#!/usr/bin/env python3
"""
Python script to parse and clone a repo
in order for asciidoctor to be able to access included files

Doesn't overwrite folder if it already exists.

Cache asciidoctor result for performance.

Parameters : 
in : a relative path as given by GITEA_PREFIX_SRC (https://docs.gitea.io/en-us/config-cheat-sheet/#markup-markup)
return : The name of the folder containing the cloned repo
"""

import sys
import subprocess
import os
import zlib
import shutil

if(len(sys.argv) != 4):
    sys.exit("wrong number of args <source repo> <prefix> <cache path>") # wrong number of args

# Prefix for the path where repository are saved, can be an url
PATH_PREFIX = sys.argv[2]
# Prefix for where we will clone the repos
CACHE_FOLDER_PATH = sys.argv[3]
# Filename for the input buffer
INPUT_BUFFER_FILENAME = "input_buff"

# get repo name (/username/repo)
repo_path = sys.argv[1].split('/',3)
if(len(repo_path)<2):
    sys.exit("Wrong path format passed")

repo_name = "/".join([CACHE_FOLDER_PATH,repo_path[2]])
repo_path = "/".join(repo_path[:3])
repo_path = PATH_PREFIX + repo_path
repo_path = repo_path.lower()

if not os.path.isdir(CACHE_FOLDER_PATH):
    os.makedirs(CACHE_FOLDER_PATH)

if not os.path.isdir(repo_name):
    subprocess.run(["git", "clone", repo_path, repo_name], check=True, stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT)

inputBufferPath = "/".join([repo_name,INPUT_BUFFER_FILENAME])

# get input hash and save stdin to file
inHash = 0
b  = bytearray(128*1024)
mv = memoryview(b)
with open(inputBufferPath,'wb') as out:
    while n := sys.stdin.buffer.readinto(mv):
        inHash = zlib.adler32(mv[:n],inHash)
        out.write(mv[:n])

cachedOutPath = "/".join([repo_name,str(inHash)])

# If not already rendered
if not os.path.isfile(cachedOutPath):
    subprocess.run(["asciidoctor", "-s", "--safe-mode", "server", "-a", "showtitle", "-a", "source-highlighter=rouge", "-a", "rouge-css=style", "-a", "rouge-style=base16.monokai.dark", f"--out-file={str(inHash)}", f"--base-dir={repo_name}", inputBufferPath])

# return rendered(or cached) output to stdout
with open(cachedOutPath, "rb") as f:
    shutil.copyfileobj(f, sys.stdout.buffer)