use crate::input::actions::Action;
use crate::input::config::ConversionError;
use clap::ArgEnum;
use serde::{Deserialize, Serialize};
use std::fmt;
use std::str::FromStr;
use strum_macros::{EnumDiscriminants, EnumIter, EnumString, ToString};

pub type ClientId = u16; // TODO: merge with crate type?

pub fn client_id_to_colors(
    client_id: ClientId,
    colors: Palette,
) -> Option<(PaletteColor, PaletteColor)> {
    // (primary color, secondary color)
    match client_id {
        1 => Some((colors.magenta, colors.black)),
        2 => Some((colors.blue, colors.black)),
        3 => Some((colors.purple, colors.black)),
        4 => Some((colors.yellow, colors.black)),
        5 => Some((colors.cyan, colors.black)),
        6 => Some((colors.gold, colors.black)),
        7 => Some((colors.red, colors.black)),
        8 => Some((colors.silver, colors.black)),
        9 => Some((colors.pink, colors.black)),
        10 => Some((colors.brown, colors.black)),
        _ => None,
    }
}

pub fn single_client_color(colors: Palette) -> (PaletteColor, PaletteColor) {
    (colors.green, colors.black)
}

// TODO: Add a shortened string representation (beyond `Display::fmt` below) that can be used when
// screen space is scarce. Useful for e.g. "ENTER", "SPACE", "TAB" to display as Unicode
// representations instead.
// NOTE: Do not reorder the key variants since that influences what the `status_bar` plugin
// displays!
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, PartialOrd, Ord)]
pub enum Key {
    PageDown,
    PageUp,
    Left,
    Down,
    Up,
    Right,
    Home,
    End,
    Backspace,
    Delete,
    Insert,
    F(u8),
    Char(char),
    Alt(CharOrArrow),
    Ctrl(char),
    BackTab,
    Null,
    Esc,
}

impl FromStr for Key {
    type Err = Box<dyn std::error::Error>;
    fn from_str(key_str: &str) -> Result<Self, Self::Err> {
        let mut modifier: Option<&str> = None;
        let mut main_key: Option<&str> = None;
        for (index, part) in key_str.split_ascii_whitespace().enumerate() {
            if index == 0 && (part == "Ctrl" || part == "Alt") {
                modifier = Some(part);
            } else if main_key.is_none() {
                main_key = Some(part)
            }
        }
        match (modifier, main_key) {
            (Some("Ctrl"), Some(main_key)) => {
                let mut key_chars = main_key.chars();
                let key_count = main_key.chars().count();
                if key_count == 1 {
                    let key_char = key_chars.next().unwrap();
                    Ok(Key::Ctrl(key_char))
                } else {
                    Err(format!("Failed to parse key: {}", key_str).into())
                }
            },
            (Some("Alt"), Some(main_key)) => {
                match main_key {
                    // why crate::data::Direction and not just Direction?
                    // Because it's a different type that we export in this wasm mandated soup - we
                    // don't like it either! This will be solved as we chip away at our tech-debt
                    "Left" => Ok(Key::Alt(CharOrArrow::Direction(Direction::Left))),
                    "Right" => Ok(Key::Alt(CharOrArrow::Direction(Direction::Right))),
                    "Up" => Ok(Key::Alt(CharOrArrow::Direction(Direction::Up))),
                    "Down" => Ok(Key::Alt(CharOrArrow::Direction(Direction::Down))),
                    _ => {
                        let mut key_chars = main_key.chars();
                        let key_count = main_key.chars().count();
                        if key_count == 1 {
                            let key_char = key_chars.next().unwrap();
                            Ok(Key::Alt(CharOrArrow::Char(key_char)))
                        } else {
                            Err(format!("Failed to parse key: {}", key_str).into())
                        }
                    },
                }
            },
            (None, Some(main_key)) => match main_key {
                "Backspace" => Ok(Key::Backspace),
                "Left" => Ok(Key::Left),
                "Right" => Ok(Key::Right),
                "Up" => Ok(Key::Up),
                "Down" => Ok(Key::Down),
                "Home" => Ok(Key::Home),
                "End" => Ok(Key::End),
                "PageUp" => Ok(Key::PageUp),
                "PageDown" => Ok(Key::PageDown),
                "Tab" => Ok(Key::BackTab),
                "Delete" => Ok(Key::Delete),
                "Insert" => Ok(Key::Insert),
                "Space" => Ok(Key::Char(' ')),
                "Enter" => Ok(Key::Char('\n')),
                "Esc" => Ok(Key::Esc),
                _ => {
                    let mut key_chars = main_key.chars();
                    let key_count = main_key.chars().count();
                    if key_count == 1 {
                        let key_char = key_chars.next().unwrap();
                        Ok(Key::Char(key_char))
                    } else if key_count > 1 {
                        if let Some(first_char) = key_chars.next() {
                            if first_char == 'F' {
                                let f_index: String = key_chars.collect();
                                let f_index: u8 = f_index
                                    .parse()
                                    .map_err(|e| format!("Failed to parse F index: {}", e))?;
                                if f_index >= 1 && f_index <= 12 {
                                    return Ok(Key::F(f_index));
                                }
                            }
                        }
                        Err(format!("Failed to parse key: {}", key_str).into())
                    } else {
                        Err(format!("Failed to parse key: {}", key_str).into())
                    }
                },
            },
            _ => Err(format!("Failed to parse key: {}", key_str).into()),
        }
    }
}

