# Copyright (c) 2017 Linaro Limited.
#
# SPDX-License-Identifier: Apache-2.0

'''Runner for debugging with J-Link.'''

import argparse
from functools import partial
import logging
import os
from packaging.version import Version
from pathlib import Path
import shlex
import subprocess
import sys
import tempfile

from runners.core import ZephyrBinaryRunner, RunnerCaps, depr_action

try:
    import pylink
    from pylink.library import Library
    MISSING_REQUIREMENTS = False
except ImportError:
    MISSING_REQUIREMENTS = True

DEFAULT_JLINK_EXE = 'JLink.exe' if sys.platform == 'win32' else 'JLinkExe'
DEFAULT_JLINK_GDB_PORT = 2331

class ToggleAction(argparse.Action):

    def __call__(self, parser, args, ignored, option):
        setattr(args, self.dest, not option.startswith('--no-'))

class JLinkBinaryRunner(ZephyrBinaryRunner):
    '''Runner front-end for the J-Link GDB server.'''

    def __init__(self, cfg, device, dev_id=None,
                 commander=DEFAULT_JLINK_EXE,
                 dt_flash=True, erase=True, reset_after_load=False,
                 iface='swd', speed='auto',
                 gdbserver='JLinkGDBServer',
                 gdb_host='',
                 gdb_port=DEFAULT_JLINK_GDB_PORT,
                 tui=False, tool_opt=[]):
        super().__init__(cfg)
        self.hex_name = cfg.hex_file
        self.bin_name = cfg.bin_file
        self.elf_name = cfg.elf_file
        self.gdb_cmd = [cfg.gdb] if cfg.gdb else None
        self.device = device
        self.dev_id = dev_id
        self.commander = commander
        self.dt_flash = dt_flash
        self.erase = erase
        self.reset_after_load = reset_after_load
        self.gdbserver = gdbserver
        self.iface = iface
        self.speed = speed
        self.gdb_host = gdb_host
        self.gdb_port = gdb_port
        self.tui_arg = ['-tui'] if tui else []

        self.tool_opt = []
        for opts in [shlex.split(opt) for opt in tool_opt]:
            self.tool_opt += opts

    @classmethod
    def name(cls):
        return 'jlink'

    @classmethod
    def capabilities(cls):
        return RunnerCaps(commands={'flash', 'debug', 'debugserver', 'attach'},
                          dev_id=True, flash_addr=True, erase=True,
                          tool_opt=True)

    @classmethod
    def dev_id_help(cls) -> str:
        return '''Device identifier. Use it to select the J-Link Serial Number
                  of the device connected over USB.'''

    @classmethod
    def tool_opt_help(cls) -> str:
        return "Additional options for JLink Commander, e.g. '-autoconnect 1'"

    @classmethod
    def do_add_parser(cls, parser):
        # Required:
        parser.add_argument('--device', required=True, help='device name')

        # Optional:
        parser.add_argument('--id', required=False, dest='dev_id',
                            action=partial(depr_action,
                                           replacement='-i/--dev-id'),
                            help='Deprecated: use -i/--dev-id instead')
        parser.add_argument('--iface', default='swd',
                            help='interface to use, default is swd')
        parser.add_argument('--speed', default='auto',
                            help='interface speed, default is autodetect')
        parser.add_argument('--tui', default=False, action='store_true',
                            help='if given, GDB uses -tui')
        parser.add_argument('--gdbserver', default='JLinkGDBServer',
                            help='GDB server, default is JLinkGDBServer')
        parser.add_argument('--gdb-host', default='',
                            help='custom gdb host, defaults to the empty string '
                            'and runs a gdb server')
        parser.add_argument('--gdb-port', default=DEFAULT_JLINK_GDB_PORT,
                            help='pyocd gdb port, defaults to {}'.format(
                                DEFAULT_JLINK_GDB_PORT))
        parser.add_argument('--commander', default=DEFAULT_JLINK_EXE,
                            help=f'''J-Link Commander, default is
                            {DEFAULT_JLINK_EXE}''')
        parser.add_argument('--reset-after-load', '--no-reset-after-load',
                            dest='reset_after_load', nargs=0,
                            action=ToggleAction,
                            help='reset after loading? (default: no)')

        parser.set_defaults(reset_after_load=False)

