#!/usr/bin/python3

# Copyright (c) 2010, 2011, 2012, 2013, 2014, 2015, 2020 Nicira, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import getopt
import sys
import xml.dom.minidom

import ovs.json
from ovs.db import error
import ovs.db.schema

from ovs_build_helpers.nroff import block_xml_to_nroff
from ovs_build_helpers.nroff import escape_nroff_literal
from ovs_build_helpers.nroff import text_to_nroff

argv0 = sys.argv[0]


def typeAndConstraintsToNroff(column):
    type = column.type.toEnglish(escape_nroff_literal)
    constraints = column.type.constraintsToEnglish(escape_nroff_literal,
                                                   text_to_nroff)
    if constraints:
        type += ", " + constraints
    if column.unique:
        type += " (must be unique within table)"
    return type


def columnGroupToNroff(table, groupXml, documented_columns):
    introNodes = []
    columnNodes = []
    for node in groupXml.childNodes:
        if (node.nodeType == node.ELEMENT_NODE
            and node.tagName in ('column', 'group')):
            columnNodes += [node]
        else:
            if (columnNodes
                and not (node.nodeType == node.TEXT_NODE
                         and node.data.isspace())):
                raise error.Error(
                    "text follows <column> or <group> inside <group>: %s"
                    % node
                )
            introNodes += [node]

    summary = []
    intro = block_xml_to_nroff(introNodes)
    body = ''
    for node in columnNodes:
        if node.tagName == 'column':
            name = node.attributes['name'].nodeValue
            documented_columns.add(name)
            column = table.columns[name]
            if node.hasAttribute('key'):
                key = node.attributes['key'].nodeValue
                if node.hasAttribute('type'):
                    type_string = node.attributes['type'].nodeValue
                    type_json = ovs.json.from_string(str(type_string))
                    if type(type_json) in (bytes, str):
                        raise error.Error("%s %s:%s has invalid 'type': %s"
                                          % (table.name, name, key, type_json))
                    type_ = ovs.db.types.BaseType.from_json(type_json)
                else:
                    type_ = column.type.value

                nameNroff = "%s : %s" % (name, key)

                if column.type.value:
                    typeNroff = "optional %s" % column.type.value.toEnglish(
                        escape_nroff_literal)
                    if (column.type.value.type == ovs.db.types.StringType and
                        type_.type == ovs.db.types.BooleanType):
                        # This is a little more explicit and helpful than
                        # "containing a boolean"
                        typeNroff += r", either \fBtrue\fR or \fBfalse\fR"
                    else:
                        if type_.type != column.type.value.type:
                            type_english = type_.toEnglish()
                            typeNroff += ", containing "
                            if type_english[0] in 'aeiou':
                                typeNroff += "an %s" % type_english
                            else:
                                typeNroff += "a %s" % type_english
                        constraints = (
                            type_.constraintsToEnglish(escape_nroff_literal,
                                                       text_to_nroff))
                        if constraints:
                            typeNroff += ", %s" % constraints
                else:
                    typeNroff = "none"
            else:
                nameNroff = name
                typeNroff = typeAndConstraintsToNroff(column)
            if not column.mutable:
                typeNroff = "immutable %s" % typeNroff
            body += '.IP "\\fB%s\\fR: %s"\n' % (nameNroff, typeNroff)
            body += block_xml_to_nroff(node.childNodes, '.IP') + "\n"
            summary += [('column', nameNroff, typeNroff)]
        elif node.tagName == 'group':
            title = node.attributes["title"].nodeValue
            subSummary, subIntro, subBody = columnGroupToNroff(
                table, node, documented_columns)
            summary += [('group', title, subSummary)]
            body += '.ST "%s:"\n' % text_to_nroff(title)
            body += subIntro + subBody
        else:
            raise error.Error("unknown element %s in <table>" % node.tagName)
    return summary, intro, body


def tableSummaryToNroff(summary, level=0):
    s = ""
    for type, name, arg in summary:
        if type == 'column':
            s += ".TQ %.2fin\n\\fB%s\\fR\n%s\n" % (3 - level * .25, name, arg)
        else:
            s += ".TQ .25in\n\\fI%s:\\fR\n.RS .25in\n" % name
            s += tableSummaryToNroff(arg, level + 1)
            s += ".RE\n"
    return s


def tableToNroff(schema, tableXml):
    tableName = tableXml.attributes['name'].nodeValue
    table = schema.tables[tableName]

    documented_columns = set()
    s = """.bp
.SH "%s TABLE"
""" % tableName
    summary, intro, body = columnGroupToNroff(table, tableXml,
                                              documented_columns)
    s += intro
    s += '.SS "Summary:\n'
    s += tableSummaryToNroff(summary)
    s += '.SS "Details:\n'
    s += body

    schema_columns = set(table.columns.keys())
    undocumented_columns = schema_columns - documented_columns
    for column in undocumented_columns:
        raise error.Error("table %s has undocumented column %s"
                          % (tableName, column))

    return s


def docsToNroff(schemaFile, xmlFile, erFile, version=None):
    schema = ovs.db.schema.DbSchema.from_json(ovs.json.from_file(schemaFile))
    doc = xml.dom.minidom.parse(xmlFile).documentElement

    if doc.hasAttribute('name'):
        manpage = doc.attributes['name'].nodeValue
    else:
        manpage = schema.name

    if version is None:
        version = "UNKNOWN"

