use std::process::{Command, Stdio};

use anyhow::{anyhow, Context, Result};
use log::info;
use sysinfo::{DiskExt, System, SystemExt};

use crate::impl_selectable_content;
use crate::mount_help::MountHelper;
use crate::password::{sudo, sudo_password, PasswordHolder, PasswordKind};
use crate::utils::current_username;

/// Possible actions on encrypted drives
#[derive(Debug, Clone, Copy)]
pub enum BlockDeviceAction {
    MOUNT,
    UMOUNT,
}

/// get devices list from lsblk
/// Return the output of
/// ```bash
/// lsblk -l -o FSTYPE,PATH,UUID,FSVER,MOUNTPOINT,PARTLABEL
/// ```
/// as a String.
fn get_devices() -> Result<String> {
    let output = Command::new("lsblk")
        .args(&vec!["-l", "-o", "FSTYPE,PATH,UUID,FSVER,MOUNTPOINT"])
        .stdin(Stdio::null())
        .stderr(Stdio::null())
        .output()?;
    Ok(String::from_utf8(output.stdout)?)
}

/// Parse the output of an lsblk detailed output and filter the line
/// Containing "crypto" aka Luks encrypted crypto devices
fn filter_crypto_devices_lines(output: String, key: &str) -> Vec<String> {
    output
        .lines()
        .filter(|line| line.contains(key))
        .map(|line| line.into())
        .collect()
}

/// Represent an encrypted device.
/// Those attributes comes from cryptsetup.
#[derive(Debug, Default, Clone)]
pub struct CryptoDevice {
    fs_type: String,
    path: String,
    uuid: String,
    fs_ver: String,
    mountpoints: Option<String>,
    device_name: Option<String>,
}

impl CryptoDevice {
    /// Parse the output of a lsblk formated line into a struct
    fn from_line(line: &str) -> Result<Self> {
        let mut crypo_device = Self::default();
        crypo_device.update_from_line(line)?;
        Ok(crypo_device)
    }

    fn update_from_line(&mut self, line: &str) -> Result<()> {
        let strings = line.split_whitespace();
        let mut params: Vec<Option<String>> = vec![None; 5];
        for (count, param) in strings.enumerate() {
            params[count] = Some(param.to_owned());
        }
        self.fs_type = params
            .remove(0)
            .context("CryptoDevice: parameter shouldn't be None")?;
        self.path = params
            .remove(0)
            .context("CryptoDevice: parameter shouldn't be None")?;
        self.uuid = params
            .remove(0)
            .context("CryptoDevice: parameter shouldn't be None")?;
        self.fs_ver = params
            .remove(0)
            .context("CryptoDevice: parameter shouldn't be None")?;
        self.mountpoints = params.remove(0);
        Ok(())
    }

    fn format_luksopen_parameters(&self) -> [String; 4] {
        [
            "cryptsetup".to_owned(),
            "open".to_owned(),
            self.path.clone(),
            self.uuid.clone(),
        ]
    }
    fn format_luksclose_parameters(&self) -> [String; 3] {
        [
            "cryptsetup".to_owned(),
            "luksClose".to_owned(),
            self.device_name
                .clone()
                .unwrap_or_else(|| self.uuid.clone()),
        ]
    }

    pub fn mount_point(&self) -> Option<String> {
        let system_info = System::new_all();
        system_info
            .disks()
            .iter()
            .map(|d| d.mount_point())
            .map(|p| p.to_str())
            .filter(|s| s.is_some())
            .map(|s| s.unwrap().to_owned())
            .find(|s| s.contains(&self.uuid))
    }

    fn set_device_name(&mut self) -> Result<()> {
        let child = Command::new("lsblk")
            .arg("-l")
            .arg("-n")
            .arg(self.path.clone())
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .stderr(Stdio::piped())
            .spawn()?;
        let output = child.wait_with_output()?;
        info!(
            "is opened ? output of lsblk\nstdout: {}\nstderr{}",
            String::from_utf8(output.stdout.clone())?,
            String::from_utf8(output.stderr)?
        );
        let output = String::from_utf8(output.stdout)?;
        if let Some(s) = output.lines().nth(1) {
            self.device_name = Some(
                s.split_whitespace()
                    .next()
                    .context("mapped point: shouldn't be empty")?
                    .to_owned(),
            );
        } else {
            self.device_name = None;
        }
        Ok(())
    }