impl fmt::Display for Key {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Key::Backspace => write!(f, "BACKSPACE"),
            Key::Left => write!(f, "{}", Direction::Left),
            Key::Right => write!(f, "{}", Direction::Right),
            Key::Up => write!(f, "{}", Direction::Up),
            Key::Down => write!(f, "{}", Direction::Down),
            Key::Home => write!(f, "HOME"),
            Key::End => write!(f, "END"),
            Key::PageUp => write!(f, "PgUp"),
            Key::PageDown => write!(f, "PgDn"),
            Key::BackTab => write!(f, "TAB"),
            Key::Delete => write!(f, "DEL"),
            Key::Insert => write!(f, "INS"),
            Key::F(n) => write!(f, "F{}", n),
            Key::Char(c) => match c {
                '\n' => write!(f, "ENTER"),
                '\t' => write!(f, "TAB"),
                ' ' => write!(f, "SPACE"),
                _ => write!(f, "{}", c),
            },
            Key::Alt(c) => write!(f, "Alt+{}", c),
            Key::Ctrl(c) => write!(f, "Ctrl+{}", Key::Char(*c)),
            Key::Null => write!(f, "NULL"),
            Key::Esc => write!(f, "ESC"),
        }
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, PartialOrd, Ord)]
#[serde(untagged)]
pub enum CharOrArrow {
    Char(char),
    Direction(Direction),
}

impl fmt::Display for CharOrArrow {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            CharOrArrow::Char(c) => write!(f, "{}", Key::Char(*c)),
            CharOrArrow::Direction(d) => write!(f, "{}", d),
        }
    }
}

/// The four directions (left, right, up, down).
#[derive(Eq, Clone, Copy, Debug, PartialEq, Hash, Deserialize, Serialize, PartialOrd, Ord)]
pub enum Direction {
    Left,
    Right,
    Up,
    Down,
}

impl Direction {
    pub fn invert(&self) -> Direction {
        match *self {
            Direction::Left => Direction::Right,
            Direction::Down => Direction::Up,
            Direction::Up => Direction::Down,
            Direction::Right => Direction::Left,
        }
    }

    pub fn is_horizontal(&self) -> bool {
        matches!(self, Direction::Left | Direction::Right)
    }

    pub fn is_vertical(&self) -> bool {
        matches!(self, Direction::Down | Direction::Up)
    }
}

impl fmt::Display for Direction {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Direction::Left => write!(f, "←"),
            Direction::Right => write!(f, "→"),
            Direction::Up => write!(f, "↑"),
            Direction::Down => write!(f, "↓"),
        }
    }
}

impl FromStr for Direction {
    type Err = String;
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            "Left" | "left" => Ok(Direction::Left),
            "Right" | "right" => Ok(Direction::Right),
            "Up" | "up" => Ok(Direction::Up),
            "Down" | "down" => Ok(Direction::Down),
            _ => Err(format!(
                "Failed to parse Direction. Unknown Direction: {}",
                s
            )),
        }
    }
}

/// Resize operation to perform.
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash, Deserialize, Serialize)]
pub enum Resize {
    Increase,
    Decrease,
}

impl Resize {
    pub fn invert(&self) -> Self {
        match self {
            Resize::Increase => Resize::Decrease,
            Resize::Decrease => Resize::Increase,
        }
    }
}

impl fmt::Display for Resize {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Resize::Increase => write!(f, "+"),
            Resize::Decrease => write!(f, "-"),
        }
    }
}

impl FromStr for Resize {
    type Err = String;
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            "Increase" | "increase" | "+" => Ok(Resize::Increase),
            "Decrease" | "decrease" | "-" => Ok(Resize::Decrease),
            _ => Err(format!(
                "failed to parse resize type. Unknown specifier '{}'",
                s
            )),
        }
    }
}

