#!/usr/bin/env python3

# SPDX-FileCopyrightText: (C) 2025 Enno Tensing <tenno+containerctl@suij.in>
#
# SPDX-License-Identifier: GPL-2.0-only

"""Util module holding Container and related objects."""

from dataclasses import dataclass
from typing import Self, TypeAlias

from log import Log

ConfigValue: TypeAlias = str | dict | list | bool | None


class ConfigError(Exception):
    """An invalid config."""

    message: str

    def __init__(self, message: str = "") -> None:
        """Create Exception object."""
        self.message = message
        super().__init__(message)

    def __str__(self) -> str:
        """Convert Exception object to a string."""
        return f"Configuration error: {self.message}"


def maybe(json: dict, key: str) -> ConfigValue:
    """Maybe get a value."""
    try:
        return json[key]
    except KeyError:
        return None


def maybe_or(json: dict, key: str, _or: ConfigValue) -> ConfigValue:
    """Maybe get a value, but return _or if it is None."""
    val = maybe(json, key)
    if val is None or not isinstance(val, type(_or)):
        return _or
    return val


def trim(s: str) -> str:
    """Remove sequential whitespace."""
    s = s.replace("\t ", "\t")
    s = s.replace("\t\\\n", "  ")
    while "  " in s:
        s = s.replace("  ", " ")
    return s


@dataclass
class Cgroup:
    """cgroup Config."""

    config: list
    parent: str
    namespace: str
    how: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if val is None:
            return cls([], "", "", "")

        if not isinstance(val, dict):
            logger.log_warning("cgroup Config is invalid!")
            return cls([], "", "", "")

        config = maybe_or(val, "config", [])
        parent = maybe_or(val, "parent", "")
        namespace = maybe_or(val, "namespace", "")
        how = maybe_or(val, "how", "")

        if not isinstance(config, list):
            logger.log_warning("Config key in cgroup Config is invalid!")
            config = []

        if not isinstance(parent, str):
            logger.log_warning("Parent key in cgroup Config is invalid!")
            parent = ""

        if not isinstance(namespace, str):
            logger.log_warning("Namespace key in cgroup Config is invalid!")
            namespace = ""

        if not isinstance(how, str):
            logger.log_warning("How key in cgroup Config is invalid!")
            how = ""

        if how == "split" and parent != "":
            logger.log_warning(
                "Split cgroups can not be combined with a cgroup parent!"
            )
            parent = ""

        return cls(config, parent, namespace, how)

    def command(self) -> str:
        """Option for podman container create."""
        cmd = ""
        seperator = " \\\n"
        cmd += seperator.join(
            [f"\t--cgroup-conf={option}{seperator}" for option in self.config]
        )
        if self.parent != "":
            cmd += f"\t--cgroup-parent={self.parent}{seperator}"
        if self.namespace != "":
            cmd += f"\t--cgroupns={self.namespace}{seperator}"
        if self.how != "":
            cmd += f"\t--cgroups={self.how}{seperator}"

        return cmd


@dataclass
class Cpu:
    """CPU Accounting."""

    period: str
    quota: str
    shares: str
    number: str
    cpuset_cpus: str
    cpuset_mems: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if val is None:
            return cls("", "", "", "", "", "")

        if not isinstance(val, dict):
            logger.log_warning("cpu Config is invalid!")
            return cls("", "", "", "", "", "")

        period = maybe_or(val, "period", "")
        quota = maybe_or(val, "quota", "")
        shares = maybe_or(val, "shares", "")
        number = maybe_or(val, "number", "")
        cpuset = maybe_or(val, "cpuset", {})
        cpuset_cpus = ""
        cpuset_mems = ""
        if len(cpuset) != 0:
            cpuset_cpus += maybe_or(cpuset, "cpus", "")
            cpuset_mems += maybe_or(cpuset, "mems", "")

        return cls(
            period,
            quota,
            shares,
            number,
            cpuset_cpus,
            cpuset_mems,
        )

    def command(self) -> str:
        """Option for podman container create."""
        cmd = ""
        seperator = " \\\n"
        if self.period != "":
            cmd += f"\t--cpu-period={self.period}{seperator}"
        if self.quota != "":
            cmd += f"\t--cpu-quota={self.quota}{seperator}"
        if self.shares != "":
            cmd += f"\t--cpu-shares={self.shares}{seperator}"
        if self.number != "":
            cmd += f"\t--cpus={self.number}{seperator}"
        if self.cpuset_cpus != "":
            cmd += f"\t--cpuset-cpus={self.cpuset_cpus}{seperator}"
        if self.cpuset_mems != "":
            cmd += f"\t--cpuset-mems={self.cpuset_mems}{seperator}"

        return cmd


@dataclass
class Memory:
    """Memory accounting."""