    # Putting '\" p as the first line tells "man" that the manpage
    # needs to be preprocessed by "pic".
    s = r''''\" p
.\" -*- nroff -*-
.TH "%s" 5 " DB Schema %s" "Open vSwitch %s" "Open vSwitch Manual"
.fp 5 L CR              \\" Make fixed-width font available as \\fL.
.de TQ
.  br
.  ns
.  TP "\\$1"
..
.de ST
.  PP
.  RS -0.15in
.  I "\\$1"
.  RE
..
.SH NAME
%s \- %s database schema
.PP
''' % (manpage, schema.version, version, text_to_nroff(manpage), schema.name)

    introNodes = []
    tableNodes = []
    summary = []
    for dbNode in doc.childNodes:
        if (dbNode.nodeType == dbNode.ELEMENT_NODE
            and dbNode.tagName == "table"):
            tableNodes += [dbNode]

            name = dbNode.attributes['name'].nodeValue
            if dbNode.hasAttribute("title"):
                title = dbNode.attributes['title'].nodeValue
            else:
                title = name + " configuration."
            summary += [(name, title)]
        else:
            introNodes += [dbNode]

    documented_tables = set((name for (name, title) in summary))
    schema_tables = set(schema.tables.keys())
    undocumented_tables = schema_tables - documented_tables
    for table in undocumented_tables:
        raise error.Error("undocumented table %s" % table)

    s += block_xml_to_nroff(introNodes) + "\n"

    s += r"""
.SH "TABLE SUMMARY"
.PP
The following list summarizes the purpose of each of the tables in the
\fB%s\fR database.  Each table is described in more detail on a later
page.
.IP "Table" 1in
Purpose
""" % schema.name
    for name, title in summary:
        s += r"""
.TQ 1in
\fB%s\fR
%s
""" % (name, text_to_nroff(title))

    if erFile:
        s += r"""
.\" check if in troff mode (TTY)
.if t \{
.bp
.SH "TABLE RELATIONSHIPS"
.PP
The following diagram shows the relationship among tables in the
database.  Each node represents a table.  Tables that are part of the
``root set'' are shown with double borders.  Each edge leads from the
table that contains it and points to the table that its value
represents.  Edges are labeled with their column names, followed by a
constraint on the number of allowed values: \fB?\fR for zero or one,
\fB*\fR for zero or more, \fB+\fR for one or more.  Thick lines
represent strong references; thin lines represent weak references.
.RS -1in
"""
        erStream = open(erFile, "r")
        for line in erStream:
            s += line + '\n'
        erStream.close()
        s += ".RE\\}\n"

    for node in tableNodes:
        s += tableToNroff(schema, node) + "\n"
    return s


def usage():
    print("""\
%(argv0)s: ovsdb schema documentation generator
Prints documentation for an OVSDB schema as an nroff-formatted manpage.
usage: %(argv0)s [OPTIONS] SCHEMA XML
where SCHEMA is an OVSDB schema in JSON format
  and XML is OVSDB documentation in XML format.

The following options are also available:
  --er-diagram=DIAGRAM.PIC    include E-R diagram from DIAGRAM.PIC
  --version=VERSION           use VERSION to display on document footer
  -h, --help                  display this help message\
""" % {'argv0': argv0})
    sys.exit(0)


if __name__ == "__main__":
    try:
        try:
            options, args = getopt.gnu_getopt(sys.argv[1:], 'hV',
                                              ['er-diagram=',
                                               'version=', 'help'])
        except getopt.GetoptError as geo:
            sys.stderr.write("%s: %s\n" % (argv0, geo.msg))
            sys.exit(1)

        er_diagram = None
        version = None
        for key, value in options:
            if key == '--er-diagram':
                er_diagram = value
            elif key == '--version':
                version = value
            elif key in ['-h', '--help']:
                usage()
            else:
                sys.exit(0)

        if len(args) != 2:
            sys.stderr.write("%s: exactly 2 non-option arguments required "
                             "(use --help for help)\n" % argv0)
            sys.exit(1)

        # XXX we should warn about undocumented tables or columns
        s = docsToNroff(args[0], args[1], er_diagram, version)
        for line in s.split("\n"):
            line = line.strip()
            if len(line):
                print(line)

    except error.Error as e:
        sys.stderr.write("%s: %s\n" % (argv0, e.msg))
        sys.exit(1)

# Local variables:
# mode: python
# End:
