#!/usr/bin/env python3
#
#    build-command-template: converts new style command definitions in XML
#      to the old style (bunch of dirs and node.def's) command templates
#
#    Copyright (C) 2017 VyOS maintainers <maintainers@vyos.net>
#
#    This library is free software; you can redistribute it and/or
#    modify it under the terms of the GNU Lesser General Public
#    License as published by the Free Software Foundation; either
#    version 2.1 of the License, or (at your option) any later version.
#
#    This library 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
#    Lesser General Public License for more details.
#
#    You should have received a copy of the GNU Lesser General Public
#    License along with this library; if not, write to the Free Software
#    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
#    USA

import sys
import os
import copy
import functools

from lxml import etree as ET


## Get arguments

if len(sys.argv) < 4:
    print("Usage: {0} <interface definition file> <schema file> <output directory>".format(sys.argv[0]))
    sys.exit(1)

input_file = sys.argv[1]
schema_file = sys.argv[2]
output_dir = sys.argv[3]

## Load and validate the inputs

try:
    xml = ET.parse(input_file)
except Exception as e:
    print("Failed to load interface definition file {0}".format(input_file))
    print(e)
    sys.exit(1)

try:
    relaxng_xml = ET.parse(schema_file)
    validator = ET.RelaxNG(relaxng_xml)

    if not validator.validate(xml):
        print(validator.error_log)
        print("Interface definition file {0} does not match the schema!".format(input_file))
        sys.exit(1)
except Exception as e:
    print("Failed to load the XML schema {0}".format(schema_file))
    print(e)
    sys.exit(1)

if not os.access(output_dir, os.W_OK):
    print("The output directory {0} is not writeable".format(output_dir))
    sys.exit(1)

## If we got this far, everything must be ok and we can convert the file

def make_path(l):
    return(functools.reduce(os.path.join, l))

def get_properties(p):
    props = {}

    if p is None:
        return props

    # Get the help string
    try:
        props["help"] = p.find("help").text
    except:
        pass

    # Get value help strings
    try:
        vhe = p.findall("valueHelp")
        vh = []
        for v in vhe:
            vh.append( (v.find("format").text, v.find("description").text) )
        props["val_help"] = vh
    except:
        props["val_help"] = []

    # Get priority
    try:
        props["priority"] = p.find("priority").text
    except:
        pass

    # Get "multi"
    if p.find("multi") is not None:
        props["multi"] = True

    return props

def make_node_def(props):
    # XXX: replace with a template processor if it grows
    #      out of control

    node_def = ""

    if "tag" in props:
        node_def += "tag:\n"

    if "type" in props:
        node_def += "type: {0}\n".format(props["type"])

    if "multi" in props:
        node_def += "multi:\n"

    if "priority" in props:
        node_def += "priority: {0}\n".format(props["priority"])

    if "help" in props:
        node_def += "help: {0}\n".format(props["help"])

    if "val_help" in props:
        for v in props["val_help"]:
            node_def += "val_help: {0}; {1}\n".format(v[0], v[1])

    if "owner" in props:
        node_def += "end: {0}\n".format(props["owner"])

    return node_def


def process_node(n, tmpl_dir):
    # Avoid mangling the path from the outer call
    my_tmpl_dir = copy.copy(tmpl_dir)

    props_elem = n.find("properties")
    children = n.find("children")

    name = n.get("name")
    owner = n.get("owner")
    node_type = n.tag

    my_tmpl_dir.append(name)
    os.makedirs(make_path(my_tmpl_dir), exist_ok=True)

    props = get_properties(props_elem)
    if owner:
        props["owner"] = owner
    # Type should not be set for non-tag, non-leaf nodes
    if node_type != "node":
        props["type"] = "txt"
    if node_type == "tagNode":
        props["tag"] = "True"
    

    with open(os.path.join(make_path(my_tmpl_dir), "node.def"), "w") as f:
        f.write(make_node_def(props))


    if node_type == "node":
        inner_nodes = children.iterfind("*")
        for inner_n in inner_nodes:
            process_node(inner_n, my_tmpl_dir)
    if node_type == "tagNode":
        my_tmpl_dir.append("node.tag")
        os.makedirs(make_path(my_tmpl_dir), exist_ok=True)
        inner_nodes = children.iterfind("*")
        for inner_n in inner_nodes:
            process_node(inner_n, my_tmpl_dir)
    else:
        # This is a leaf node
        pass
        

root = xml.getroot()

nodes = root.iterfind("*")
for n in nodes:
    process_node(n, [output_dir])