import json
import os
import re
import shlex
import subprocess
import sys
import threading
import time
from threading import Thread

from idf_py_actions.errors import FatalError
from idf_py_actions.tools import ensure_build_directory

PYTHON = sys.executable


def action_extensions(base_actions, project_path):
    OPENOCD_OUT_FILE = 'openocd_out.txt'
    GDBGUI_OUT_FILE = 'gdbgui_out.txt'
    # Internal dictionary of currently active processes, threads and their output files
    processes = {'threads_to_join': [], 'openocd_issues': None}

    def _check_for_common_openocd_issues(file_name, print_all=True):
        if processes['openocd_issues'] is not None:
            return processes['openocd_issues']
        try:
            message = 'Please check JTAG connection!'
            with open(file_name, 'r') as f:
                content = f.read()
                if print_all:
                    print(content)
                if re.search(r'Address already in use', content):
                    message = ('Please check if another process uses the mentioned ports. OpenOCD already running, perhaps in the background?\n'
                               'Please list all processes to check if OpenOCD is already running; if so, terminate it before starting OpenOCD from idf.py')
        finally:
            processes['openocd_issues'] = message
            return message

    def _check_openocd_errors(fail_if_openocd_failed, target, ctx):
        if fail_if_openocd_failed:
            if 'openocd' in processes and processes['openocd'] is not None:
                p = processes['openocd']
                name = processes['openocd_outfile_name']
                # watch OpenOCD (for 5x500ms) to check if it hasn't terminated or outputs an error
                for _ in range(5):
                    if p.poll() is not None:
                        print('OpenOCD exited with {}'.format(p.poll()))
                        break
                    with open(name, 'r') as f:
                        content = f.read()
                        if re.search(r'no device found', content):
                            break
                        if re.search(r'Listening on port \d+ for gdb connections', content):
                            # expect OpenOCD has started successfully - stop watching
                            return
                    time.sleep(0.5)
                else:
                    return
                # OpenOCD exited or error message detected -> print possible output and terminate
                raise FatalError('Action "{}" failed due to errors in OpenOCD:\n{}'.format(target, _check_for_common_openocd_issues(name)), ctx)

    def _terminate_async_target(target):
        if target in processes and processes[target] is not None:
            try:
                if target + '_outfile' in processes:
                    processes[target + '_outfile'].close()
                p = processes[target]
                if p.poll() is None:
                    p.terminate()
                    # waiting 10x100ms for the process to terminate gracefully
                    for _ in range(10):
                        if p.poll() is not None:
                            break
                        time.sleep(0.1)
                    else:
                        p.kill()
                if target + '_outfile_name' in processes:
                    if target == 'openocd':
                        print(_check_for_common_openocd_issues(processes[target + '_outfile_name'], print_all=False))
                    os.unlink(processes[target + '_outfile_name'])
            except Exception as e:
                print(e)
                print('Failed to close/kill {}'.format(target))
            processes[target] = None  # to indicate this has ended

    def _get_commandline_options(ctx):
        """ Return all the command line options up to first action """
        # This approach ignores argument parsing done Click
        result = []

        for arg in sys.argv:
            if arg in ctx.command.commands_with_aliases:
                break

            result.append(arg)

        return result

    def create_local_gdbinit(gdbinit, elf_file):
        with open(gdbinit, 'w') as f:
            if os.name == 'nt':
                elf_file = elf_file.replace('\\','\\\\')
            f.write('file {}\n'.format(elf_file))
            f.write('target remote :3333\n')
            f.write('mon reset halt\n')
            f.write('flushregs\n')
            f.write('thb app_main\n')
            f.write('c\n')

    def debug_cleanup():
        print('cleaning up debug targets')
        for t in processes['threads_to_join']:
            if threading.currentThread() != t:
                t.join()
        _terminate_async_target('openocd')
        _terminate_async_target('gdbgui')
        _terminate_async_target('gdb')

    def post_debug(action, ctx, args, **kwargs):
        """ Deal with asynchronous targets, such as openocd running in background """
        if kwargs['block'] == 1:
            for target in ['openocd', 'gdbgui']:
                if target in processes and processes[target] is not None:
                    break
            else:
                return
            try:
                p = processes[target]
                name = processes[target + '_outfile_name']
                pos = 0
                while True:
                    with open(name, 'r') as f:
                        f.seek(pos)
                        for line in f:
                            print(line.rstrip())
                        pos = f.tell()
                    if p.poll() is not None:
                        print('"{}" exited with {}'.format(target, p.poll()))
                        break
                    time.sleep(0.5)
            except KeyboardInterrupt:
                print('Terminated -> exiting debug utility targets')
        _terminate_async_target('openocd')
        _terminate_async_target('gdbgui')

