Project expense calculator in django admin

I need a django models and django modeladmin views that can handle the folowing tasks:

- one use can own multiple projects
- a user can also be part of another projects
- a project can accept as shareholders multiple users all adding up to 100.00 shares of that project
- the project owner is already added as a project shareholder
- each user can see the projects that is a shareholder of or that it owns
- each user can add costs to a specific project
- when calculating the balance of the project each user should pay the amount of his shares for example if i add 100€ to a project and the project has 2 shareholders 50-50 each then i should’ve added only 50 and i would have a balance of +50€ and the other shareholder should have the balance of -50€ the project should have a total cost of 100€
- a user should be able to make a payment directly to other shareholders and then the balance should be updated accordingly in the above example if user 2 that has -50€ balance were to pay to user 1 50€ then both balances should be 0
- if an expense is added to a project then when a profit is added to the project the profit eill decrease all costs and expenses from that
- each transaction should have m2m tags describing the type of transaction example : employees, space rent, gas and so on, the tags are freely available and most used tags will be shown first
- all operations should be made in the django admin interface
- on the dashboard of each user there will be a few charts regarding each project profit