#!/usr/bin/python3
"""install.py

- copy files from to_system into system directories
- set host name / network settings from boxtools/cfg file
- and many more
"""

if bytes == str:
    raise NotImplementedError('python2 not supported')

import sys
import os
import filecmp
import re
import types
import socket
import tempfile
from pathlib import Path
from subprocess import Popen, PIPE
from ipaddress import IPv4Interface
from os.path import getmtime, exists
from gitea import change_to_gitea


def exit():
    print('please restart ./install.py again')
    sys.exit()


try:
    import serial
except ImportError:
    if 'yes'.startswith(input('install pyserial? [y]')):
        os.system('sudo apt update')
        os.system('sudo apt install python3-pip')
        os.system('sudo pip3 install --break-system-packages pyserial')
    serial = None

try:
    from utils import BoxInfo, check_service, unix_cmd, change_firewall, UndefinedConfigFile, convert_cfg
except ImportError:
    if 'yes'.startswith(input('install netifaces? [y]')):
        os.system('sudo pip3 install --break-system-packages netifaces')
    serial = None

if serial is None:
    exit()


TOOLS = BoxInfo.TOOLS
BOX_TYPES = {'ionopi', 'ionopimax', 'control-box', 'bare-apu', 'dual-eth-rpi'}

more_info = False

DEL = '__to_delete__'
STARTUP_TEXT = TOOLS / 'startup_display.txt'

COMMENT = "; please refer to README.md for help"

TEMPLATES = {}
TEMPLATES['bare-apu'] = f"""{COMMENT}

[BOX]
type=%(typ)s
MAC=%(mac)s

[NETWORK]
eth0=wan
eth1=192.168.2.2
eth2=192.168.3.3
eth3=192.168.127.254

[ROUTER]
3001=192.168.127.254:3001
"""

TEMPLATES['control-box'] = f"""{COMMENT}

[BOX]
type=%(typ)s
MAC=%(mac)s

[NETWORK]
eth0=wan
eth1=192.168.1.1
eth2=192.168.2.2
eth3=192.168.3.3

[DISPLAY]
line0=startup...
line1=HOST
line2=ADDR
"""

TEMPLATES['dual-eth-rpi'] = f"""{COMMENT}

[BOX]
type=%(typ)s
MAC=%(mac)s

[NETWORK]
end0=wan
%(mac2)s=192.168.1.1
"""

GENERIC_TEMPLATE = f"""{COMMENT}

[BOX]
type=%(typ)s
MAC=%(mac)s
"""

DHCP_HEADER = """
default-lease-time 600;
max-lease-time 7200;
authoritative;
"""

ROUTER_SERVICE = f"""[Unit]
Description = Routing to locally connected hardware
After = network.target

[Service]
ExecStart = /usr/bin/python3 {TOOLS}/router.py

[Install]
WantedBy = multi-user.target
"""

FRAPPY_SERVICE = """[Unit]
Description = Running frappy server
After=waitboot.service

[Service]
Type=simple
Environment=PYTHONPATH=/home/l_samenv/.local/lib/python3.11/site-packages/
ExecStart = /home/l_samenv/boxtools/start_frappy

[Install]
WantedBy = default.target
"""

DISPLAY_SERVICE = f"""[Unit]
Description = status display
After = network.target

[Service]
User = root
ExecStart = /usr/bin/python3 {TOOLS}/display.py -d

[Install]
WantedBy = multi-user.target
"""

DISPLAY_SERVICE = f"""[Unit]
Description = status display
After = network.target

[Service]
User = root
ExecStart = /usr/bin/python3 {TOOLS}/display.py -d

[Install]
WantedBy = multi-user.target
"""

BOXWEB_SERVICE = """[Unit]
Description = Web service for local GUI on a box
After = waitboot.target

[Service]
ExecStart = /usr/bin/python /home/l_samenv/boxweb/flaskserver.py {page} {port}