    @classmethod
    def do_create(cls, cfg, args):
        return JLinkBinaryRunner(cfg, args.device,
                                 dev_id=args.dev_id,
                                 commander=args.commander,
                                 dt_flash=args.dt_flash,
                                 erase=args.erase,
                                 reset_after_load=args.reset_after_load,
                                 iface=args.iface, speed=args.speed,
                                 gdbserver=args.gdbserver,
                                 gdb_host=args.gdb_host,
                                 gdb_port=args.gdb_port,
                                 tui=args.tui, tool_opt=args.tool_opt)

    def print_gdbserver_message(self):
        if not self.thread_info_enabled:
            thread_msg = '; no thread info available'
        elif self.supports_thread_info:
            thread_msg = '; thread info enabled'
        else:
            thread_msg = '; update J-Link software for thread info'
        self.logger.info('J-Link GDB server running on port '
                         f'{self.gdb_port}{thread_msg}')

    @property
    def jlink_version(self):
        # Get the J-Link version as a (major, minor, rev) tuple of integers.
        #
        # J-Link's command line tools provide neither a standalone
        # "--version" nor help output that contains the version. Hack
        # around this deficiency by using the third-party pylink library
        # to load the shared library distributed with the tools, which
        # provides an API call for getting the version.
        if not hasattr(self, '_jlink_version'):
            # pylink >= 0.14.0 exposes JLink SDK DLL (libjlinkarm) in
            # JLINK_SDK_STARTS_WITH, while previous versions use JLINK_SDK_NAME
            if Version(pylink.__version__) >= Version('0.14.0'):
                sdk = Library.JLINK_SDK_STARTS_WITH
            else:
                sdk = Library.JLINK_SDK_NAME

            plat = sys.platform
            if plat.startswith('win32'):
                libname = Library.get_appropriate_windows_sdk_name() + '.dll'
            elif plat.startswith('linux'):
                libname = sdk + '.so'
            elif plat.startswith('darwin'):
                libname = sdk + '.dylib'
            else:
                self.logger.warning(f'unknown platform {plat}; assuming UNIX')
                libname = sdk + '.so'

            lib = Library(dllpath=os.fspath(Path(self.commander).parent /
                                            libname))
            version = int(lib.dll().JLINKARM_GetDLLVersion())
            self.logger.debug('JLINKARM_GetDLLVersion()=%s', version)
            # The return value is an int with 2 decimal digits per
            # version subfield.
            self._jlink_version = (version // 10000,
                                   (version // 100) % 100,
                                   version % 100)

        return self._jlink_version

    @property
    def jlink_version_str(self):
        # Converts the numeric revision tuple to something human-readable.
        if not hasattr(self, '_jlink_version_str'):
            major, minor, rev = self.jlink_version
            rev_str = chr(ord('a') + rev - 1) if rev else ''
            self._jlink_version_str = f'{major}.{minor:02}{rev_str}'
        return self._jlink_version_str

    @property
    def supports_nogui(self):
        # -nogui was introduced in J-Link Commander v6.80
        return self.jlink_version >= (6, 80, 0)

    @property
    def supports_thread_info(self):
        # RTOSPlugin_Zephyr was introduced in 7.11b
        return self.jlink_version >= (7, 11, 2)

    def do_run(self, command, **kwargs):
        if MISSING_REQUIREMENTS:
            raise RuntimeError('one or more Python dependencies were missing; '
                               "see the getting started guide for details on "
                               "how to fix")
        # Convert commander to a real absolute path. We need this to
        # be able to find the shared library that tells us what
        # version of the tools we're using.
        self.commander = os.fspath(
            Path(self.require(self.commander)).resolve())
        self.logger.info(f'JLink version: {self.jlink_version_str}')

        rtos = self.thread_info_enabled and self.supports_thread_info
        plugin_dir = os.fspath(Path(self.commander).parent / 'GDBServer' /
                               'RTOSPlugin_Zephyr')

