use std::str::FromStr;

use async_trait::async_trait;
use harmony_types::switch::{PortDeclaration, PortLocation};
use log::{debug, info};

use crate::{
    BrocadeClient, BrocadeInfo, Error, ExecutionMode, InterSwitchLink, InterfaceInfo,
    InterfaceStatus, InterfaceType, MacAddressEntry, PortChannelId, PortOperatingMode,
    parse_brocade_mac_address, shell::BrocadeShell,
};

pub struct NetworkOperatingSystemClient {
    shell: BrocadeShell,
    version: BrocadeInfo,
}

impl NetworkOperatingSystemClient {
    pub fn init(mut shell: BrocadeShell, version_info: BrocadeInfo) -> Self {
        shell.before_all(vec!["terminal length 0".into()]);

        Self {
            shell,
            version: version_info,
        }
    }

    fn parse_mac_entry(&self, line: &str) -> Option<Result<MacAddressEntry, Error>> {
        debug!("[Brocade] Parsing mac address entry: {line}");
        let parts: Vec<&str> = line.split_whitespace().collect();
        if parts.len() < 5 {
            return None;
        }

        let (vlan, mac_address, port) = match parts.len() {
            5 => (
                u16::from_str(parts[0]).ok()?,
                parse_brocade_mac_address(parts[1]).ok()?,
                parts[4].to_string(),
            ),
            _ => (
                u16::from_str(parts[0]).ok()?,
                parse_brocade_mac_address(parts[1]).ok()?,
                parts[5].to_string(),
            ),
        };

        let port =
            PortDeclaration::parse(&port).map_err(|e| Error::UnexpectedError(format!("{e}")));

        match port {
            Ok(p) => Some(Ok(MacAddressEntry {
                vlan,
                mac_address,
                port: p,
            })),
            Err(e) => Some(Err(e)),
        }
    }

    fn parse_inter_switch_link_entry(&self, line: &str) -> Option<Result<InterSwitchLink, Error>> {
        debug!("[Brocade] Parsing inter switch link entry: {line}");
        let parts: Vec<&str> = line.split_whitespace().collect();
        if parts.len() < 10 {
            return None;
        }

        let local_port = PortLocation::from_str(parts[2]).ok()?;
        let remote_port = PortLocation::from_str(parts[5]).ok()?;

        Some(Ok(InterSwitchLink {
            local_port,
            remote_port: Some(remote_port),
        }))
    }

    fn parse_interface_status_entry(&self, line: &str) -> Option<Result<InterfaceInfo, Error>> {
        debug!("[Brocade] Parsing interface status entry: {line}");
        let parts: Vec<&str> = line.split_whitespace().collect();
        if parts.len() < 6 {
            return None;
        }

        let interface_type = match parts[0] {
            "Fo" => InterfaceType::Ethernet("FortyGigabitEthernet".to_string()),
            "Te" => InterfaceType::Ethernet("TenGigabitEthernet".to_string()),
            _ => return None,
        };
        let port_location = PortLocation::from_str(parts[1]).ok()?;
        let status = match parts[2] {
            "connected" => InterfaceStatus::Connected,
            "notconnected" => InterfaceStatus::NotConnected,
            "sfpAbsent" => InterfaceStatus::SfpAbsent,
            _ => return None,
        };
        let operating_mode = match parts[3] {
            "ISL" => Some(PortOperatingMode::Fabric),
            "Trunk" => Some(PortOperatingMode::Trunk),
            "Access" => Some(PortOperatingMode::Access),
            "--" => None,
            _ => return None,
        };

        Some(Ok(InterfaceInfo {
            name: format!("{} {}", interface_type, port_location),
            port_location,
            interface_type,
            operating_mode,
            status,
        }))
    }
}

#[async_trait]
impl BrocadeClient for NetworkOperatingSystemClient {
    async fn version(&self) -> Result<BrocadeInfo, Error> {
        Ok(self.version.clone())
    }

    async fn get_mac_address_table(&self) -> Result<Vec<MacAddressEntry>, Error> {
        let output = self
            .shell
            .run_command("show mac-address-table", ExecutionMode::Regular)
            .await?;

        output
            .lines()
            .skip(1)
            .filter_map(|line| self.parse_mac_entry(line))
            .collect()
    }

    async fn get_stack_topology(&self) -> Result<Vec<InterSwitchLink>, Error> {
        let output = self
            .shell
            .run_command("show fabric isl", ExecutionMode::Regular)
            .await?;