[Install]
WantedBy = default.target
"""

pip_requirements = {
    'root': {},
    'l_samenv': {},
}


box = BoxInfo()
box.hostname_changed = False
dhcp_server_cfg = []

TO_SYSTEM = TOOLS / 'to_system', TOOLS / f'{box.typ}_system'


def do_cmd(*command, sudo=True):
    unix_cmd(*command, execute=doit, sudo=sudo)
    show.dirty = True


def frappy(cfg=None, port=None, requirements='', **kwds):
    if not cfg:
        return False, None
    req = pip_requirements['l_samenv']
    if requirements:
        req[cfg] = '\n'.join(requirements.split(','))
    with open('/home/l_samenv/frappy/requirements.txt') as f:
        req['frappy main'] = f.read()
    return False, FRAPPY_SERVICE


def router(firewall=False, **opts):
    if firewall:
        active, enabled = check_service('nftables')
        ports = {22}
        if opts:
            for port in firewall.split(','):
                ports.add(int(port))
            for key in opts:
                try:
                    ports.add(int(key))
                except ValueError:
                    pass
            ports.update((1110, 1111, 1112))
        if change_firewall(True, ports, doit):
            show.dirty = True
    elif change_firewall(False, set(), doit):
        show.dirty = True
    if not opts:
        return True, None
    try:
        os.remove(TO_SYSTEM[0] / 'etc/nftables.conf')
        with open(TOOLS / 'requirements.txt') as f:
            pip_requirements['root']['tools'] = f.read()
    except FileNotFoundError:
        pass
    return True, ROUTER_SERVICE


def display_update(cfg):
    text = '\n'.join(cfg.get('startup_text', '').split('|')[:3])
    text = text.replace('HOST', box.hostname) \
               .replace('ADDR', box.macaddr) + '\n'
    if write_when_new(STARTUP_TEXT, text):
        print('change startup text')
        if doit:
            os.rename(STARTUP_TEXT, STARTUP_TEXT + '.todo')
        return True
    return False


def display(**opts):
    if not opts:
        return True, None
    return True, DISPLAY_SERVICE


def pip():
    for user, requirements in pip_requirements.items():
        if not requirements:
            continue
        if user == 'root':
            tmpname = '/root/pip_requirements.tmp'
            pipcmd = ['sudo pip3 install -r', tmpname]
        else:
            tmpname = f'/home/{user}/pip_requirements.tmp'
            pipcmd = ['pip3 install --user --break-system-packages -r', tmpname]
        filename = tmpname.replace('.tmp', '.txt')
        content = ''.join('# --- for %s ---\n%s\n' % kv for kv in requirements.items())
        if content:
            if write_when_new(filename, content, user=='root'):
                if doit:
                    os.rename(filename, tmpname)
                    if os.system(' '.join(pipcmd)) == 0:
                        os.rename(tmpname, filename)
                    else:
                        os.remove(tmpname)
                else:
                    print(' '.join(pipcmd))
                show.dirty = True


def boxweb(port=8080, page=None):
    port = int(port)
    servicecfg = None if page is None else BOXWEB_SERVICE.format(port=port, page=page)
    return port <= 1024, servicecfg


SERVICES = dict(router=router, display=display, frappy=frappy, boxweb=boxweb)
AS_ROOT = {'router', 'display'}


