#!/bin/env python
# -*- coding: utf-8 -*-
# Program to find devices to support in LineageOS
# Copyright (C) 2019 Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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, see <https://www.gnu.org/licenses/>.

import os
import re
import sys
import yaml

basedir = '_data' + os.sep + 'devices'
results = {}
last_lineageos_version = 17.1

def still_supported(document):
    if not last_lineageos_version in document['versions']:
        return False
    if 'channels' in document.keys() and 'discontinued' in document['channels']:
       return False
    if 'maintainers' in document.keys() and len(document['maintainers']) == 0:
        return False

    return True

# In some cases it might be interesting to look if a given device has a modem in
# the case where the SOC is known not to have any modem, so we can automatically
# know that the is no shared memory between the modem and the device if there is
# no modem.
# Another case would be for SOCs that have optional modems where the device has
# no modem feature and that we are sure that the modem CPU is not running any code.
def device_has_modem(vendor, product):
    if vendor == 'Google' and product == 'Pixel C':
        return False

    # unknown
    return None

def device_has_shared_memory_between_modem_and_soc(vendor, product):
    if vendor == 'Samsung' and product == 'Galaxy S5 Neo':
        # In the "Samsung Mobile Modem Driver (SVNET2) V1 for
        # Memory-type Interface" section in lineageos_s5neolte_defconfig
        # in the lineage-17.0 branch of
        # https://github.com/LineageOS/android_kernel_samsung_universal7580
        # there is the following configuration:
        # CONFIG_LINK_DEVICE_SHMEM=y
        # CONFIG_LINK_DEVICE_HSIC is not set
        return True
    if vendor == 'Samsung' and product == 'Galaxy J7 (2015)':
        # lineageos_j7elte_defconfig in the lineage-17.1 branch of
        # android_kernel_samsung_universal7580 has the following:
        # CONFIG_LINK_DEVICE_SHMEM=y. All other CONFIG_LINK_DEVICE_
        # are 'is not set'.
        return True

    # unknown
    return None

def soc_has_modem(vendor, product):
    if vendor == 'HiSilicon':
        pass
    elif vendor == 'Intel':
        pass
    elif vendor in ['Nvidia', 'NVIDIA'] and re.search("^Tegra 4", product):
        # The modem could be implemented in software
        pass
    elif vendor in ['Nvidia', 'NVIDIA'] and re.search("^Tegra K1", product):
        pass
    elif vendor in ['Nvidia', 'NVIDIA'] and re.search("^Tegra X1", product):
        pass
    elif vendor == 'Qualcomm' and re.search("^MSM", product):
        return True
    elif vendor == 'Qualcomm' and re.search("^APQ", product) or re.search("^Snapdragon 600", product):
        return False
    elif vendor == 'Qualcomm' and product == "Qualcomm SDM845 Snapdragon 845":
        return True
    elif vendor == 'Qualcomm' and re.search("^SDM", product):
        pass
    elif vendor == 'Qualcomm' and (re.search("^SM", product) or re.search("^sm", product)):
        pass
    elif vendor == 'Qualcomm' and re.search("^Snapdragon", product):
        pass
    elif vendor == 'Samsung' and re.search("^Exynos", product):
        # Some exynos modems do exists but they are either standalone
        # modems or are SOCs where the AP is a Cortex M7 which are very
        # unlikely to be able to run Android for smartphones or tablets
        return False
    elif vendor == 'TI' and product in ['OMAP4430', 'OMAP4460']:
        # The modem could be implemented in software in the DSP but I never saw
        # it on any device. It's used like that on the SysmoBTS which are BTS,
        # not phones or a tablets.
        return False
    else:
        print("<{}|{}>".format(vendor, product))
        sys.exit(1)
    # Unknown
    return None

def parse_soc(soc):
    soc_vendors = [
        "HiSilicon",
        "Intel",
        "NVIDIA",
        "Nvidia",
        "Qualcomm",
        "Samsung",
        "TI"]

    soc_vendors_quirks = {
        # ^Match : Vendor
        'Exynos' : 'Samsung',
    }

    results = {}
    found = False
    for vendor in soc_vendors:
        match = re.search("^{0} (.*)".format(vendor), soc)
        if match:
            found = True
            if vendor == 'NVIDIA':
                vendor = 'Nvidia'
            results['vendor'] = vendor
            results['product'] = match.group(1)
            results['has_modem'] = soc_has_modem(results['vendor'], results['product'])

    if not found:
        for match_data, vendor in soc_vendors_quirks.items():
            match = re.search("^{0} (.*)".format(match_data), soc)
            if match:
                found = True
                results['vendor'] = vendor
                results['product'] = soc
                results['has_modem'] = soc_has_modem(results['vendor'], results['product'])

    if not 'vendor' in results:
        print("TODO: Handle vendor in \"{}\"".format(soc))
        sys.exit(1)

    return results

def battery_is_removable(battery):
    # Example: Set top box
    if battery == "None" or battery == None:
        return None