    limit: str
    reservation: str
    swap: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if val is None:
            return cls("", "", "")

        if not isinstance(val, dict):
            logger.log_warning("memory Config is invalid!")
            return cls("", "", "")

        limit = maybe_or(val, "limit", "")
        reservation = maybe_or(val, "reservation", "")
        swap = maybe_or(val, "swap", "")
        if limit == "":
            return cls("", "", "")
        return cls(limit, reservation, swap)

    def command(self) -> str:
        """Option for podman container create."""
        if self.limit == "":
            return ""
        cmd = ""
        seperator = " \\\n"

        cmd += f"\t--memory={self.limit}{seperator}"
        if self.reservation != "":
            cmd += f"\t--memory-reservation={self.reservation}{seperator}"
        if self.swap != "":
            cmd += f"\t--memory-swap={self.swap}{seperator}"

        return cmd


@dataclass
class Accounting:
    """Resource Accounting."""

    cgroup: Cgroup
    cpu: Cpu
    memory: Memory

    @classmethod
    def from_json(cls, data: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if data is None:
            return cls(
                Cgroup.from_json(None, logger),
                Cpu.from_json(None, logger),
                Memory.from_json(None, logger),
            )

        cgroup_data = maybe(data, "cgroup")
        cpu_data = maybe(data, "cpu")
        memory_data = maybe(data, "memory")
        cgroup = Cgroup.from_json(cgroup_data, logger)
        cpu = Cpu.from_json(cpu_data, logger)
        memory = Memory.from_json(memory_data, logger)
        return cls(cgroup, cpu, memory)

    def command(self) -> str:
        """Options for podman container create."""
        cgroup = self.cgroup.command()
        cpu = self.cpu.command()
        memory = self.memory.command()
        return cgroup + cpu + memory


@dataclass
class Volume:
    """Container Volume."""

    name: str
    path: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> list | None:
        """Create from JSON."""
        if val is None:
            return None
        if not isinstance(val, dict):
            logger.log_warning("Volume key is present, but malformed.")
            return None
        return [cls(key, value) for key, value in val.items()]

    def is_host_volume(self) -> bool:
        """Check if this Volume is a named or a host volume."""
        return self.name.startswith("/") or self.name.startswith(".")

    def command(self) -> str:
        """Option for podman container create."""
        return f"--volume {self.name}:{self.path}"

    def create(self) -> str:
        """Create volume, if it does not exist."""
        if self.is_host_volume():
            # A HOST-DIR starting with a slash or dot is interpreted as a
            # directory or file on the host machine. Since the script should
            # not modify things outside its own tree, i.e.
            # /var/lib/containerctl, ignore it.
            return ""
        cmd = f"# Create volume {self.name}\n"
        cmd += f"if ! podman volume exists '{self.name}' 2> /dev/null\n"
        cmd += "then\n"
        cmd += f"\tpodman volume create '{self.name}'\n"
        cmd += "fi\n"
        return cmd

    def remove(self) -> str:
        """Remove volume if it exists."""
        if self.is_host_volume():
            # As with create, don't touch the host system
            return ""
        cmd = f"# Remove volume {self.name}\n"
        cmd += f"if podman volume exists '{self.name}' 2> /dev/null\n"
        cmd += "then\n"
        cmd += f"\tpodman volume rm '{self.name}'\n"
        cmd += "fi\n"
        return cmd


@dataclass
class Secret:
    """Container Secret."""