def write_when_new(filename, content, as_root=False, ignore_reduction=False):
    if content is None:
        lines = []
    else:
        if not content.endswith('\n'):
            content += '\n'
        lines = content.split('\n')
    try:
        with open(filename) as fil:
            old = fil.read()
    except FileNotFoundError:
        old = None
    #except Exception as e:
    #    print('can not read', filename, '-> do not check')
    #    return False
    if old == content:
        return False
    if ignore_reduction:
        content_set = set(v for v in lines if not v.startswith('#'))
        old_set = set(v for v in (old or '').split('\n') if not v.startswith('#'))
        content_set -= old_set
        if content_set:
            print(f"missing in {filename}: {(', '.join(content_set - old_set))}")
        else:
            return False
    if doit:
        if lines:
            unix_cmd(f'mkdir -p {Path(filename).parent}', sudo=as_root)
            with tempfile.NamedTemporaryFile('w') as fil:
                fil.write(content)
                fil.flush()
                unix_cmd('cp', fil.name, filename, sudo=as_root)
                unix_cmd('chmod 0644', filename, sudo=as_root)
        else:
            unix_cmd('rm', '-f', filename, sudo=as_root)
    elif more_info:
        print('.' * 80)
        print('changes in', filename)
        old = [] if old is None else old.split('\n')
        top_lines = 0  # in case of empty loop
        for top_lines, (ol, ll) in enumerate(zip(old, lines)):
            if ol != ll:
                break
        bottom_lines = 0
        for bottom_lines, (ol, ll) in enumerate(zip(reversed(old[top_lines:]), reversed(lines[top_lines:]))):
            if ol != ll:
                break
        if bottom_lines == 0:
            old.append('')
            lines.append('')
            bottom_lines += 1
        print("===")
        print('\n'.join(old[:top_lines]))
        print('<<<')
        print('\n'.join(old[top_lines:-bottom_lines]))
        print('---')
        print('\n'.join(lines[top_lines:-bottom_lines]))
        print('>>>')
        print('\n'.join(old[-bottom_lines:-1]))
        print("===")
        print('.' * 80)
    return content


def replace_in_file(filename, pat, repl):
    """find pattern <prev> in content of filename

    find regexp pattern <pat> in content of file
    - if it does not match exactly once, an error is raised
    - exchange group 1 by repl
    - return True when result is changed, or False when not

    doit determines, whether the file is really changed
    """
    with open(filename) as f:
        content = f.read()

    success = []

    def fun(match, count=[]):
        if success:
            raise ValueError(f'{pat} matches multiple times in {filename}')
        part = match.group(0)
        match = match.re.match(part)
        fr, to = match.span(1)
        result = part[:fr] + repl + part[to:]
        if result != part:
            print(f'in {filename} replace {part} -> {result}')
        success.append(result != part)
        return result

    newcontent = re.sub(pat, fun, content)

    if not success:
        raise ValueError(f'{pat} not in {filename}')

    write_when_new(filename, newcontent, as_root=True)
    return success[0]


def create_if(name, cfg):
    if cfg == 'off':
        result = None
    elif cfg.startswith('wan') or cfg == 'dhcp':
        if box.main_if != name:
            print(box.main_if, name)
            raise ValueError('can not have more than one WAN/DHCP port')
        box.main_if = name
        # default: all <= 192.0.0.0
        # others have to be added explicitly
        dhcp_server_cfg.append(('0.0.0.0/128.0.0.0', []))
        dhcp_server_cfg.append(('128.0.0.0/192.0.0.0', []))
        for nw in cfg.split(',')[1:]:
            nw = IPv4Interface(nw).network
            dhcp_server_cfg.append((nw.with_netmask, []))
        result = f"allow-hotplug {name}\niface {name} inet dhcp"
    else:
        cfgip = IPv4Interface(cfg)
        network = cfgip.network
        if network.prefixlen == 32:  # or no prefix specified
            otherip = IPv4Interface('%s/24' % cfgip.ip)
            network = otherip.network
            if str(cfgip.ip).endswith('.1'):
                cfgip = network.network_address + 2
            else:
                cfgip = network.network_address + 1
            dhcp_server_cfg.append((network.with_netmask, [(str(otherip.ip), str(otherip.ip))]))
            addr = str(cfgip)
        else:  # subnet with multiple adresses -> static adresses only. dhcp range not yet implemented
            addr = str(cfgip.ip)
        # result['NETMASK'] = network.netmask
        result = f"allow-hotplug {name}\niface {name} inet static\n    address {addr}/{network.prefixlen}"
    if result:
        return result + '\n'


