Discussion: Structure of parameters

[DominicOram]

As a developer I would like it to be easier to manage the internal and external parameters for plans. At the moment there are a number of issues with them such as:

• There is a large amount of boilerplate
• We're providing many parameters the plans might not need

Acceptance Criteria

• We collectively write down the pros/cons of how we're managing this
• We have a meeting to discuss
• In the meeting a new architecture is created and documented
• New tickets are made for implementation

[DominicOram]

• We want the conversion between parameter types to be explicit, not based on magic string key interpretation
  Pseudo code:

class DiffractionExperiment(Model):
    visit: str
	file_name: str
	exposure_time_s: float
	comment: str = ""
	detector_distance_mm: float = None	

    def detector_params() -> DetectorParams:
	   abstract()
	
	def ispyb_params() -> IspybParams: #Soon to remove
	   abstract()

class ThingWithScan(Model):
	def scan_points() -> ScanSpec: 
	   abstract()

class CommonGrid(DiffractionExperiment):
	grid_width_um = GRID_SCAN_WIDTH
	exposure_time_s: float = GRID_SCAN_EXPOSURE_TIME
	use_roi_mode: bool = GRID_SCAN_USE_ROI
	transmission_frac: float = 1
	   
class GridScanWithEdgeDetect(CommonGrid):
	demand_energy_ev: float = None
	omega_start: float = None

class GridScan(CommonGrid, ThingWithScan):
	demand_energy_ev: float = None
	omega_start_deg: float = None
	x_step_size_um: float = APERTURE_SIZE
	y_step_size_um: float = APERTURE_SIZE
	z_step_size_um: float = APERTURE_SIZE
	
	x_steps: int
	y_steps: int
	z_steps: int
	
	x_start_um: float
	y1_start_um: float
	y2_start_um: float
	z1_start_um: float
	z2_start_um: float

    def FGS_params() -> FGSParams:
	    ...

class PinTipCentreThenXrayCentre(CommonGrid, DiffractionExperiment):
    omega_start_deg: float = None
	tip_offset_um: float = 0
	
class RotationScan(DiffractionExperiment, ThingWithScan):
    rotation_axis: Enum = "omega"
	omega_start_deg: float = None
	rotation_angle_deg: float
	rotation_increment_deg: float
	rotation_direction: Enum
	x_start_um: float = None
	y_start_um: float = None
	z_start_um: float = None
	transmission_frac : float
	
class RobotLoadThenCentre(CommonGrid, DiffractionExperiment):
	demand_energy_ev: float = None
	sample_puck: int
	sample_pin: int
	omega_start_deg:float = None
	

# Doesn't yet exist but will look something like this
class DoOneUDC(DiffractionExperiment, CommonGrid):
	""" Diffraction data is for grids at start"""
	demand_energy_ev: float = None
	rotation_exposure_s: float
	rotation_axis: Enum = "omega"
	rotation_angle_deg: float
	rotation_increment_deg: float
	rotation_direction: Enum
	sample_id: int # Will be used to work out puck/pin

[dperl-dls]

Now we have agreed on a model, new tracking issue for implementing changes: #1275