#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2019, Google Inc.
#
# Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
#
# gen-controls.py - Generate control definitions from YAML

import argparse
from functools import reduce
import operator
import string
import sys
import yaml
import os


class ControlEnum(object):
    def __init__(self, data):
        self.__data = data

    @property
    def description(self):
        """The enum description"""
        return self.__data.get('description')

    @property
    def name(self):
        """The enum name"""
        return self.__data.get('name')

    @property
    def value(self):
        """The enum value"""
        return self.__data.get('value')


class Control(object):
    def __init__(self, name, data, vendor):
        self.__name = name
        self.__data = data
        self.__enum_values = None
        self.__size = None
        self.__vendor = vendor

        enum_values = data.get('enum')
        if enum_values is not None:
            self.__enum_values = [ControlEnum(enum) for enum in enum_values]

        size = self.__data.get('size')
        if size is not None:
            if len(size) == 0:
                raise RuntimeError(f'Control `{self.__name}` size must have at least one dimension')

            # Compute the total number of elements in the array. If any of the
            # array dimension is a string, the array is variable-sized.
            num_elems = 1
            for dim in size:
                if type(dim) is str:
                    num_elems = 0
                    break

                dim = int(dim)
                if dim <= 0:
                    raise RuntimeError(f'Control `{self.__name}` size must have positive values only')

                num_elems *= dim

            self.__size = num_elems

    @property
    def description(self):
        """The control description"""
        return self.__data.get('description')

    @property
    def enum_values(self):
        """The enum values, if the control is an enumeration"""
        if self.__enum_values is None:
            return
        for enum in self.__enum_values:
            yield enum

    @property
    def is_enum(self):
        """Is the control an enumeration"""
        return self.__enum_values is not None

    @property
    def vendor(self):
        """The vendor string, or None"""
        return self.__vendor

    @property
    def name(self):
        """The control name (CamelCase)"""
        return self.__name

    @property
    def type(self):
        typ = self.__data.get('type')
        size = self.__data.get('size')

        if typ == 'string':
            return 'std::string'

        if self.__size is None:
            return typ

        if self.__size:
            return f"Span<const {typ}, {self.__size}>"
        else:
            return f"Span<const {typ}>"


def snake_case(s):
    return ''.join([c.isupper() and ('_' + c) or c for c in s]).strip('_')


def format_description(description):
    description = description.strip('\n').split('\n')
    description[0] = '\\brief ' + description[0]
    return '\n'.join([(line and ' * ' or ' *') + line for line in description])


def generate_cpp(controls):
    enum_doc_start_template = string.Template('''/**
 * \\enum ${name}Enum
 * \\brief Supported ${name} values''')
    enum_doc_value_template = string.Template(''' * \\var ${value}
${description}''')
    doc_template = string.Template('''/**
 * \\var ${name}
${description}
 */''')
    def_template = string.Template('extern const Control<${type}> ${name}(${id_name}, "${name}");')
    enum_values_doc = string.Template('''/**
 * \\var ${name}Values
 * \\brief List of all $name supported values
 */''')
    enum_values_start = string.Template('''extern const std::array<const ControlValue, ${size}> ${name}Values = {''')
    enum_values_values = string.Template('''\tstatic_cast<int32_t>(${name}),''')

    ctrls_doc = {}
    ctrls_def = {}
    ctrls_map = []

    for ctrl in controls:
        id_name = snake_case(ctrl.name).upper()

        vendor = ctrl.vendor
        if vendor not in ctrls_doc:
            ctrls_doc[vendor] = []
            ctrls_def[vendor] = []

        info = {
            'name': ctrl.name,
            'type': ctrl.type,
            'description': format_description(ctrl.description),
            'id_name': id_name,
        }

        target_doc = ctrls_doc[vendor]
        target_def = ctrls_def[vendor]

        if ctrl.is_enum:
            enum_doc = []
            enum_doc.append(enum_doc_start_template.substitute(info))

            num_entries = 0
            for enum in ctrl.enum_values:
                value_info = {
                    'name': ctrl.name,
                    'value': enum.name,
                    'description': format_description(enum.description),
                }
                enum_doc.append(enum_doc_value_template.substitute(value_info))
                num_entries += 1

            enum_doc = '\n *\n'.join(enum_doc)
            enum_doc += '\n */'
            target_doc.append(enum_doc)

            values_info = {
                'name': info['name'],
                'size': num_entries,
            }
            target_doc.append(enum_values_doc.substitute(values_info))
            target_def.append(enum_values_start.substitute(values_info))
            for enum in ctrl.enum_values:
                value_info = {
                    'name': enum.name
                }
                target_def.append(enum_values_values.substitute(value_info))
            target_def.append("};")

        target_doc.append(doc_template.substitute(info))
        target_def.append(def_template.substitute(info))

        vendor_ns = vendor + '::' if vendor != "libcamera" else ''
        ctrls_map.append('\t{ ' + vendor_ns + id_name + ', &' + vendor_ns + ctrl.name + ' },')

    vendor_ctrl_doc_sub = []
    vendor_ctrl_template = string.Template('''
/**
 * \\brief Namespace for ${vendor} controls
 */
namespace ${vendor} {