    fn open_mount(&mut self, username: &str, password: &mut PasswordHolder) -> Result<bool> {
        self.set_device_name()?;
        if self.is_mounted() {
            Err(anyhow!("luks open mount: device is already mounted"))
        } else {
            // sudo
            let (success, _, _) = sudo_password(
                &["-S".to_owned(), "ls".to_owned(), "/root".to_owned()],
                &password.sudo()?,
            )?;
            if !success {
                return Ok(false);
            }
            // open
            let (success, stdout, stderr) =
                sudo_password(&self.format_luksopen_parameters(), &password.cryptsetup()?)?;
            info!("stdout: {}\nstderr: {}", stdout, stderr);
            if !success {
                return Ok(false);
            }
            self.mount(username, password)
        }
    }

    fn umount_close(&mut self, username: &str, password: &mut PasswordHolder) -> Result<bool> {
        if !self.umount(username, password)? {
            return Ok(false);
        }
        // close
        let (success, stdout, stderr) = sudo(&self.format_luksclose_parameters())?;
        info!("stdout: {}\nstderr: {}", stdout, stderr);
        if !success {
            return Ok(false);
        }
        // sudo -k
        let (success, stdout, stderr) = sudo(&["-k".to_owned()])?;
        info!("stdout: {}\nstderr: {}", stdout, stderr);
        Ok(success)
    }
}

impl MountHelper for CryptoDevice {
    fn format_mkdir_parameters(&self, username: &str) -> [String; 3] {
        [
            "mkdir".to_owned(),
            "-p".to_owned(),
            format!(
                "/run/media/{}/{}",
                username,
                self.device_name
                    .clone()
                    .unwrap_or_else(|| self.uuid.clone())
            ),
        ]
    }

    fn format_mount_parameters(&mut self, username: &str) -> Vec<String> {
        vec![
            "mount".to_owned(),
            format!("/dev/mapper/{}", self.uuid),
            format!(
                "/run/media/{}/{}",
                username,
                self.device_name
                    .clone()
                    .unwrap_or_else(|| self.uuid.clone())
            ),
        ]
    }

    fn format_umount_parameters(&self, username: &str) -> Vec<String> {
        vec![
            "umount".to_owned(),
            format!(
                "/run/media/{}/{}",
                username,
                self.device_name
                    .clone()
                    .unwrap_or_else(|| self.uuid.clone())
            ),
        ]
    }

    /// True if there's a mount point for this drive.
    /// It's only valid if we mounted the device since it requires
    /// the uuid to be in the mount point.
    fn is_mounted(&self) -> bool {
        self.mount_point().is_some()
    }

    fn mount(&mut self, username: &str, _: &mut PasswordHolder) -> Result<bool> {
        self.set_device_name()?;
        // mkdir
        let (success, stdout, stderr) = sudo(&self.format_mkdir_parameters(username))?;
        info!("stdout: {}\nstderr: {}", stdout, stderr);
        if !success {
            return Ok(false);
        }
        // mount
        let (success, stdout, stderr) = sudo(&self.format_mount_parameters(username))?;
        info!("stdout: {}\nstderr: {}", stdout, stderr);
        if !success {
            return Ok(false);
        }
        // sudo -k
        sudo(&["-k".to_owned()])?;
        Ok(success)
    }

    fn umount(&mut self, username: &str, password: &mut PasswordHolder) -> Result<bool> {
        self.set_device_name()?;
        // sudo
        let (success, _, _) = sudo_password(
            &["-S".to_owned(), "ls".to_owned(), "/root".to_owned()],
            &password.sudo()?,
        )?;
        if !success {
            return Ok(false);
        }
        // unmount
        let (_, stdout, stderr) = sudo(&self.format_umount_parameters(username))?;
        info!("stdout: {}\nstderr: {}", stdout, stderr);