        output
            .lines()
            .skip(6)
            .filter_map(|line| self.parse_inter_switch_link_entry(line))
            .collect()
    }

    async fn get_interfaces(&self) -> Result<Vec<InterfaceInfo>, Error> {
        let output = self
            .shell
            .run_command(
                "show interface status rbridge-id all",
                ExecutionMode::Regular,
            )
            .await?;

        output
            .lines()
            .skip(2)
            .filter_map(|line| self.parse_interface_status_entry(line))
            .collect()
    }

    async fn configure_interfaces(
        &self,
        interfaces: Vec<(String, PortOperatingMode)>,
    ) -> Result<(), Error> {
        info!("[Brocade] Configuring {} interface(s)...", interfaces.len());

        let mut commands = vec!["configure terminal".to_string()];

        for interface in interfaces {
            commands.push(format!("interface {}", interface.0));

            match interface.1 {
                PortOperatingMode::Fabric => {
                    commands.push("fabric isl enable".into());
                    commands.push("fabric trunk enable".into());
                }
                PortOperatingMode::Trunk => {
                    commands.push("switchport".into());
                    commands.push("switchport mode trunk".into());
                    commands.push("no spanning-tree shutdown".into());
                    commands.push("no fabric isl enable".into());
                    commands.push("no fabric trunk enable".into());
                }
                PortOperatingMode::Access => {
                    commands.push("switchport".into());
                    commands.push("switchport mode access".into());
                    commands.push("switchport access vlan 1".into());
                    commands.push("no spanning-tree shutdown".into());
                    commands.push("no fabric isl enable".into());
                    commands.push("no fabric trunk enable".into());
                }
            }

            commands.push("no shutdown".into());
            commands.push("exit".into());
        }

        commands.push("write memory".into());

        self.shell
            .run_commands(commands, ExecutionMode::Regular)
            .await?;

        info!("[Brocade] Interfaces configured.");

        Ok(())
    }

    async fn find_available_channel_id(&self) -> Result<PortChannelId, Error> {
        info!("[Brocade] Finding next available channel id...");

        let output = self
            .shell
            .run_command("show port-channel", ExecutionMode::Regular)
            .await?;

        let used_ids: Vec<u8> = output
            .lines()
            .skip(6)
            .filter_map(|line| {
                let parts: Vec<&str> = line.split_whitespace().collect();
                if parts.len() < 8 {
                    return None;
                }

                u8::from_str(parts[0]).ok()
            })
            .collect();

        let mut next_id: u8 = 1;
        loop {
            if !used_ids.contains(&next_id) {
                break;
            }
            next_id += 1;
        }

        info!("[Brocade] Found channel id: {next_id}");
        Ok(next_id)
    }

    async fn create_port_channel(
        &self,
        channel_id: PortChannelId,
        channel_name: &str,
        ports: &[PortLocation],
    ) -> Result<(), Error> {
        info!(
            "[Brocade] Configuring port-channel '{channel_name} {channel_id}' with ports: {ports:?}"
        );

        let interfaces = self.get_interfaces().await?;

        let mut commands = vec![
            "configure terminal".into(),
            format!("interface port-channel {}", channel_id),
            "no shutdown".into(),
            "exit".into(),
        ];

        for port in ports {
            let interface = interfaces.iter().find(|i| i.port_location == *port);
            let Some(interface) = interface else {
                continue;
            };

            commands.push(format!("interface {}", interface.name));
            commands.push("no switchport".into());
            commands.push("no ip address".into());
            commands.push("no fabric isl enable".into());
            commands.push("no fabric trunk enable".into());
            commands.push(format!("channel-group {} mode active", channel_id));
            commands.push("no shutdown".into());
            commands.push("exit".into());
        }

        commands.push("write memory".into());

        self.shell
            .run_commands(commands, ExecutionMode::Regular)
            .await?;

        info!("[Brocade] Port-channel '{channel_name}' configured.");

        Ok(())
    }

    async fn clear_port_channel(&self, channel_name: &str) -> Result<(), Error> {
        info!("[Brocade] Clearing port-channel: {channel_name}");

        let commands = vec![
            "configure terminal".into(),
            format!("no interface port-channel {}", channel_name),
            "exit".into(),
            "write memory".into(),
        ];

        self.shell
            .run_commands(commands, ExecutionMode::Regular)
            .await?;

        info!("[Brocade] Port-channel '{channel_name}' cleared.");
        Ok(())
    }
}