    name: str
    secret_type: str
    target: str
    options: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> list | None:
        """Create from JSON."""
        if val is None:
            return None
        if not isinstance(val, dict):
            logger.log_warning("Secret key is present, but malformed!")
            return None
        secrets = []
        for key in val:
            if not isinstance(val[key], dict):
                logger.log_warning(f"Secret {key} is malformed!")
                continue
            name = key
            secret_type = maybe_or(val[key], "type", "")
            target = maybe_or(val[key], "target", "")
            options = maybe_or(val[key], "options", "")
            if options is None:
                options = ""
            secrets.append(
                cls(name, str(secret_type), str(target), str(options))
            )

        return secrets

    def command(self) -> str:
        """Option for podman container create."""
        cmd = (
            f"--secret {self.name},:"
            f"type={self.secret_type},"
            f"target={self.target}"
        )
        # Not a password, ruff...
        if self.secret_type == "mount" and self.options != "":  # noqa: S105
            cmd = f"{cmd},{self.options}"

        return cmd

    def create(self) -> str:
        """Create secret if it does not exist."""
        cmd = f"# Create secret {self.name}\n"
        cmd += f"if ! podman secret exists '{self.name}' 2> /deb/null\n"
        cmd += "then\n"
        cmd += "\thead /dev/urandom \\\n"
        cmd += "\t\t| tr -dc A-Za-z0-9 \\\n"
        cmd += "\t\t| head -c 128 \\\n"
        cmd += f"\t\t| podman secret create '{self.name}' -\n"
        cmd += "fi\n"
        return cmd

    def remove(self) -> str:
        """Remove secret if it exists."""
        cmd = f"# Remove secret {self.name}\n"
        cmd += f"if podman secret exists '{self.name}' 2> /dev/null\n"
        cmd += "then\n"
        cmd += f"\tpodman secret rm '{self.name}'\n"
        cmd += "fi\n"
        return cmd


@dataclass
class Environment:
    """Container environment."""

    variables: list
    file: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if val is None:
            return cls([], "")
        if not isinstance(val, dict):
            logger.log_warning("Environment key is present, but malformed!")
            return cls([], "")
        return cls([f"{key}='{value}'" for key, value in val.items()], "")

    def command(self) -> str:
        """Option for podman container create."""
        return f"--env-file={self.file}"

    def create(self) -> str:
        """Create env file."""
        cmd = f"# Create env-file {self.file}\n"
        for var in self.variables:
            escaped_var = var.replace("'", "%b")
            cmd += f"printf '{escaped_var}\\n' \"'\" \"'\" >> '{self.file}'\n"

        return cmd

    def remove(self) -> str:
        """Remove env file."""
        cmd = f"# Remove env-file {self.file}\n"
        cmd += f"if [ -e '{self.file}' ]\n"
        cmd += "then\n"
        cmd += f"\trm '{self.file}'\n"
        cmd += "fi\n"
        return cmd


@dataclass
class Ports:
    """Container Ports."""

    tcp_ports: list
    udp_ports: list

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if val is None:
            return cls([], [])
        if not isinstance(val, dict):
            logger.log_warning("Ports key is present, but malformed!")
            return cls([], [])
        tcp_ports = maybe(val, "tcp")
        udp_ports = maybe(val, "udp")
        if not isinstance(tcp_ports, list):
            logger.log_warning("Key tcp_ports is not an array!")
            return cls([], [])
        if not isinstance(udp_ports, list):
            logger.log_warning("Key udp_ports is not an array!")
            return cls([], [])
        return cls(tcp_ports, udp_ports)

    def command(self) -> str:
        """Option for podman container create."""
        ports = ""
        seperator = " \\\n"
        ports += seperator.join(
            [f"\t--port {port}/tcp" for port in self.tcp_ports]
        )
        ports += seperator
        ports += seperator.join(
            [f"\t--port {port}/udp" for port in self.udp_ports]
        )
        ports += seperator
        return ports


@dataclass
class Network:
    """Container Network."""

    mode: str
    options: list

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if val is None or not isinstance(val, dict):
            logger.log_error("Network configuration is missing or malformed!")
            return cls("", [])
        mode = maybe(val, "mode")
        options = maybe(val, "options")
        if mode is None or options is None or not isinstance(options, list):
            err = "Network configuration is missing or has malformed elements!"
            logger.log_error(err)
            return cls("", [])
        return cls(str(mode), options)

    def command(self) -> str:
        """Option for podman container create."""
        if self.mode == "":
            return ""
        cmd = f"--network={self.mode}"
        opts = ",".join(self.options)
        if opts != "":
            cmd += f":{opts}"
        return cmd


