# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
#
# Copyright (c) 2013, Intel Corporation.
# All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# DESCRIPTION

# This module implements the image creation engine used by 'wic' to
# create images.  The engine parses through the OpenEmbedded kickstart
# (wks) file specified and generates images that can then be directly
# written onto media.
#
# AUTHORS
# Tom Zanussi <tom.zanussi (at] linux.intel.com>
#

import os
import sys
from abc import ABCMeta, abstractmethod
import shlex
import json
import subprocess
import shutil

import os, sys, errno
from wic import msger, creator
from wic.utils import cmdln, misc, errors
from wic.conf import configmgr
from wic.plugin import pluginmgr
from wic.__version__ import VERSION
from wic.utils.oe import misc


def verify_build_env():
    """
    Verify that the build environment is sane.

    Returns True if it is, false otherwise
    """
    try:
        builddir = os.environ["BUILDDIR"]
    except KeyError:
        print "BUILDDIR not found, exiting. (Did you forget to source oe-init-build-env?)"
        sys.exit(1)

    return True


CANNED_IMAGE_DIR = "lib/image/canned-wks" # relative to scripts
SCRIPTS_CANNED_IMAGE_DIR = "scripts/" + CANNED_IMAGE_DIR

def build_canned_image_list(dl):
    layers_path = misc.get_bitbake_var("BBLAYERS")
    canned_wks_layer_dirs = []

    if layers_path is not None:
        for layer_path in layers_path.split():
            path = os.path.join(layer_path, SCRIPTS_CANNED_IMAGE_DIR)
            canned_wks_layer_dirs.append(path)

    path = os.path.join(dl, CANNED_IMAGE_DIR)
    canned_wks_layer_dirs.append(path)

    return canned_wks_layer_dirs

def find_canned_image(scripts_path, wks_file):
    """
    Find a .wks file with the given name in the canned files dir.

    Return False if not found
    """
    layers_canned_wks_dir = build_canned_image_list(scripts_path)

    for canned_wks_dir in layers_canned_wks_dir:
        for root, dirs, files in os.walk(canned_wks_dir):
            for file in files:
                if file.endswith("~") or file.endswith("#"):
                    continue
                if file.endswith(".wks") and wks_file + ".wks" == file:
                    fullpath = os.path.join(canned_wks_dir, file)
                    return fullpath
    return None


def list_canned_images(scripts_path):
    """
    List the .wks files in the canned image dir, minus the extension.
    """
    layers_canned_wks_dir = build_canned_image_list(scripts_path)

    for canned_wks_dir in layers_canned_wks_dir:
        for root, dirs, files in os.walk(canned_wks_dir):
            for file in files:
                if file.endswith("~") or file.endswith("#"):
                    continue
                if file.endswith(".wks"):
                    fullpath = os.path.join(canned_wks_dir, file)
                    f = open(fullpath, "r")
                    lines = f.readlines()
                    for line in lines:
                        desc = ""
                        idx = line.find("short-description:")
                        if idx != -1:
                            desc = line[idx + len("short-description:"):].strip()
                            break
                    basename = os.path.splitext(file)[0]
                    print "  %s\t\t%s" % (basename.ljust(30), desc)


def list_canned_image_help(scripts_path, fullpath):
    """
    List the help and params in the specified canned image.
    """
    f = open(fullpath, "r")
    lines = f.readlines()
    found = False
    for line in lines:
        if not found:
            idx = line.find("long-description:")
            if idx != -1:
                print
                print line[idx + len("long-description:"):].strip()
                found = True
            continue
        if not line.strip():
            break
        idx = line.find("#")
        if idx != -1:
            print line[idx + len("#:"):].rstrip()
        else:
            break


def list_source_plugins():
    """
    List the available source plugins i.e. plugins available for --source.
    """
    plugins = pluginmgr.get_source_plugins()

    for plugin in plugins:
        print "  %s" % plugin


def wic_create(wks_file, rootfs_dir, bootimg_dir, kernel_dir,
               native_sysroot, scripts_path, image_output_dir,
               compressor, debug):
    """Create image

    wks_file - user-defined OE kickstart file
    rootfs_dir - absolute path to the build's /rootfs dir
    bootimg_dir - absolute path to the build's boot artifacts directory
    kernel_dir - absolute path to the build's kernel directory
    native_sysroot - absolute path to the build's native sysroots dir
    scripts_path - absolute path to /scripts dir
    image_output_dir - dirname to create for image
    compressor - compressor utility to compress the image

    Normally, the values for the build artifacts values are determined
    by 'wic -e' from the output of the 'bitbake -e' command given an
    image name e.g. 'core-image-minimal' and a given machine set in
    local.conf.  If that's the case, the variables get the following
    values from the output of 'bitbake -e':

    rootfs_dir:        IMAGE_ROOTFS
    kernel_dir:        DEPLOY_DIR_IMAGE
    native_sysroot:    STAGING_DIR_NATIVE

    In the above case, bootimg_dir remains unset and the
    plugin-specific image creation code is responsible for finding the
    bootimg artifacts.

    In the case where the values are passed in explicitly i.e 'wic -e'
    is not used but rather the individual 'wic' options are used to
    explicitly specify these values.
    """
    try:
        oe_builddir = os.environ["BUILDDIR"]
    except KeyError:
        print "BUILDDIR not found, exiting. (Did you forget to source oe-init-build-env?)"
        sys.exit(1)

    if debug:
        msger.set_loglevel('debug')

    cr = creator.Creator()

    cr.main(["direct", native_sysroot, kernel_dir, bootimg_dir, rootfs_dir,
             wks_file, image_output_dir, oe_builddir, compressor or ""])

    print "\nThe image(s) were created using OE kickstart file:\n  %s" % wks_file


def wic_list(args, scripts_path, properties_file):
    """
    Print the complete list of properties defined by the image, or the
    possible values for a particular image property.
    """
    if len(args) < 1:
        return False

    if len(args) == 1:
        if args[0] == "images":
            list_canned_images(scripts_path)
            return True
        elif args[0] == "source-plugins":
            list_source_plugins()
            return True
        elif args[0] == "properties":
            return True
        else:
            return False

    if len(args) == 2:
        if args[0] == "properties":
            wks_file = args[1]
            print "print properties contained in wks file: %s" % wks_file
            return True
        elif args[0] == "property":
            print "print property values for property: %s" % args[1]
            return True
        elif args[1] == "help":
            wks_file = args[0]
            fullpath = find_canned_image(scripts_path, wks_file)
            if not fullpath:
                print "No image named %s found, exiting.  (Use 'wic list images' to list available images, or specify a fully-qualified OE kickstart (.wks) filename)\n" % wks_file
                sys.exit(1)
            list_canned_image_help(scripts_path, fullpath)
            return True
        else:
            return False

    return False