def walk_dir(action, srcpath, dstroot, files):
    if not files:
        return
    action.srcpath = srcpath = Path(srcpath)
    action.dstpath = dstpath = dstroot / srcpath
    match, mismatch, missing = filecmp.cmpfiles(srcpath, dstpath, files)
    if mismatch:
        newer = [f for f in mismatch if getmtime(dstpath / f) > getmtime(srcpath / f)]
        if newer:
            action.newer(newer)
        if len(newer) < len(mismatch):
            newer = set(newer)
            action.older([f for f in mismatch if f not in newer])
    if missing:
        if DEL in missing:
            missing.remove(DEL)
            with open(srcpath / DEL) as fil:
                to_delete = []
                for fname in fil:
                    fname = fname.strip()
                    if fname and exists(dstpath / fname):
                        if (srcpath / fname).exists():
                            print('ERROR: %s in %s, but also in repo -> ignored' % (fname, DEL))
                        else:
                            to_delete.append(fname)
                action.delete(to_delete)
        if missing:
            action.missing(missing)


def walk(action):
    action.as_root = True
    for rootpath in TO_SYSTEM:
        if not rootpath.exists():
            continue
        os.chdir(rootpath)
        for srcpath, _, files in os.walk('.'):
            walk_dir(action, srcpath, Path('/'), files)
    os.chdir(TOOLS / 'to_home')
    action.as_root = False
    for srcpath, _, files in os.walk('.'):
        walk_dir(action, srcpath, Path.home(), files)


class Walker:
    srcpath = None
    dstpath = None
    as_root = None


class Show(Walker):
    dirty = False

    def diff(self, title, files):
        self.dirty = True
        if more_info:
            for f in files:
                if f.endswith(more_info):
                    print('diff %s %s' % (self.srcpath / f, self.dstpath / f))
                    print('.' * 80)
        else:
            print('%s %s:\n  %s' % (title, self.dstpath, ' '.join(files)))

    def show(self, title, srcpath, files):
        self.dirty = True
        if more_info:
            for f in files:
                print('cat %s' % (srcpath / f))
                print('.' * 80)
        else:
            print('%s %s:\n  %s' % (title, self.dstpath, ' '.join(files)))

    def newer(self, files):
        self.show('get from', self.srcpath, files)

    def older(self, files):
        self.show('replace in', self.srcpath, files)

    def missing(self, files):
        self.show('install in', self.srcpath, files)

    def delete(self, files):
        self.show('remove from', self.dstpath, files)


class Do(Walker):
    def newer(self, files):
        unix_cmd('mkdir', '-p', str(self.dstpath), sudo=self.as_root)
        unix_cmd('cp', *(str(self.srcpath / f) for f in files), str(self.dstpath),
                 sudo=self.as_root)

    older = newer

    missing = newer

    def delete(self, files):
        unix_cmd('rm', '-f', *(str(self.dstpath / f) for f in files))


def handle_config():
    dhcp_server_cfg.clear()
    try:
        config = box.read_config()
    except UndefinedConfigFile as e:
        print(f'{box.cfgfile} not found', e)

    if box.oldcfg:
        print(f'convert {box.cfgfile} to {convert_cfg(box.cfgfile, box.macaddr)}')
        config = box.read_config()