@dataclass
class Image:
    """Container Image."""

    registry: str
    image: str
    tag: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self | None:
        """Create from JSON."""
        if val is None or not isinstance(val, dict):
            logger.log_error("Image key either not present or malformed!")
            return None
        registry = maybe_or(val, "registry", "")
        image = maybe_or(val, "image", "")
        tag = maybe_or(val, "tag", "")
        return cls(str(registry), str(image), str(tag))

    def command(self) -> str:
        """Option for podman container create."""
        return f"{self.registry}/{self.image}:{self.tag}"


@dataclass
class Capability:
    """Container Capability."""

    cap: str
    mode: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> list | None:
        """Create from JSON."""
        if val is None or not isinstance(val, dict):
            logger.log_warning(
                "Capabilities key is either missing or malformed!"
            )
            return None
        add = [cls(value, "add") for value in val["add"]]
        drop = [cls(value, "drop") for value in val["drop"]]
        return add + drop

    def command(self) -> str:
        """Option for podman container create."""
        return f"--cap-{self.mode}={self.cap}"


@dataclass
class Dns:
    """Container DNS."""

    servers: list
    search: str

    @classmethod
    def from_json(cls, val: ConfigValue, logger: Log) -> Self:
        """Create from JSON."""
        if val is None or not isinstance(val, dict):
            logger.log_error("DNS Key is either missing or malformed!")
            return cls([], "")
        search = maybe_or(val, "search", "")
        servers = maybe(val, "servers")
        if not isinstance(servers, list):
            logger.log_error("Servers key is not an array!")
            return cls([], "")
        return cls(servers, str(search))

    def command(self) -> str:
        """Option for podman container create."""
        if len(self.servers) == 0 and self.search == "":
            return ""
        if len(self.servers) == 0:
            return f"--dns-search={self.search}"
        if self.search == "":
            return f"--dns={','.join(self.servers)}"

        cmd = f"--dns-search={self.search} \\\n\t--dns="
        cmd += ",".join(self.servers)

        return cmd


class Container:
    """Container."""

    name: str
    image: Image
    privileged: bool
    read_only: bool
    replace: bool
    restart: str
    pull_policy: str
    timezone: str
    network: Network
    dns: Dns
    ports: Ports
    env: Environment | None
    secrets: list | None
    volumes: list | None
    capabilities: list | None
    accounting: Accounting

    def __init__(self, json: dict, logger: Log | None = None) -> None:
        """Create from JSON."""
        if logger is None:
            logger = Log("/dev/stdout")
        name = maybe(json, "name")
        if name is None:
            logger.log_error("No container name set, aborting!")
            return
        image = maybe(json, "image")
        if image is None:
            logger.log_error("No image set, aborting!")
            return
        privileged = maybe(json, "privileged")
        read_only = maybe(json, "read_only")
        replace = maybe(json, "replace")
        pull_policy = maybe_or(json, "pull_policy", "always")
        restart = maybe_or(json, "restart", "no")
        timezone = maybe_or(json, "timezone", "local")
        network = maybe(json, "network")
        dns = maybe(json, "dns")
        ports = maybe(json, "ports")
        env = maybe(json, "env")
        secrets = maybe(json, "secrets")
        volumes = maybe(json, "volumes")
        capabilities = maybe(json, "capabilities")
        accounting = maybe(json, "accounting")
        self.name = str(name)
        self.image = Image.from_json(image, logger)
        self.privileged = privileged is not None and bool(privileged)
        self.read_only = read_only is not None and bool(read_only)
        self.replace = replace is not None and bool(replace)
        self.pull_policy = str(pull_policy)
        self.restart = str(restart)
        self.timezone = str(timezone)
        self.network = Network.from_json(network, logger)
        self.dns = Dns.from_json(dns, logger)
        self.ports = Ports.from_json(ports, logger)
        self.env = Environment.from_json(env, logger)
        self.env.file = "/var/lib/containerctl/containers/"
        self.env.file += f"{self.name}/environment"
        self.secrets = Secret.from_json(secrets, logger)
        self.volumes = Volume.from_json(volumes, logger)
        self.capabilities = Capability.from_json(capabilities, logger)
        self.accounting = Accounting.from_json(accounting, logger)