${vendor_controls_str}

} /* namespace ${vendor} */''')

    for vendor in [v for v in ctrls_doc.keys() if v not in ['libcamera']]:
        vendor_ctrl_doc_sub.append(vendor_ctrl_template.substitute({'vendor': vendor, 'vendor_controls_str': '\n\n'.join(ctrls_doc[vendor])}))

    vendor_ctrl_def_sub = []
    for vendor in [v for v in ctrls_def.keys() if v not in ['libcamera']]:
        vendor_ctrl_def_sub.append(vendor_ctrl_template.substitute({'vendor': vendor, 'vendor_controls_str': '\n'.join(ctrls_def[vendor])}))

    return {
        'controls_doc': '\n\n'.join(ctrls_doc['libcamera']),
        'controls_def': '\n'.join(ctrls_def['libcamera']),
        'controls_map': '\n'.join(ctrls_map),
        'vendor_controls_doc': '\n'.join(vendor_ctrl_doc_sub),
        'vendor_controls_def': '\n'.join(vendor_ctrl_def_sub),
    }


def generate_h(controls, mode, ranges):
    enum_template_start = string.Template('''enum ${name}Enum {''')
    enum_value_template = string.Template('''\t${name} = ${value},''')
    enum_values_template = string.Template('''extern const std::array<const ControlValue, ${size}> ${name}Values;''')
    template = string.Template('''extern const Control<${type}> ${name};''')

    ctrls = {}
    ids = {}
    id_value = {}

    for ctrl in controls:
        id_name = snake_case(ctrl.name).upper()

        vendor = ctrl.vendor
        if vendor not in ctrls:
            if vendor not in ranges.keys():
                raise RuntimeError(f'Control id range is not defined for vendor {vendor}')
            id_value[vendor] = ranges[vendor] + 1
            ids[vendor] = []
            ctrls[vendor] = []

        target_ids = ids[vendor]
        target_ids.append('\t' + id_name + ' = ' + str(id_value[vendor]) + ',')

        info = {
            'name': ctrl.name,
            'type': ctrl.type,
        }

        target_ctrls = ctrls[vendor]

        if ctrl.is_enum:
            target_ctrls.append(enum_template_start.substitute(info))

            num_entries = 0
            for enum in ctrl.enum_values:
                value_info = {
                    'name': enum.name,
                    'value': enum.value,
                }
                target_ctrls.append(enum_value_template.substitute(value_info))
                num_entries += 1
            target_ctrls.append("};")

            values_info = {
                'name': info['name'],
                'size': num_entries,
            }
            target_ctrls.append(enum_values_template.substitute(values_info))

        target_ctrls.append(template.substitute(info))
        id_value[vendor] += 1

    vendor_template = string.Template('''
namespace ${vendor} {

#define LIBCAMERA_HAS_${vendor_def}_VENDOR_${mode}

enum {
${vendor_enums}
};

${vendor_controls}

} /* namespace ${vendor} */
''')

    vendor_sub = []
    for vendor in [v for v in ctrls.keys() if v != 'libcamera']:
        vendor_sub.append(vendor_template.substitute({'mode': mode.upper(),
                                                      'vendor': vendor,
                                                      'vendor_def': vendor.upper(),
                                                      'vendor_enums': '\n'.join(ids[vendor]),
                                                      'vendor_controls': '\n'.join(ctrls[vendor])}))

    return {
        'ids': '\n'.join(ids['libcamera']),
        'controls': '\n'.join(ctrls['libcamera']),
        'vendor_controls': '\n'.join(vendor_sub)
    }


def fill_template(template, data):

    template = open(template, 'rb').read()
    template = template.decode('utf-8')
    template = string.Template(template)
    return template.substitute(data)


def main(argv):

    # Parse command line arguments
    parser = argparse.ArgumentParser()
    parser.add_argument('--mode', '-m', type=str, required=True, choices=['controls', 'properties'],
                        help='Mode of operation')
    parser.add_argument('--output', '-o', metavar='file', type=str,
                        help='Output file name. Defaults to standard output if not specified.')
    parser.add_argument('--ranges', '-r', type=str, required=True,
                        help='Control id range reservation file.')
    parser.add_argument('--template', '-t', dest='template', type=str, required=True,
                        help='Template file name.')
    parser.add_argument('input', type=str, nargs='+',
                        help='Input file name.')

    args = parser.parse_args(argv[1:])

    ranges = {}
    with open(args.ranges, 'rb') as f:
        data = open(args.ranges, 'rb').read()
        ranges = yaml.safe_load(data)['ranges']

    controls = []
    for input in args.input:
        with open(input, 'rb') as f:
            data = f.read()
            vendor = yaml.safe_load(data)['vendor']
            ctrls = yaml.safe_load(data)['controls']
            controls = controls + [Control(*ctrl.popitem(), vendor) for ctrl in ctrls]

    if args.template.endswith('.cpp.in'):
        data = generate_cpp(controls)
    elif args.template.endswith('.h.in'):
        data = generate_h(controls, args.mode, ranges)
    else:
        raise RuntimeError('Unknown template type')

    data = fill_template(args.template, data)

    if args.output:
        output = open(args.output, 'wb')
        output.write(data.encode('utf-8'))
        output.close()
    else:
        sys.stdout.write(data)

    return 0


if __name__ == '__main__':
    sys.exit(main(sys.argv))