What is the complete history of the forerunner from the video game Halo

nobody really knows the history of the forerunners but ill try my best. They were a race that existed thousands and thousands of years ago, they lived in the galaxy that we know today among many other species. over hundreds of years there technologies progressed and along with it there empire eventually they had a massive empire that stretched the galaxy with some amazing technologies. Somepoint in there time they ran into the parasite known as the flood, they were unable to contain them and they spread throughout the galaxy, they continued to fight with them for 300 hundred years whilst studying them further to try and find a weakness, they then found the brain of the flood known as the gravemind which they realised if destroyed could help destroy the flood but as soon as it was destroyed a new one would start to grow. They developed a plan using a highly advanced A.I. called mendicat bias to try and destroy the grave mind at all. Whille this was happening however they realised it may not work and so started on a backup plan, the halos. To create the halos they firstly created the ark to create these weapons. Similar to noahs ark one forerunner called the librarian whent around the galaxy in his forunner ship (simmilar to that in halo 2 and 3) and documented all of the species on all the planets and created a number of portals on these planets that lead to the ark and sent the survivors through. As mendicat bias began its plan the grave mind was able to acces it and turn the A.I against the forerunners and sent an attack on the ark. Another A.I was quickly created to combat Bias and slow the flood attack down. The halos were all built and there had been numerous test firings of each and almost all of the species had been indexed the final planet the librarian went to was earth where he was amazed by its beauty and ability to grow plants on it and he created himself a garden there and a final portal. All of these portals were sealed, only to be opened by the key (the ship in halo 2 and 3) and were burried under the ground. He destroyed most of these ships. Meanwhile the forerunners had no other option but to activiate the ring, they tried to get the librarian back but he refused stating that he was in paradise and so they activated the rings destroying all remaining sentiant life and the flood The forerunners however had wanted to study the flodd further and so contained several specimans of the flood on each of the halos and left the sentinals there to controll them if they were to escape, and the monitors to maintain the rings. and the flood lay dormant for over 100, 000 years untill the covenant awoke them in halo CE It is belived that humans are the children of forerunners as stated by guilty spark 343 in halo CE. And that is it i think sorry i couldnt be more precise i have not yet read ghosts of onyx or contact harvest which contains more key points.