    def create_volumes(self) -> str:
        """Generate podman volume create commands."""
        if self.volumes is None:
            return ""
        volumes = ""
        for volume in self.volumes:
            volumes += volume.create()
        return volumes

    def create_secrets(self) -> str:
        """Generate podman secret create commands."""
        if self.secrets is None:
            return ""
        secrets = ""
        for secret in self.secrets:
            secrets += secret.create()
        return secrets

    def create_environment(self) -> str:
        """Wrap self.env.create()."""
        if self.env is None:
            return ""
        return self.env.create()

    def create_container(self) -> str:
        """Generate podman container create command."""
        cmd = f"# Create container {self.name}\n"
        cmd += "podman container crate \\\n"
        cmd += f"\t--name={self.name} \\\n"
        if self.privileged:
            cmd += "\t--privileged \\\n"
        if self.replace:
            cmd += "\t--replace \\\n"
        if self.read_only:
            cmd += "\t--read-only \\\n"
        cmd += f"\t--restart={self.restart} \\\n"
        cmd += f"\t--pull={self.pull_policy} \\\n"
        cmd += f"\t--tz={self.timezone} \\\n"
        cmd += f"\t{self.network.command()} \\\n"
        cmd += f"\t{self.dns.command()} \\\n"
        cmd += f"{self.ports.command()}"
        if self.env is not None:
            cmd += f"\t{self.env.command()} \\\n"
        for secret in self.secrets:
            cmd += f"\t{secret.command()} \\\n"
        for volume in self.volumes:
            cmd += f"\t{volume.command()} \\\n"
        for capability in self.capabilities:
            cmd += f"\t{capability.command()} \\\n"
        cmd += f"{self.accounting.command()}"
        cmd += f"\t{self.image.command()}\n"
        return cmd

    def start_container(self) -> str:
        """Generate podman container start command."""
        cmd = f"# Start container {self.name}\n"
        cmd += f"podman container start {self.name}\n"
        return cmd

    def stop_container(self) -> str:
        """Generate podman container stop command."""
        cmd = f"# Stop container {self.name}\n"
        cmd += f"podman container stop {self.name}\n"
        return cmd

    def restart_container(self) -> str:
        """Generate podman container restart composite command."""
        cmd = f"# Restart container {self.name}\n"
        cmd += self.stop_container()
        cmd += "sleep 5s\n"
        cmd += self.start_container()
        return cmd

    def upgrade_container(self) -> str:
        """Generate podman container upgrade composite command."""
        comment = f"# Upgrade container {self.name}\n"
        remove_container = self.remove_container()
        remove_env_file = self.remove_environment()
        create_container = self.create_container()
        create_env_file = self.create_environment()
        start_container = self.start_container()
        remove = f"{remove_container}\n{remove_env_file}\n"
        create = f"{create_env_file}\n{create_container}\n"
        create_and_start = create + "\n" + start_container
        return f"{comment}\n{remove}\n{create_and_start}"

    def purge_container(self) -> str:
        """Generate podman container purge composite command."""
        remove_container = self.remove_container()
        remove_volumes = self.remove_volumes()
        remove_secrets = self.remove_secrets()
        remove_env_file = self.remove_environment()
        remove_data = f"{remove_volumes}\n{remove_secrets}\n{remove_env_file}"
        return f"{remove_container}\n{remove_data}"

    def remove_container(self) -> str:
        """Generate podman container remove command."""
        cmd = self.stop_container()
        cmd += f"\n# Remove container {self.name}\n"
        cmd += f"podman container rm {self.name}\n"
        return cmd

    def remove_volumes(self) -> str:
        """Generate podman volume remove commands."""
        if self.volumes is None:
            return ""
        volumes = ""
        for volume in self.volumes:
            volumes += volume.remove()
        return volumes

    def remove_secrets(self) -> str:
        """Generate podman secret remove commands."""
        if self.secrets is None:
            return ""
        secrets = ""
        for secret in self.secrets:
            secrets += secret.remove()
        return secrets

    def remove_environment(self) -> str:
        """Wrap self.env.remove()."""
        if self.env is None:
            return ""
        return self.env.remove()