#!/usr/bin/env python
#
# Python script to generate ReSTructured Text .inc snippets
# with version-based content for this IDF version

import subprocess
import os
import sys
import re

TEMPLATES = {
    "en" : {
        "git-clone" : {
            "template" : """
To obtain a local copy: open terminal, navigate to the directory you want to put ESP-IDF, and clone the repository using ``git clone`` command::

    cd ~/esp
    git clone %(clone_args)s--recursive https://github.com/espressif/esp-idf.git

ESP-IDF will be downloaded into ``~/esp/esp-idf``.

.. note::

    %(extra_note)s

.. note::

    %(zipfile_note)s
"""
            ,"master" : 'This command will clone the master branch, which has the latest development ("bleeding edge") version of ESP-IDF. It is fully functional and updated on weekly basis with the most recent features and bugfixes.'
            ,"branch" : 'The ``git clone`` option ``-b %s`` tells git to clone the %s in the ESP-IDF repository corresponding to this version of the documentation.'
            ,"zipfile" : {
                "stable" : 'As a fallback, it is also possible to download a zip file of this stable release from the `Releases page`_. Do not download the "Source code" zip file(s) generated automatically by GitHub, they do not work with ESP-IDF.'
                ,"unstable" : 'GitHub\'s "Download zip file" feature does not work with ESP-IDF, a ``git clone`` is required. As a fallback, `Stable version`_ can be installed without Git.'
                },  # zipfile
            },  # git-clone
        "version-note" : {
            "master" : """
.. note::
     This is documentation for the master branch (latest version) of ESP-IDF. This version is under continual development. `Stable version`_ documentation is available, as well as other :doc:`/versions`.
"""
            ,"stable" : """
.. note::
     This is documentation for stable version %s of ESP-IDF. Other :doc:`/versions` are also available.
"""
            ,"branch" : """
.. note::
     This is documentation for %s ``%s`` of ESP-IDF. Other :doc:`/versions` are also available.
"""
            },  # version-note
    }, # en
}


def main():
    if len(sys.argv) != 3:
        print("Usage: gen-git-clone.py <language> <output file path>")
        sys.exit(1)

    language = sys.argv[1]
    out_dir = sys.argv[2]
    if not os.path.exists(out_dir):
        print("Output directory %s not found" % out_dir)
        sys.exit(1)

    template = TEMPLATES[language]

    version, ver_type, is_stable = get_version()

    write_git_clone_inc(template["git-clone"], out_dir, version, ver_type, is_stable)
    write_version_note(template["version-note"], out_dir, version, ver_type, is_stable)
    print("Done")


def write_git_clone_inc(template, out_dir, version, ver_type, is_stable):
    zipfile = template["zipfile"]
    if version == "master":
        args = {
            "clone_args" : "",
            "extra_note" : template["master"],
            "zipfile_note" : zipfile["unstable"]
        }
    else:
        args = {
            "clone_args" : "-b %s " % version,
            "extra_note" : template["branch"] % (version, ver_type),
            "zipfile_note" : zipfile["stable"] if is_stable else zipfile["unstable"]
        }
    out_file = os.path.join(out_dir, "git-clone.inc")
    with open(out_file, "w") as f:
        f.write(template["template"] % args)
    print("%s written" % out_file)


def write_version_note(template, out_dir, version, ver_type, is_stable):
    if version == "master":
        content = template["master"]
    elif ver_type == "tag" and is_stable:
        content = template["stable"] % version
    else:
        content = template["branch"] % (ver_type, version)
    out_file = os.path.join(out_dir, "version-note.inc")
    with open(out_file, "w") as f:
        f.write(content)
    print("%s written" % out_file)


def get_version():
    """
    Returns a tuple of (name of branch/tag, type branch/tag, is_stable)
    """
    # Trust what RTD says our version is, if it is set
    version = os.environ.get("READTHEDOCS_VERSION", None)
    if version == "latest":
        return ("master", "branch", False)

    # Otherwise, use git to look for a tag
    try:
        tag = subprocess.check_output(["git", "describe", "--tags", "--exact-match"]).strip()
        is_stable = re.match(r"v[0-9\.]+$", tag) is not None
        return (tag, "tag", is_stable)
    except subprocess.CalledProcessError:
        pass

    # No tag, look for a branch
    refs = subprocess.check_output(["git", "for-each-ref", "--points-at", "HEAD", "--format", "%(refname)"])
    print("refs:\n%s" % refs)
    refs = refs.split("\n")
    # Note: this looks for branches in 'origin' because GitLab CI doesn't check out a local branch
    branches = [ r.replace("refs/remotes/origin/","").strip() for r in refs if r.startswith("refs/remotes/origin/") ]
    if len(branches) == 0:
        # last resort, return the commit (may happen on Gitlab CI sometimes, unclear why)
        return (subprocess.check_output(["git", "rev-parse", "--short", "HEAD"]).strip(), "commit", False)
    if "master" in branches:
        return ("master", "branch", False)
    else:
        return (branches[0], "branch", False)  # take whatever the first branch is

if __name__ == "__main__":
    main()