Entities implementation (#14)

* first ideas for entities

* first ideas for entities

* first ideas for entities

* clean code

* clean code

src/clinicaio/models/entity.py

@@ -0,0 +1,215 @@
+
+
+from collections import UserString
+from typing import Union, Optional
+from pathlib import Path 
+from .enum import SUVRReferenceRegions, Tracer, AnatMRISuffix, PETSuffix, FMapSuffix, Modality, Extension
+from enum import Enum
+from dataclasses import dataclass
+# questions: dependance à Pydantic ??
+
+
+class Label(UserString):
+    def __init__(self, value: Union[str, Enum]):
+        super().__init__(self.validate(value))
+
+    @classmethod
+    def validate(cls, value: Union[str, Enum]) -> str:
+        if isinstance(value, Enum):
+            return value.value
+        elif isinstance(value, str) and value.isalnum():
+            return value
+        raise ValueError(
+            f"Label '{value}' is not a valid BIDS label: it must be string composed only by letters and/or numbers."
+        )
+
+class Index(UserString):
+
+    def __init__(self, value: int, length_as_string: int = 1):
+        super().__init__(self.validate(value, length_as_string))
+
+    @classmethod
+    def validate(cls, value: int, length_as_string: int) -> str:
+        if not isinstance(value, int):
+            try:
+                value = int(value)
+            except TypeError as exc:
+                raise ValueError(
+                    f"Index '{value}' is not a valid BIDS index: it must be a non-negative integer."
+                ) from exc
+
+        return str(value).zfill(length_as_string)
+
+
+
+class Entity:
+    key: Label
+    value : Union[Label, Index]
+
+    def __str__(self) -> str:
+        return f"{self.key}-{self.value}"
+
+
+# BIDS Entities
+
+class SubjectEntity(Entity):
+    """
+    A person or animal participating in the study.
+    """
+    key = Label("sub")
+
+    def __init__(self, value: str):
+        self.value = Label(value)
+
+
+class SessionEntity(Entity):
+    """
+    A logical grouping of neuroimaging and behavioral data consistent across subjects. 
+    Session can (but doesn't have to) be synonymous to a visit in a longitudinal study. 
+    In general, subjects will stay in the scanner during one session. 
+    However, for example, if a subject has to leave the scanner room and then be re-positioned 
+    on the scanner bed, the set of MRI acquisitions will still be considered as a session 
+    and match sessions acquired in other subjects. Similarly, in situations where different 
+    data types are obtained over several visits (for example fMRI on one day followed by DWI 
+    the day after) those can be grouped in one session.
+
+    Defining multiple sessions is appropriate when several identical or similar data 
+    acquisitions are planned and performed on all -or most- subjects, often in the 
+    case of some intervention between sessions (for example, training).
+    """
+    key = Label("ses")
+
+    def __init__(self, value: str):
+        self.value = Label(value)
+
+
+class AcquisitionEntity(Entity):
+    """
+    The acq-<label> entity corresponds to a custom label the user MAY use to distinguish a different 
+    set of parameters used for acquiring the same modality.
+
+    For example, this should be used when a study includes two T1w images - one full brain low 
+    resolution and one restricted field of view but high resolution. In such case two files 
+    could have the following names: sub-01_acq-highres_T1w.nii.gz and sub-01_acq-lowres_T1w.nii.gz; 
+    however, the user is free to choose any other label than highres and lowres as long as they are 
+    consistent across subjects and sessions.
+
+    In case different sequences are used to record the same modality (for example, RARE and FLASH for T1w) 
+    this field can also be used to make that distinction. The level of detail at which the distinction 
+    is made (for example, just between RARE and FLASH, or between RARE, FLASH, and FLASHsubsampled) remains 
+    at the discretion of the researcher.
+    """
+    key = Label("acq")
+    def __init__(self, value: str):
+        self.value = Label(value)
+
+class SpaceEntity(Entity):
+    """
+    The space-<label> entity can be used to indicate the way in which electrode positions are interpreted 
+    (for EEG/MEG/iEEG data) or the spatial reference to which a file has been aligned (for MRI data). 