    def get_project_desc(args, ctx):
        desc_path = os.path.join(args.build_dir, 'project_description.json')
        if not os.path.exists(desc_path):
            ensure_build_directory(args, ctx.info_name)
        with open(desc_path, 'r') as f:
            project_desc = json.load(f)
            return project_desc

    def openocd(action, ctx, args, openocd_scripts, openocd_commands):
        """
        Execute openocd as external tool
        """
        OPENOCD_TAGET_CONFIG = {
            'esp32': '-f board/esp32-wrover-kit-3.3v.cfg',
            'esp32s2': '-f board/esp32s2-kaluga-1.cfg',
        }
        if os.getenv('OPENOCD_SCRIPTS') is None:
            raise FatalError('OPENOCD_SCRIPTS not found in the environment: Please run export.sh/export.bat', ctx)
        openocd_arguments = os.getenv('OPENOCD_COMMANDS') if openocd_commands is None else openocd_commands
        project_desc = get_project_desc(args, ctx)
        if openocd_arguments is None:
            # use default value if commands not defined in the environment nor command line
            target = project_desc['target']
            default_args = '-f interface/ftdi/esp32_devkitj_v1.cfg -f target/{}.cfg'.format(target)
            openocd_arguments = OPENOCD_TAGET_CONFIG.get(target, default_args)
            print('Note: OpenOCD cfg not found (via env variable OPENOCD_COMMANDS nor as a --openocd-commands argument)\n'
                  'OpenOCD arguments default to: "{}"'.format(openocd_arguments))
        # script directory is taken from the environment by OpenOCD, update only if command line arguments to override
        if openocd_scripts is not None:
            openocd_arguments += ' -s {}'.format(openocd_scripts)
        local_dir = project_desc['build_dir']
        args = ['openocd'] + shlex.split(openocd_arguments)
        openocd_out_name = os.path.join(local_dir, OPENOCD_OUT_FILE)
        openocd_out = open(openocd_out_name, 'a+')
        try:
            process = subprocess.Popen(args, stdout=openocd_out, stderr=subprocess.STDOUT, bufsize=1)
        except Exception as e:
            print(e)
            raise FatalError('Error starting openocd. Please make sure it is installed and is present in executable paths', ctx)

        processes['openocd'] = process
        processes['openocd_outfile'] = openocd_out
        processes['openocd_outfile_name'] = openocd_out_name
        print('OpenOCD started as a background task {}'.format(process.pid))

    def gdbui(action, ctx, args, gdbgui_port, gdbinit, require_openocd):
        """
        Asynchronous GDB-UI target
        """
        project_desc = get_project_desc(args, ctx)
        local_dir = project_desc['build_dir']
        gdb = project_desc['monitor_toolprefix'] + 'gdb'
        if gdbinit is None:
            gdbinit = os.path.join(local_dir, 'gdbinit')
            create_local_gdbinit(gdbinit, os.path.join(args.build_dir, project_desc['app_elf']))
        args = ['gdbgui', '-g', gdb, '--gdb-args="-x={}"'.format(gdbinit)]
        if gdbgui_port is not None:
            args += ['--port', gdbgui_port]
        gdbgui_out_name = os.path.join(local_dir, GDBGUI_OUT_FILE)
        gdbgui_out = open(gdbgui_out_name, 'a+')
        env = os.environ.copy()
        # The only known solution for https://github.com/cs01/gdbgui/issues/359 is to set the following environment
        # variable. The greenlet package cannot be downgraded for compatibility with other requirements (gdbgui,
        # pygdbmi).
        env['PURE_PYTHON'] = '1'
        try:
            process = subprocess.Popen(args, stdout=gdbgui_out, stderr=subprocess.STDOUT, bufsize=1, env=env)
        except Exception as e:
            print(e)
            raise FatalError('Error starting gdbgui. Please make sure gdbgui can be started', ctx)

        processes['gdbgui'] = process
        processes['gdbgui_outfile'] = gdbgui_out
        processes['gdbgui_outfile_name'] = gdbgui_out_name
        print('gdbgui started as a background task {}'.format(process.pid))
        _check_openocd_errors(fail_if_openocd_failed, action, ctx)

    def global_callback(ctx, global_args, tasks):
        def move_to_front(task_name):
            for index, task in enumerate(tasks):
                if task.name == task_name:
                    tasks.insert(0, tasks.pop(index))
                    break

        debug_targets = any([task.name in ('openocd', 'gdbgui') for task in tasks])
        if debug_targets:
            # Register the meta cleanup callback -> called on FatalError
            ctx.meta['cleanup'] = debug_cleanup
            move_to_front('gdbgui')     # possibly 2nd
            move_to_front('openocd')    # always 1st
            # followed by "monitor", "gdb" or "gdbtui" in any order

