last? index
       end
       true
     end
 
+    def verified?
+      hashes_ok? && proofs_of_work_ok? && previous_hashes_ok? && blocks_get_newer?
+    end
+
     def save
+      FileUtils.mkdir_p File.dirname Config.instance.config['chain_path']
       File.open Config.instance.config['chain_path'], 'w' do |f|
         f.write Marshal.dump self
       end
     end
 
     def self.revive
-      Marshal.load File.read Config.instance.config['chain_path']
+      begin
+        Marshal.load File.read Config.instance.config['chain_path']
+      rescue Errno::ENOENT
+        raise EquestreumException.new "no chain found at #{Config.instance.config['chain_path']}"
+      end
     end
   end
 end