#!/usr/bin/env python3

import os

"""
mkdir -p /dev/shm/fusefuzz/{r,v}
PYTHONPATH=.. python3 -m copyparty -v /dev/shm/fusefuzz/r::r -i 127.0.0.1
../bin/copyparty-fuse.py /dev/shm/fusefuzz/v http://127.0.0.1:3923/ 2 0
(d="$PWD"; cd /dev/shm/fusefuzz && "$d"/fusefuzz.py)
"""


def main():
    for n in range(5):
        with open(f"r/{n}", "wb") as f:
            f.write(b"h" * n)

    for fsz in range(1024 * 1024 * 2 - 3, 1024 * 1024 * 2 + 3):
        with open("r/f", "wb", fsz) as f:
            f.write(b"\xab" * fsz)

        for rsz in range(62, 66):
            ofslist = [0, 1, 2]
            for n in range(3):
                ofslist.append(fsz - n)
                ofslist.append(fsz - (rsz * 1 + n))
                ofslist.append(fsz - (rsz * 2 + n))

            for ofs0 in ofslist:
                for shift in range(-3, 3):
                    print(f"fsz {fsz} rsz {rsz} ofs {ofs0} shift {shift}")
                    ofs = ofs0
                    if ofs < 0 or ofs >= fsz:
                        continue

                    for n in range(1, 3):
                        with open(f"v/{n}", "rb") as f:
                            f.read()

                    prev_ofs = -99
                    with open("r/f", "rb", rsz) as rf:
                        with open("v/f", "rb", rsz) as vf:
                            while True:
                                ofs += shift
                                if ofs < 0 or ofs > fsz or ofs == prev_ofs:
                                    break

                                prev_ofs = ofs

                                if ofs != rf.tell():
                                    rf.seek(ofs)
                                    vf.seek(ofs)

                                rb = rf.read(rsz)
                                vb = vf.read(rsz)

                                print(
                                    f"fsz {fsz} rsz {rsz} ofs {ofs0} shift {shift} ofs {ofs} = {len(rb)}"
                                )

                                if rb != vb:
                                    raise Exception(f"{len(rb)} != {len(vb)}")

                                if not rb:
                                    break

                                ofs += len(rb)


if __name__ == "__main__":
    main()