import json
from pathlib import Path
from . import RawFileReader


class RawFile:
    """
    Generic Raw File reader. Picks up settings from .json master file
    Currently supports: Moench03 =)
    """
    def __init__(self, fname):
        self.findex = 0
        self.fname = fname
        fname = Path(fname)
        if fname.suffix != '.json':
            raise ValueError("Need a master file in json format")
        
        with open(fname) as f:
            self.master = json.load(f)

        #Figure out which file to open
        if self.master['Detector Type'] == 'Moench' and self.master['Analog Samples'] == 5000:
            #TODO! pass settings to reader
            self._parse_fname()
            self.reader = RawFileReader(self.data_fname(0,0))
        else:
            raise ValueError('unsupported file')

    def _parse_fname(self):
        try:
            base, _, run_id = self.fname.stem.rsplit("_", 2)
            self.base = self.fname.parent / base
            self.run_id = int(run_id)
        except:
            raise ValueError(f"Could not parse master file name: {self.fname}")

    def data_fname(self, i, findex=0):
            return Path(f"{self.base}_d{i}_f{findex}_{self.run_id}.raw")


    def read(self):
        return self.reader.read()
    
    # Support iteration
    def __iter__(self):
        return self
    
    def __next__(self):
        frame = self.reader.read()
        if frame.shape[0] == 0:
            raise StopIteration
    
    # Support with statement
    def __enter__(self):
        return self
    
    def __exit__(self, exception_type, exception_value, traceback):
        pass