// NOTICE: GOTO is evil. 
(function(Scratch) {
  'use strict';

  if (!Scratch.extensions.unsandboxed) {
    throw new Error('This Hello World example must run unsandboxed');
  }
  
  let gotoLabels = new Map();
  
  let resetVars = () => gotoLabels = new Map();
  
  Scratch.vm.on("PROJECT_START", resetVars);
  
  Scratch.vm.on("PROJECT_STOP", resetVars);

  class GOTO {
    getInfo() {
      return {
        id: 'helloworldunsandboxed',
        name: 'Unsandboxed Hello World',
        blocks: [
          {
            opcode: 'createGotoLabel',
            blockType: Scratch.BlockType.COMMAND,
            text: "create goto label with name [name] for this script",
            arguments: {
              name: {
                type: Scratch.ArgumentType.STRING,
                defaultValue: "label"
              }
            }
          },
          {
            opcode: "gotoLabel",
            blockType: Scratch.BlockType.COMMAND,
            text: "skip to label with [name] in this script",
            arguments: {
              name: {
                type: Scratch.ArgumentType.STRING,
                defaultValue: "label",
              }
            }
          }
        ]
      };
    }
    createGotoLabel({name}, util) {
      if (!gotoLabels.get(util.thread)) {
        gotoLabels.set(util.thread, {})
      }
      
      
      // set current
      if (!gotoLabels.get(util.thread)[name]) {
        // util.thread.peekStack gives either opcode or the block id.
        gotoLabels.get(util.thread)[name] = util.thread.peekStack();
      } else {
        console.log("imagine creating the same goto label twice, as if goto wasnt already evil enough")
      }
      
    }
    
    gotoLabel({name}, util) {
      // if this block fails it doesnt goto
      let blockId = gotoLabels.get(util.thread)[name];
      
      console.log(util.thread.stack)
      
      if (blockId && util.target.blocks._blocks[blockId].id) {
        //console.log(util.target.blocks._blocks[blockId]);
        //util.thread.pushStack(util.target.blocks._blocks[blockId].id);
        util.thread.stack[util.thread.stack.length - 1] = blockId
      }
      
      console.log(util.thread.stack)
    }
  }
  Scratch.extensions.register(new GOTO());
})(Scratch);