"""
Generate header file with macros defining MicroPython version info.

This script works with Python 2.6, 2.7, 3.3 and 3.4.
"""

from __future__ import print_function

import sys
import os
import datetime
import subprocess

def get_version_info_from_git():
 # Python 2.6 doesn't have check_output, so check for that
 try:
 subprocess.check_output
 subprocess.check_call
 except AttributeError:
 return None

 # Note: git describe doesn't work if no tag is available
 try:
 git_tag = subprocess.check_output(["git", "describe", "--dirty", "--always", "--tags"], stderr=subprocess.STDOUT, universal_newlines=True).strip()
 except subprocess.CalledProcessError as er:
 if er.returncode == 128:
 # git exit code of 128 means no repository found
 return None
 git_tag = ""
 except OSError:
 return None
 try:
 git_hash = subprocess.check_output(["git", "rev-parse", "--short", "HEAD"], stderr=subprocess.STDOUT, universal_newlines=True).strip()
 except subprocess.CalledProcessError:
 git_hash = "unknown"
 except OSError:
 return None

 try:
 # Check if there are any modified files.
 subprocess.check_call(["git", "diff", "--no-ext-diff", "--quiet", "--exit-code"], stderr=subprocess.STDOUT)
 # Check if there are any staged files.
 subprocess.check_call(["git", "diff-index", "--cached", "--quiet", "HEAD", "--"], stderr=subprocess.STDOUT)
 except subprocess.CalledProcessError:
 git_hash += "-dirty"
 except OSError:
 return None

 # Try to extract MicroPython version from git tag
 ver = git_tag.split("-")[0].split(".")

 return git_tag, git_hash, ver

def get_version_info_from_docs_conf():
 with open(os.path.join(os.path.dirname(sys.argv[0]), "..", "conf.py")) as f:
 for line in f:
 if line.startswith("version = release = '"):
 ver = line.strip().split(" = ")[2].strip("'")
 git_tag = "v" + ver
 ver = ver.split(".")
 if len(ver) == 2:
 ver.append("0")
 return git_tag, "<no hash>", ver
 return None

def make_version_header(filename):
 # Get version info using git, with fallback to docs/conf.py
 info = get_version_info_from_git()
 if info is None:
 info = get_version_info_from_docs_conf()

 git_tag, git_hash, ver = info
 if len(ver) < 3:
 ver = ("0", "0", "0")
 version_string = git_hash
 else:
 version_string = ".".join(ver)

 # Generate the file with the git and version info
 file_data = """\
// This file was generated by py/makeversionhdr.py
#define MICROPY_GIT_TAG "%s"
#define MICROPY_GIT_HASH "%s"
#define MICROPY_BUILD_DATE "%s"
#define MICROPY_VERSION_MAJOR (%s)
#define MICROPY_VERSION_MINOR (%s)
#define MICROPY_VERSION_MICRO (%s)
#define MICROPY_VERSION_STRING "%s"
#define MICROPY_FULL_VERSION_INFO ("Adafruit CircuitPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE "; " MICROPY_HW_BOARD_NAME " with " MICROPY_HW_MCU_NAME)
""" % (git_tag, git_hash, datetime.date.today().strftime("%Y-%m-%d"),
 ver[0].replace('v', ''), ver[1], ver[2], version_string)

 # Check if the file contents changed from last time
 write_file = True
 if os.path.isfile(filename):
 with open(filename, 'r') as f:
 existing_data = f.read()
 if existing_data == file_data:
 write_file = False

 # Only write the file if we need to
 if write_file:
 with open(filename, 'w') as f:
 f.write(file_data)

if __name__ == "__main__":
 make_version_header(sys.argv[1])