    if 'removable' not in battery:
        print("TODO: Handle batteries where removable is absent: {}".format(battery))
        sys.exit(1)

    removable_battery = battery.get('removable')
    if removable_battery == True:
        return True
    elif removable_battery == False:
        return False
    else:
        print("TODO: Handle batteries where removable is \"{}\": {}".format(removable, battery))
        sys.exit(1)

def has_removable_battery(document):
    removable_battery = None
    if 'battery' not in document:
        # We don't know the policies reguarding incomplete data so the data
        # may either be incomplete or the device may not have a battery.
        print("TODO: Add support for devices lacking a battery")
        sys.exit(1)
    else:
        battery = document.get('battery')
        if type(battery) is not list:
            return battery_is_removable(battery)
        else:
            for battery_version in battery:
                if battery_version == None:
                    continue

                if len(battery_version.keys()) != 1:
                    print("TODO: Add support for battery versions with multiple keys: {}".format(battery_version))
                    sys.exit(1)

                nr_removable = 0
                nr_not_removable = 0

                (battery_name, battery_data), = battery_version.items()

                removable = battery_is_removable(battery_data)
                if removable == True:
                    nr_removable += 1
                elif removable == False:
                    nr_not_removable += 1

            if nr_removable == 0 and nr_not_removable > 0:
                return False
            elif nr_not_removable == 0 and nr_removable > 0:
                return True
            else:
                print("TODO: The data has removable and non-removable batteries"
                      "versions for the same device: {}".format(battery))
                print("      Add support for it in the parsing code")
                sys.exit(1)

def interesting_for_replicant(document):
    # For smartphones or tablets with a modem, since the modem is in
    # the same SOC, we would need to do some extensive review of the SOC
    # architecture to understand if the modem can be isolated with an IOMMU
    # We would also need to make sure that the IOMMU is correctly setup (hard)
    # and that the setup happens before the modem core are booted.
    # For devices without a modem, we would still need to make sure that the
    # sound card and the microphone is completely under the control of free
    # software and that there aren't too much proprietary libraries to replace
    soc = parse_soc(document['soc'])
    if soc_has_modem(soc['vendor'], soc['product']) == True:
        return False

    if device_has_shared_memory_between_modem_and_soc(document['vendor'],
                                                      document['name']):
        return False

    # Non replaceable batteries causes too much issues for both users
    # and developers as once you buy a device second hand, the battery
    # doesn't last as much as when the device is new. On some devices,
    # replicing non-removable batteries can be very difficult and damage
    # the device along the way
    #
    # There are some devices where the battery is not removable but
    # since the device can be easily opened, and that the battery has
    # a connector, it might be possible for an experienced user or
    # developer, or a repair shop, or a repair café to open the device
    # and replace the battery.
    #
    # However it would take more research to understand if compatible
    # batteries replacement can easily be found. The LineageOS wiki also
    # doesn't have a way to distinguish between devices that can be easily
    # opened and the ones that aren't.
    #
    # So for now we aproximate non-removable batteries to non-replaceable
    # batteries until we find a way to deal with it.
    if document['type'] != 'Set top box' and not has_removable_battery(document):
        return False

    return True

def store_infos(results, document):
    fields = ['vendor', 'name', 'type']

    device_dict = {}
    for field in fields:
        device_dict[field] = document[field]

    device_dict['removable_battery'] = has_removable_battery(document)

    soc = document['soc']
    soc_data = parse_soc(soc)
    soc_vendor = None
    soc_product = None

    if soc_data['vendor'] not in results:
        results[soc_data['vendor']] = {}
    soc_vendor = results[soc_data['vendor']]

    if soc_data['product'] not in soc_vendor:
        soc_vendor[soc_data['product']] = []
    soc_product = soc_vendor[soc_data['product']]

    soc_product.append(device_dict)

def print_results(results):
    soc_vendors = list(results.keys())
    soc_vendors.sort()
    for soc_vendor in soc_vendors:
        print ("{0}:".format(soc_vendor))
        for soc_product in results[soc_vendor]:
            print ("- {0}:".format(soc_product))
            for device in results[soc_vendor][soc_product]:
                print("  * {0}: {1} ({2})".format(
                    device['vendor'], device['name'], device['type']))

def find_devices(path):
    for filename in os.listdir(path + os.sep + basedir):
        filepath = path + os.sep + basedir + os.sep + filename
        if re.search("\.yml$", filepath):
            yaml_file = open(filepath, 'r')
            document = yaml.safe_load(yaml_file)
            if still_supported(document) and interesting_for_replicant(document):
                store_infos(results, document)
    print_results(results)

def usage(argv0):
    progname = os.path.basename(argv0)
    print("{} [path/to/lineage_wiki]".format(progname))
    sys.exit(1)

if len(sys.argv) != 2:
    usage(sys.argv[0])

find_devices(sys.argv[1])