#!/bin/env python3
import re
import sys
import os
import subprocess
import datetime
import shutil

# Example invocation:
# python3 patchport.py 839 8.3.9g
# /home/ave/apks/com.discord-841/ /home/ave/cutthecordrepo/

from_versioncode = sys.argv[1]
from_versionname = sys.argv[2]
apk_folder = sys.argv[3]
cutthecord_folder = sys.argv[4]
debug = False
tmp_folder = "/tmp/patchport"


def modify_patch(patch_name, patch_path):
    with open(patch_path) as f:
        patch_content = f.read()

    if patch_name in ["branding", "customversion"]:
        patch_content = patch_content.replace(from_versioncode, to_versioncode)
        patch_content = patch_content.replace(from_versionname, to_versionname)

    if patch_name == "notrack":
        # TODO: There's a risk here that we'll replace the nulled value
        from_crashlytics_id = re_crashlytics.findall(patch_content)[0]
        patch_content = patch_content.replace(from_crashlytics_id,
                                              to_crashlytics_id)
    return patch_content


def fix_offset(patch_contents):
    # OH GOD OH FUCK
    shutil.rmtree(tmp_folder, ignore_errors=True)
    shutil.copytree(apk_folder, tmp_folder)
    subprocess.run("patch -p1 --no-backup-if-mismatch --force",
                   shell=True, input=patch_contents, text=True,
                   cwd=tmp_folder)
    out = subprocess.run(f"diff -crB {apk_folder} {tmp_folder}",
                         shell=True, input=patch_contents, text=True,
                         cwd=tmp_folder, capture_output=True)
    shutil.rmtree(tmp_folder, ignore_errors=True)
    return out.stdout


re_versioncode = re.compile(r'platformBuildVersionCode="([0-9]+)"')
re_versionname = re.compile(r'platformBuildVersionName="([0-9a-z.]+)"')
re_releasedate = re.compile(r'released on ([0-9]{4}-[0-9]{2}-[0-9]{2})')
re_crashlytics = re.compile(r'com\.crashlytics\.android\.build_id">([a-z0-9]'
                            r'{8}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}-'
                            r'[a-z0-9]{12})</string>')


# Get version code and name
with open(os.path.join(apk_folder, "AndroidManifest.xml")) as f:
    file_contents = f.read()
    to_versioncode = re_versioncode.findall(file_contents)[0]
    to_versionname = re_versionname.findall(file_contents)[0]

# Get crashlytics build ID
with open(os.path.join(apk_folder, "res", "values", "strings.xml")) as f:
    file_contents = f.read()
    to_crashlytics_id = re_crashlytics.findall(file_contents)[0]


failures = []

for patch in os.listdir(os.path.join(cutthecord_folder, "patches")):
    patch_path = os.path.join(cutthecord_folder, "patches", patch,
                              f"{from_versioncode}.patch")
    out_path = os.path.join(cutthecord_folder, "patches", patch,
                            f"{to_versioncode}.patch")
    readme_path = os.path.join(cutthecord_folder, "patches", patch, "README.md")

    # Check if patch exists for from_version, if it doesn't, warn user
    if not os.path.isfile(patch_path):
        # Don't warn on instructional patches
        if patch not in ["customfont", "customring",
                         "bettertm", "bettertmlight"]:
            print(f"SKIPPED: No {from_versionname} version found for {patch}.")
        continue

    # Get a modified version of the patch
    patch_contents = modify_patch(patch, patch_path)

    # Pass the new patch to patch command and get it to attempt to patch
    out = subprocess.run("patch -p1 --dry-run --force", shell=True,
                         cwd=apk_folder, input=patch_contents, text=True,
                         capture_output=True)

    # Check for issues
    if "FAILED" in out.stdout:
        print(f"FAILED: {patch} failed, please fix by hand.")
        failures.append(patch)
        out_path += "-failed"
    elif "offset" in out.stdout:
        patch_contents = fix_offset(patch_contents)
        print(f"WARNING: {patch} has offsets which were auto corrected.")

    if debug:
        print(out.stdout)

    # Add supported version to readme of that patch, hacky
    # https://stackoverflow.com/a/35130508/3286892
    with open(readme_path, 'r') as f:
        readme_text = f.read().replace(f'- {from_versionname}',
                                       f'- {from_versionname}\n'
                                       f'- {to_versionname}')
    with open(readme_path, "w") as f:
        f.write(readme_text)

    # Save ported patch
    with open(out_path, "w") as f:
        f.write(patch_contents)

    print(f"PORTED: {patch} was successfully ported.")

if failures:
    print(f"Port complete. Following patches failed: {', '.join(failures)}")
else:
    ctcreadme_path = os.path.join(cutthecord_folder, "README.md")
    # TODO: can we pull the correct date from distok?
    out_datestamp = datetime.datetime.utcnow().strftime("%Y-%m-%d")
    # Update readme with latest version, hacky
    # https://stackoverflow.com/a/35130508/3286892
    with open(ctcreadme_path, 'r') as f:
        ctcr_text = f.read().replace(f'{from_versionname} ({from_versioncode})',
                                     f'{to_versionname} ({to_versioncode})')
    in_datestamp = re_releasedate.findall(ctcr_text)[0]
    ctcr_text = ctcr_text.replace(in_datestamp, out_datestamp)
    with open(ctcreadme_path, "w") as f:
        f.write(ctcr_text)

    print("Port complete. All patches completed successfully. "
          "README.md was updated.")