    cfgfile = box.cfgfile
    newhostname = box.hostname
    if cfgfile:
        if box.hwtype != 'apu':
            typ = config.get('BOX', {}).get('type')
            if typ:
                if typ not in BOX_TYPES:
                    raise ValueError(f'unknown type={typ} defined in BOX section')
                box.typ = typ
            elif box.typ == 'cm4':
                print('WARNING: missing type in BOX section')
                print('This is a cm4 so guess its a dual-eth-rpi')
                box.typ = 'dual-eth-rpi'
            elif box.typ == 'cm3':
                print('WARNING: missing type in BOX section')
                print('This is a cm3 so guess its a ionopimax')
                box.typ = 'ionopimax'
        print('box type:', box.typ, ' mac addr:', box.macaddr)
        print('---')
    else:
        template_args = {'mac': box.macaddr}
        if box.typ == 'apu':
            # determine if display is present
            disp = serial.Serial('/dev/ttyS1', baudrate=115200, timeout=1)
            disp.write(b'\x1b\x1b\x01\xf3')
            display_available = disp.read(8)[0:4] == b'\x1b\x1b\x05\xf3'
            if display_available:
                box.typ = 'control=box'
            else:
                box.typ = 'bare-apu'
        elif box.typ == 'cm4':
            box.typ = 'dual-eth-rpi'
            print('This is a cm4, so guess its a dual-eth-rpi - please check type in created cfg file')
            template_args['mac2'] = 'enx?'
            for addr in box.network_interfaces:
                if addr.startswith('enx'):
                    template_args['mac2'] = addr
            print(template_args)
        elif box.typ == 'cm3':
            print('This is a cm3 so guess its a ionopimax - please check type in created cfg file')
            box.typ = 'ionopimax'
        elif box.typ == 'rpi':
            print('This is a simple rpi, so guess its a ionopi - please check type in created cfg file')
            box.typ = 'ionopi'
        template = TEMPLATES.get(box.typ)
        if template is None:
            box.typ = box.typ or 'unknown-box'
            template = GENERIC_TEMPLATE
        template_args['typ'] = box.typ
        template = template % template_args

        print('no cfg file found for this', box.typ,
              f'with mac address {box.macaddr} (hostname={box.hostname})')
        newhostname = input('enter host name: ')
        if not newhostname:
            print('no hostname given')
            return False
        cfgfile = BoxInfo.CFGDIR / f'{newhostname}.cfg'
        with open(cfgfile, 'w') as f:
            f.write(template)
        config = box.read_config()
        cfgfile = box.cfgfile
    if box.hostname_changed or box.hostname != newhostname:
        box.hostname_changed = True
        if cfgfile:
            newhostname = cfgfile.stem.split('_')[0]
        if doit:
            print('bash sethostname.sh')
            unix_cmd('bash', f'{TOOLS}/sethostname.sh')
        else:
            if cfgfile:
                print('replace host name %r by %r' % (box.hostname, newhostname))
                show.dirty = True
        config = box.read_config()
    box.hostname = newhostname
    if cfgfile is None:
        return False
    to_start = {}  # dict <service> of <action>, <as_root>
    ifname = ''
    try:
        netcfg = config.get('NETWORK', {})
        if netcfg:  # when not network is specified, do not handle network at all
            for name in netcfg:
                if name not in box.network_interfaces:
                    print(f'{name} is currently not a valid network interface - skip')
                    continue
            for ifname in box.network_interfaces:
                content = create_if(ifname, netcfg.get(ifname, 'off'))
                # content = '\n'.join('%s=%s' % kv for kv in content.items())
                todo = write_when_new(f'/etc/network/interfaces.d/{ifname}', content, as_root=True)
                if todo and not more_info:
                    print('change', ifname)
                    show.dirty = True
                    to_start[ifname] = 'if_restart', True
            if dhcp_server_cfg:
                content = [DHCP_HEADER]
                for subnet, rangelist in dhcp_server_cfg:
                    try:
                        adr, mask = subnet.split('/')
                    except Exception as e:
                        print(subnet, repr(e))
                        continue
                    content.append('subnet %s netmask %s {\n' % (adr, mask))
                    #content.append('    option netmask %s;\n' % mask)
                    for rng in rangelist:
                        content.append('    range %s %s;\n' % rng)
                    content.append('}\n')
                content = ''.join(content)
                todo = write_when_new('/etc/dhcp/dhcpd.conf', content, as_root=True)
                if todo:
                    print('change dhcpd.conf')
                    to_start['isc-dhcp-server'] = 'restart', True
                    show.dirty = True
                try:
                    if replace_in_file(
                            '/etc/default/isc-dhcp-server', r'INTERFACESv4="(.*)"', ' '.join(
                            [n for n in box.network_interfaces if n != box.main_if])):
                        show.dirty = True
                except FileNotFoundError:
                    if 'yes'.startswith(input('install isc-dhcp-server? [y]')):
                        unix_cmd('apt-get install isc-dhcp-server')
                    exit()
            elif doit:
                unix_cmd('systemctl stop isc-dhcp-server')
                unix_cmd('systemctl disable isc-dhcp-server')
        displaycfg = config.get('DISPLAY')
        if displaycfg and display_update(displaycfg):
             to_start['display'] = 'restart', True
        if change_to_gitea(doit):
            show.dirty = True
    except Exception as e:
        print('ERROR: can not handle %s %s: %r' % (box.hostname, ifname, e))
        raise
        # return False