            post_action = ctx.invoke(ctx.command.get_command(ctx, 'post_debug'))
            if any([task.name in ('monitor', 'gdb', 'gdbtui') for task in tasks]):
                post_action.action_args['block'] = 0
            else:
                post_action.action_args['block'] = 1
            tasks.append(post_action)   # always last
        if any([task.name == 'openocd' for task in tasks]):
            for task in tasks:
                if task.name in ('gdb', 'gdbgui', 'gdbtui'):
                    task.action_args['require_openocd'] = True

    def run_gdb(gdb_args):
        p = subprocess.Popen(gdb_args)
        processes['gdb'] = p
        return p.wait()

    def gdbtui(action, ctx, args, gdbinit, require_openocd):
        """
        Synchronous GDB target with text ui mode
        """
        gdb(action, ctx, args, 1, gdbinit, require_openocd)

    def gdb(action, ctx, args, gdb_tui, gdbinit, require_openocd):
        """
        Synchronous GDB target
        """
        watch_openocd = Thread(target=_check_openocd_errors, args=(fail_if_openocd_failed, action, ctx, ))
        watch_openocd.start()
        processes['threads_to_join'].append(watch_openocd)
        desc_path = os.path.join(args.build_dir, 'project_description.json')
        if not os.path.exists(desc_path):
            ensure_build_directory(args, ctx.info_name)
        with open(desc_path, 'r') as f:
            project_desc = json.load(f)

        elf_file = os.path.join(args.build_dir, project_desc['app_elf'])
        if not os.path.exists(elf_file):
            raise FatalError('ELF file not found. You need to build & flash the project before running debug targets', ctx)
        gdb = project_desc['monitor_toolprefix'] + 'gdb'
        local_dir = project_desc['build_dir']
        if gdbinit is None:
            gdbinit = os.path.join(local_dir, 'gdbinit')
            create_local_gdbinit(gdbinit, elf_file)
        args = [gdb, '-x={}'.format(gdbinit)]
        if gdb_tui is not None:
            args += ['-tui']
        t = Thread(target=run_gdb, args=(args, ))
        t.start()
        while True:
            try:
                t.join()
                break
            except KeyboardInterrupt:
                # Catching Keyboard interrupt, as this is used for breaking running program in gdb
                continue
            finally:
                watch_openocd.join()
                try:
                    processes['threads_to_join'].remove(watch_openocd)
                except ValueError:
                    # Valid scenario: watch_openocd task won't be in the list if openocd not started from idf.py
                    pass

    fail_if_openocd_failed = {
        'names': ['--require-openocd', '--require_openocd'],
        'help':
        ('Fail this target if openocd (this targets dependency) failed.\n'),
        'is_flag': True,
        'default': False,
    }
    gdbinit = {
        'names': ['--gdbinit'],
        'help': ('Specify the name of gdbinit file to use\n'),
        'default': None,
    }
    debug_actions = {
        'global_action_callbacks': [global_callback],
        'actions': {
            'openocd': {
                'callback': openocd,
                'help': 'Run openocd from current path',
                'options': [
                    {
                        'names': ['--openocd-scripts', '--openocd_scripts'],
                        'help':
                        ('Script directory for openocd cfg files.\n'),
                        'default':
                        None,
                    },
                    {
                        'names': ['--openocd-commands', '--openocd_commands'],
                        'help':
                        ('Command line arguments for openocd.\n'),
                        'default': None,
                    }
                ],
                'order_dependencies': ['all', 'flash'],
            },
            'gdb': {
                'callback': gdb,
                'help': 'Run the GDB.',
                'options': [
                    {
                        'names': ['--gdb-tui', '--gdb_tui'],
                        'help':
                        ('run gdb in TUI mode\n'),
                        'default':
                        None,
                    }, gdbinit, fail_if_openocd_failed
                ],
                'order_dependencies': ['all', 'flash'],
            },
            'gdbgui': {
                'callback': gdbui,
                'help': 'GDB UI in default browser.',
                'options': [
                    {
                        'names': ['--gdbgui-port', '--gdbgui_port'],
                        'help':
                        ('The port on which gdbgui will be hosted. Default: 5000\n'),
                        'default':
                        None,
                    }, gdbinit, fail_if_openocd_failed
                ],
                'order_dependencies': ['all', 'flash'],
            },
            'gdbtui': {
                'callback': gdbtui,
                'help': 'GDB TUI mode.',
                'options': [gdbinit, fail_if_openocd_failed],
                'order_dependencies': ['all', 'flash'],
            },
            'post_debug': {
                'callback': post_debug,
                'help': 'Utility target to read the output of async debug action and stop them.',
                'options': [
                    {
                        'names': ['--block', '--block'],
                        'help':
                        ('Set to 1 for blocking the console on the outputs of async debug actions\n'),
                        'default': 0,
                    },
                ],
                'order_dependencies': [],
            },
        },
    }

    return debug_actions