"""
Manage Perl modules using CPAN

.. versionadded:: 2015.5.0
"""

import logging
import os
import os.path

import salt.utils.files
import salt.utils.path

log = logging.getLogger(__name__)

# Don't shadow built-ins.
__func_alias__ = {"list_": "list"}


def __virtual__():
    """
    Only work on supported POSIX-like systems
    """
    if salt.utils.path.which("cpan"):
        return True
    return (False, "Unable to locate cpan. Make sure it is installed and in the PATH.")


def install(module):
    """
    Install a Perl module from CPAN

    CLI Example:

    .. code-block:: bash

        salt '*' cpan.install Template::Alloy
    """
    ret = {
        "old": None,
        "new": None,
    }

    old_info = show(module)

    cmd = "cpan -i {}".format(module)
    out = __salt__["cmd.run"](cmd)

    if "don't know what it is" in out:
        ret["error"] = "CPAN cannot identify this package"
        return ret

    new_info = show(module)
    ret["old"] = old_info.get("installed version", None)
    ret["new"] = new_info["installed version"]

    return ret


def remove(module, details=False):
    """
    Attempt to remove a Perl module that was installed from CPAN. Because the
    ``cpan`` command doesn't actually support "uninstall"-like functionality,
    this function will attempt to do what it can, with what it has from CPAN.

    Until this function is declared stable, USE AT YOUR OWN RISK!

    CLI Example:

    .. code-block:: bash

        salt '*' cpan.remove Old::Package
    """
    ret = {
        "old": None,
        "new": None,
    }

    info = show(module)
    if "error" in info:
        return {"error": info["error"]}

    version = info.get("installed version", None)
    if version is None:
        return ret

    ret["old"] = version

    if "cpan build dirs" not in info:
        return {"error": "No CPAN data available to use for uninstalling"}

    mod_pathfile = module.replace("::", "/") + ".pm"
    ins_path = info["installed file"].replace(mod_pathfile, "")

    files = []
    for build_dir in info["cpan build dirs"]:
        contents = os.listdir(build_dir)
        if "MANIFEST" not in contents:
            continue
        mfile = os.path.join(build_dir, "MANIFEST")
        with salt.utils.files.fopen(mfile, "r") as fh_:
            for line in fh_.readlines():
                line = salt.utils.stringutils.to_unicode(line)
                if line.startswith("lib/"):
                    files.append(line.replace("lib/", ins_path).strip())

    rm_details = {}
    for file_ in files:
        if file_ in rm_details:
            continue
        log.trace("Removing %s", file_)
        if __salt__["file.remove"](file_):
            rm_details[file_] = "removed"
        else:
            rm_details[file_] = "unable to remove"

    if details:
        ret["details"] = rm_details

    return ret


def list_():
    """
    List installed Perl modules, and the version installed

    CLI Example:

    .. code-block:: bash

        salt '*' cpan.list
    """
    ret = {}
    cmd = "cpan -l"
    out = __salt__["cmd.run"](cmd).splitlines()
    for line in out:
        comps = line.split()
        ret[comps[0]] = comps[1]
    return ret


def show(module):
    """
    Show information about a specific Perl module

    CLI Example:

    .. code-block:: bash

        salt '*' cpan.show Template::Alloy
    """
    ret = {}
    ret["name"] = module

    # This section parses out details from CPAN, if possible
    cmd = "cpan -D {}".format(module)
    out = __salt__["cmd.run"](cmd).splitlines()
    mode = "skip"
    info = []
    for line in out:
        if line.startswith("-------------"):
            mode = "parse"
            continue
        if mode == "skip":
            continue
        info.append(line)

    if len(info) == 6:
        # If the module is not installed, we'll be short a line
        info.insert(2, "")
    if len(info) < 6:
        # This must not be a real package
        ret["error"] = "This package does not seem to exist"
        return ret

    ret["description"] = info[0].strip()
    ret["cpan file"] = info[1].strip()
    if info[2].strip():
        ret["installed file"] = info[2].strip()
    else:
        ret["installed file"] = None
    comps = info[3].split(":")
    if len(comps) > 1:
        ret["installed version"] = comps[1].strip()
    if "installed version" not in ret or not ret["installed version"]:
        ret["installed version"] = None
    comps = info[4].split(":")
    comps = comps[1].split()
    ret["cpan version"] = comps[0].strip()
    ret["author name"] = info[5].strip()
    ret["author email"] = info[6].strip()

    # Check and see if there are cpan build directories
    config = show_config()
    build_dir = config.get("build_dir", None)
    if build_dir is not None:
        ret["cpan build dirs"] = []
        builds = os.listdir(build_dir)
        pfile = module.replace("::", "-")
        for file_ in builds:
            if file_.startswith(pfile):
                ret["cpan build dirs"].append(os.path.join(build_dir, file_))

    return ret


def show_config():
    """
    Return a dict of CPAN configuration values

    CLI Example:

    .. code-block:: bash

        salt '*' cpan.show_config
    """
    ret = {}
    cmd = "cpan -J"
    out = __salt__["cmd.run"](cmd).splitlines()
    for line in out:
        if "=>" not in line:
            # TODO: Some options take up multiple lines, so this doesn't always work
            continue
        comps = line.split("=>")
        key = comps[0].replace("'", "").strip()
        val = comps[1].replace("',", "").replace("'", "").strip()
        ret[key] = val
    return ret