    reload_systemd = set()
    for service, service_func in SERVICES.items():
        section = service.upper()
        section_dict = config.get(section, {})
        as_root, servicecfg = service_func(**section_dict)
        active, enabled = check_service(service, as_root=as_root)
        if servicecfg is None:
            if active or enabled:
                check_service(service, False, doit, as_root=as_root)
                show.dirty = True
            continue
        else:
            if not enabled:
                to_start[service] = 'enable', as_root
            elif not active:
                to_start[service] = 'restart', as_root
        if as_root:
            systemdir = Path('/etc/systemd/system')
        else:
            systemdir = Path('~/.config/systemd/user').expanduser()
        if write_when_new(systemdir / f'{service}.service', servicecfg, as_root=as_root):
            show.dirty = True
            reload_systemd.add(as_root)
            if servicecfg and to_start.get('service') is None:
                to_start[service] = 'restart', as_root

    if 'dialout' not in unix_cmd('id l_samenv'):
        do_cmd('usermod -a -G dialout l_samenv')
    pip()
    for as_root in reload_systemd:
        if as_root:
            do_cmd('systemctl daemon-reload', sudo=True)
        else:
            do_cmd('systemctl --user daemon-reload', sudo=False)
    for service, (action, _) in to_start.items():
        show.dirty = True
        if action == 'if_restart':
            do_cmd(f'ifconfig {service} down')
    for service, (action, as_root) in to_start.items():
        if action == 'if_restart':
            do_cmd(f'ifconfig {service} up')
        else:
            if action == 'restart':  # else 'enable'
                do_cmd('systemctl', 'restart', service, sudo=as_root)
            if not as_root:
                do_cmd('loginctl enable-linger', sudo=True)
            do_cmd('systemctl', 'enable', service, sudo=as_root)

    if box.change_if_names:
        print('interface name system has to be changed from enp*s0 to eth*')
        if replace_in_file('/etc/default/grub',
                           r'GRUB_CMDLINE_LINUX_DEFAULT="quiet(.*)"',
                           ' net.ifnames=0'):
            do_cmd('update-grub')

    result = [f'config file:\n  {cfgfile}']
    for section, section_dict in config.items():
        result.append(section)
        for key, value in section_dict.items():
            result.append(f'  {key} = {value}')
    result.append('')
    return '\n'.join(result)


doit = False
print(' ')
show = Show()
walk(show)
result = handle_config()

if not result:
    print('fix first above errors')
else:
    if show.dirty:
        print('---')
        answer = input('enter "y(es)" to do above or "m(ore)" for more info: ')
        if not answer:
            print('cancel')
        elif 'yes'.startswith(answer.lower()):
            doit = True
            handle_config()
            walk(Do())
            unix_cmd(f'rm -f {TOOLS / "current"}')
            with open(TOOLS / 'current', 'w') as f:
                f.write(result)
        elif 'more'.startswith(answer.lower()):
            more_info = True
            walk(show)
            result = handle_config()
    else:
        print('nothing to do')