+    The <label> MUST be taken from one of the modality specific lists in the Coordinate Systems Appendix. 
+    For example, for iEEG data, the restricted keywords listed under iEEG Specific Coordinate Systems are 
+    acceptable for <label>.
+
+    For EEG/MEG/iEEG data, this entity can be applied to raw data, but for other data types, it is restricted to derivative data.
+    """
+
+    key = Label("space")
+
+    def __init__(self, value: str):
+        self.value = Label(value)
+
+class TracerEntity(Entity):
+    """
+    This entity represents the "TracerName" metadata field. 
+    Therefore, if the trc-<label> entity is present in a filename, 
+    "TracerName" MUST be defined in the associated metadata. 
+    Please note that the <label> does not need to match the actual value of the field.
+    """
+    key = Label("trc")
+
+    def __init__(self, value: str):
+        self.value = Label(Tracer(value))
+
+class DescriptionEntity(Entity):
+    """
+    When necessary to distinguish two files that do not otherwise have a distinguishing entity, 
+    the desc-<label> entity SHOULD be used.
+
+    This entity is only applicable to derivative data.
+    """
+    key = Label("desc")
+
+    def __init__(self, value: str):
+        self.value = Label(value) 
+
+
+class ResolutionEntity(Entity):
+    """
+    Resolution of regularly sampled N-dimensional data.
+
+    This entity represents the "Resolution" metadata field. Therefore, if the res-<label> 
+    entity is present in a filename, "Resolution" MUST also be added in the JSON file, 
+    to provide interpretation.
+
+    This entity is only applicable to derivative data.
+
+    """
+    key = Label("res")
+
+    def __init__(self, value: str):
+        self.value = Label(value) 
+
+
+class RunEntity(Entity):
+    """
+    The run-<index> entity is used to distinguish separate data acquisitions with the same 
+    acquisition parameters and (other) entities.
+
+    If several data acquisitions (for example, MRI scans or EEG recordings) with the same acquisition 
+    parameters are acquired in the same session, they MUST be indexed with the run-<index> entity: 
+    _run-1, _run-2, _run-3, and so on (only nonnegative integers are allowed as run indices).
+
+    If different entities apply, such as a different session indicated by ses-<label>, 
+    or different acquisition parameters indicated by acq-<label>, then run is not needed to distinguish 
+    the scans and MAY be omitted.
+    """
+
+    key = Label("run")
+
+    def __init__(self, value: int):
+        self.value = Index(value) 
+
+
+class SuffixEntity(Label):
+    pass
+
+# CAPS Entities
+
+class SUVREntity(Entity):
+    key = Label("suvr")
+    def __init__(self, value: str):
+        self.value = Label(SUVRReferenceRegions(value))
+
+
+@dataclass
+class BIDSPath:
+    subject: SubjectEntity
+    session: SessionEntity
+    modality: Modality
+    entities: Optional[list[Entity]]
+    suffix: Optional[SuffixEntity] # is suffix optional ? 
+    extension: Optional[Extension]
+
+    def get_image(self) -> Path:
+        path_ = Path(str(self.subject)) / str(self.session) / str(self.modality)
+
+        filename = str(self.subject) + "_" + str(self.session) 
+
+        for entity in self.entities:
+            filename += "_" + str(entity)
+
+        filename += f".{(str(self.suffix) if self.suffix else '')}"
+        filename += f".{(str(self.extension) if self.extension else '')}"
+
+        return path_ / filename

src/clinicaio/models/enum.py

@@ -0,0 +1,44 @@
+
+
+from enum import Enum
+
+class SUVRReferenceRegions(str, Enum):
+    """Possible SUVR reference region for pet images in clinicaDL."""
+
+    PONS = "pons"
+    CEREBELLUMPONS = "cerebellumPons"
+    PONS2 = "pons2"
+    CEREBELLUMPONS2 = "cerebellumPons2"
+
+
+class Tracer(str, Enum):
+    """Possible tracer for pet images in clinicaDL."""
+
+    FFDG = "18FFDG"
+    FAV45 = "18FAV45"
+    CPIB = "11CPIB"
+
+class AnatMRISuffix(str, Enum):
+    FLAIR = "FLAIR"
+    T1W = "T1w"
+    T2W = "T2w"
+
+
+class PETSuffix(str, Enum):
+    PET = "pet"
+
+class DWISuffix(str, Enum):
+    DWI = "dwi"
+
+class FMapSuffix(str, Enum):
+    pass
+
+class Modality(str, Enum):
+    pass
+
+
+class Extension(str, Enum):
+    NIFTI = ".nii"
+    NIFTI_GZ = ".nii.gz"
+    DICOM = ".dcm"
+    PT = ".pt"