        server_cmd = ([self.gdbserver] +
                       # only USB connections supported
                      ['-select', 'usb' + (f'={self.dev_id}'
                                           if self.dev_id else ''),
                       '-port', str(self.gdb_port),
                       '-if', self.iface,
                       '-speed', self.speed,
                       '-device', self.device,
                       '-silent',
                       '-singlerun'] +
                      (['-nogui'] if self.supports_nogui else []) +
                      (['-rtos', plugin_dir] if rtos else []) +
                      self.tool_opt)

        if command == 'flash':
            self.flash(**kwargs)
        elif command == 'debugserver':
            if self.gdb_host:
                raise ValueError('Cannot run debugserver with --gdb-host')
            self.require(self.gdbserver)
            self.print_gdbserver_message()
            self.check_call(server_cmd)
        else:
            if self.gdb_cmd is None:
                raise ValueError('Cannot debug; gdb is missing')
            if self.elf_name is None:
                raise ValueError('Cannot debug; elf is missing')
            client_cmd = (self.gdb_cmd +
                          self.tui_arg +
                          [self.elf_name] +
                          ['-ex', 'target remote {}:{}'.format(self.gdb_host, self.gdb_port)])
            if command == 'debug':
                client_cmd += ['-ex', 'monitor halt',
                               '-ex', 'monitor reset',
                               '-ex', 'load']
                if self.reset_after_load:
                    client_cmd += ['-ex', 'monitor reset']
            if not self.gdb_host:
                self.require(self.gdbserver)
                self.print_gdbserver_message()
                self.run_server_and_client(server_cmd, client_cmd)
            else:
                self.run_client(client_cmd)

    def flash(self, **kwargs):
        lines = [
            'ExitOnError 1',  # Treat any command-error as fatal
            'r',  # Reset and halt the target
        ]

        if self.erase:
            lines.append('erase') # Erase all flash sectors

        # Get the build artifact to flash, preferring .hex over .bin
        if self.hex_name is not None and os.path.isfile(self.hex_name):
            flash_file = self.hex_name
            flash_cmd = f'loadfile "{self.hex_name}"'
        elif self.bin_name is not None and os.path.isfile(self.bin_name):
            if self.dt_flash:
                flash_addr = self.flash_address_from_build_conf(self.build_conf)
            else:
                flash_addr = 0
            flash_file = self.bin_name
            flash_cmd = f'loadfile "{self.bin_name}" 0x{flash_addr:x}'
        else:
            err = 'Cannot flash; no hex ({}) or bin ({}) files found.'
            raise ValueError(err.format(self.hex_name, self.bin_name))

        # Flash the selected build artifact
        lines.append(flash_cmd)

        if self.reset_after_load:
            lines.append('r') # Reset and halt the target

        lines.append('g') # Start the CPU

        # Reset the Debug Port CTRL/STAT register
        # Under normal operation this is done automatically, but if other
        # JLink tools are running, it is not performed.
        # The J-Link scripting layer chains commands, meaning that writes are
        # not actually performed until after the next operation. After writing
        # the register, read it back to perform this flushing.
        lines.append('writeDP 1 0')
        lines.append('readDP 1')

        lines.append('q') # Close the connection and quit

        self.logger.debug('JLink commander script:\n' +
                          '\n'.join(lines))

        # Don't use NamedTemporaryFile: the resulting file can't be
        # opened again on Windows.
        with tempfile.TemporaryDirectory(suffix='jlink') as d:
            fname = os.path.join(d, 'runner.jlink')
            with open(fname, 'wb') as f:
                f.writelines(bytes(line + '\n', 'utf-8') for line in lines)
            cmd = ([self.commander] +
                    # only USB connections supported
                   (['-USB', f'{self.dev_id}'] if self.dev_id else []) +
                   (['-nogui', '1'] if self.supports_nogui else []) +
                   ['-if', self.iface,
                    '-speed', self.speed,
                    '-device', self.device,
                    '-CommanderScript', fname] +
                   (['-nogui', '1'] if self.supports_nogui else []) +
                   self.tool_opt)

            self.logger.info('Flashing file: {}'.format(flash_file))
            kwargs = {}
            if not self.logger.isEnabledFor(logging.DEBUG):
                kwargs['stdout'] = subprocess.DEVNULL
            self.check_call(cmd, **kwargs)