#!/usr/bin/env python3
'''
Takes input FASM and outputs optionally canonical FASM.
'''

import os
import fasm
from prjxray import db

def process_fasm(db_root, fasm_file, canonical):
    database = db.Database(db_root)
    grid = database.grid()

    for fasm_line in fasm.parse_fasm_filename(fasm_file):
        if not fasm_line.set_feature:
            if not canonical:
                yield fasm_line

        for feature in fasm.canonical_features(fasm_line.set_feature):
            parts = feature.feature.split('.')
            tile = parts[0]


            gridinfo = grid.gridinfo_at_tilename(tile)
            tile_segbits = database.get_tile_segbits(gridinfo.tile_type)

            address = 0
            if feature.start is not None:
                address = feature.start

            feature_name = '{}.{}'.format(gridinfo.tile_type, '.'.join(parts[1:]))

            # Convert feature to bits.  If no bits are set, feature is
            # psuedo pip, and should not be output from canonical FASM.
            bits = tuple(tile_segbits.feature_to_bits(feature_name, address=address))
            if len(bits) == 0 and canonical:
                continue

            # In canonical output, only output the canonical features.
            if canonical:
                yield fasm.FasmLine(
                        set_feature=feature,
                        annotations=None,
                        comment=None,
                        )

        # If not in canonical mode, output original FASM line
        if not canonical:
            yield fasm_line


def run(db_root, fasm_file, canonical):
    print(fasm.fasm_tuple_to_string(
        process_fasm(db_root, fasm_file, canonical),
        canonical=canonical))

def main():
    import argparse

    parser = argparse.ArgumentParser(
        description='Read FASM file, check against database, and output optionally canonical FASM.')

    database_dir = os.getenv("XRAY_DATABASE_DIR")
    database = os.getenv("XRAY_DATABASE")
    db_root_kwargs = {}
    if database_dir is None or database is None:
        db_root_kwargs['required'] = True
    else:
        db_root_kwargs['required'] = False
        db_root_kwargs['default'] = os.path.join(database_dir, database)

    parser.add_argument(
        '--db_root', help="Database root.", **db_root_kwargs)
    parser.add_argument('fasm_file', help='Input FASM file')
    parser.add_argument('--canonical', help='Output canonical bitstream.',
            action='store_true')
    args = parser.parse_args()

    run(args.db_root, args.fasm_file, args.canonical)

if __name__ == '__main__':
    main()