        Ok(true)
    }

    /// String representation of the device.
    fn as_string(&self) -> Result<String> {
        Ok(if let Some(mount_point) = self.mount_point() {
            format!("{} -> {}", self.path, mount_point)
        } else {
            format!("{} - not mounted", self.path)
        })
    }
}

/// Holds the device itself and its passwords.
#[derive(Debug, Clone, Default)]
pub struct CryptoDeviceMounter {
    pub cryptdevice: CryptoDevice,
    pub password_holder: PasswordHolder,
}

impl CryptoDeviceMounter {
    /// Reads a device from  a line of text from cryptsetup.
    pub fn from_line(line: &str) -> Result<Self> {
        Ok(Self {
            cryptdevice: CryptoDevice::from_line(line)?,
            password_holder: PasswordHolder::default(),
        })
    }
}

/// Holds a list of devices and an index.
/// It's a navigable content so the index follows the selection
/// of the user.
#[derive(Debug, Clone, Default)]
pub struct CryptoDeviceOpener {
    pub content: Vec<CryptoDeviceMounter>,
    index: usize,
}

impl CryptoDeviceOpener {
    /// Updates itself from the output of cryptsetup.
    pub fn update(&mut self) -> Result<()> {
        self.content = filter_crypto_devices_lines(get_devices()?, "crypto")
            .iter()
            .map(|line| CryptoDeviceMounter::from_line(line))
            .filter_map(|r| r.ok())
            .collect();
        self.index = 0;
        Ok(())
    }

    /// Set a password for the selected device.
    pub fn set_password(&mut self, password_kind: PasswordKind, password: String) {
        match password_kind {
            PasswordKind::SUDO => self.content[self.index].password_holder.set_sudo(password),
            PasswordKind::CRYPTSETUP => self.content[self.index]
                .password_holder
                .set_cryptsetup(password),
        }
    }

    /// Open and mount the selected device.
    pub fn mount_selected(&mut self) -> Result<()> {
        let username = current_username()?;
        let mut passwords = self.content[self.index].password_holder.clone();
        let success = self.content[self.index]
            .cryptdevice
            .open_mount(&username, &mut passwords)?;
        if !success {
            Self::reset_faillock()?
        }
        self.content[self.index].password_holder.reset();
        Self::drop_sudo()?;
        Ok(())
    }

    /// Unmount and close the selected device.
    pub fn umount_selected(&mut self) -> Result<()> {
        let username = current_username()?;
        let mut passwords = self.content[self.index].password_holder.clone();
        let success = self.content[self.index]
            .cryptdevice
            .umount_close(&username, &mut passwords)?;
        if !success {
            Self::reset_faillock()?
        }
        self.content[self.index].password_holder.reset();
        Self::drop_sudo()?;
        Ok(())
    }

    fn reset_faillock() -> Result<()> {
        Command::new("faillock")
            .arg("--user")
            .arg(current_username()?)
            .arg("--reset")
            .stdin(Stdio::null())
            .stdout(Stdio::null())
            .stderr(Stdio::null())
            .spawn()?;
        Ok(())
    }

    fn drop_sudo() -> Result<()> {
        Command::new("sudo")
            .arg("-k")
            .stdin(Stdio::null())
            .stdout(Stdio::null())
            .stderr(Stdio::null())
            .spawn()?;
        Ok(())
    }

    /// True if the selected device has sudo password.
    pub fn has_sudo(&self) -> bool {
        self.content[self.index].password_holder.has_sudo()
    }

    /// True if the selected device has cryptsetup passphrase.
    pub fn has_cryptsetup(&self) -> bool {
        self.content[self.index].password_holder.has_cryptsetup()
    }
}

impl_selectable_content!(CryptoDeviceMounter, CryptoDeviceOpener);