/// Container type that fully describes resize operations.
///
/// This is best thought of as follows:
///
/// - `resize` commands how the total *area* of the pane will change as part of this resize
///   operation.
/// - `direction` has two meanings:
///     - `None` means to resize all borders equally
///     - Anything else means to move the named border to achieve the change in area
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash, Deserialize, Serialize)]
pub struct ResizeStrategy {
    /// Whether to increase or resize total area
    pub resize: Resize,
    /// With which border, if any, to change area
    pub direction: Option<Direction>,
    /// If set to true (default), increasing resizes towards a viewport border will be inverted.
    /// I.e. a scenario like this ("increase right"):
    ///
    /// ```text
    /// +---+---+
    /// |   | X |->
    /// +---+---+
    /// ```
    ///
    /// turns into this ("decrease left"):
    ///
    /// ```text
    /// +---+---+
    /// |   |-> |
    /// +---+---+
    /// ```
    pub invert_on_boundaries: bool,
}

impl From<Direction> for ResizeStrategy {
    fn from(direction: Direction) -> Self {
        ResizeStrategy::new(Resize::Increase, Some(direction))
    }
}

impl From<Resize> for ResizeStrategy {
    fn from(resize: Resize) -> Self {
        ResizeStrategy::new(resize, None)
    }
}

impl ResizeStrategy {
    pub fn new(resize: Resize, direction: Option<Direction>) -> Self {
        ResizeStrategy {
            resize,
            direction,
            invert_on_boundaries: true,
        }
    }

    pub fn invert(&self) -> ResizeStrategy {
        let resize = match self.resize {
            Resize::Increase => Resize::Decrease,
            Resize::Decrease => Resize::Increase,
        };
        let direction = match self.direction {
            Some(direction) => Some(direction.invert()),
            None => None,
        };

        ResizeStrategy::new(resize, direction)
    }

    pub fn resize_type(&self) -> Resize {
        self.resize
    }

    pub fn direction(&self) -> Option<Direction> {
        self.direction
    }

    pub fn direction_horizontal(&self) -> bool {
        matches!(
            self.direction,
            Some(Direction::Left) | Some(Direction::Right)
        )
    }

    pub fn direction_vertical(&self) -> bool {
        matches!(self.direction, Some(Direction::Up) | Some(Direction::Down))
    }

    pub fn resize_increase(&self) -> bool {
        self.resize == Resize::Increase
    }

    pub fn resize_decrease(&self) -> bool {
        self.resize == Resize::Decrease
    }

    pub fn move_left_border_left(&self) -> bool {
        (self.resize == Resize::Increase) && (self.direction == Some(Direction::Left))
    }

    pub fn move_left_border_right(&self) -> bool {
        (self.resize == Resize::Decrease) && (self.direction == Some(Direction::Left))
    }

    pub fn move_lower_border_down(&self) -> bool {
        (self.resize == Resize::Increase) && (self.direction == Some(Direction::Down))
    }

    pub fn move_lower_border_up(&self) -> bool {
        (self.resize == Resize::Decrease) && (self.direction == Some(Direction::Down))
    }

    pub fn move_upper_border_up(&self) -> bool {
        (self.resize == Resize::Increase) && (self.direction == Some(Direction::Up))
    }

    pub fn move_upper_border_down(&self) -> bool {
        (self.resize == Resize::Decrease) && (self.direction == Some(Direction::Up))
    }

    pub fn move_right_border_right(&self) -> bool {
        (self.resize == Resize::Increase) && (self.direction == Some(Direction::Right))
    }

    pub fn move_right_border_left(&self) -> bool {
        (self.resize == Resize::Decrease) && (self.direction == Some(Direction::Right))
    }

    pub fn move_all_borders_out(&self) -> bool {
        (self.resize == Resize::Increase) && (self.direction == None)
    }

    pub fn move_all_borders_in(&self) -> bool {
        (self.resize == Resize::Decrease) && (self.direction == None)
    }
}

impl fmt::Display for ResizeStrategy {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let resize = match self.resize {
            Resize::Increase => "increase",
            Resize::Decrease => "decrease",
        };
        let border = match self.direction {
            Some(Direction::Left) => "left",
            Some(Direction::Down) => "bottom",
            Some(Direction::Up) => "top",
            Some(Direction::Right) => "right",
            None => "every",
        };

        write!(f, "{} size on {} border", resize, border)
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
// FIXME: This should be extended to handle different button clicks (not just
// left click) and the `ScrollUp` and `ScrollDown` events could probably be
// merged into a single `Scroll(isize)` event.
pub enum Mouse {
    ScrollUp(usize),          // number of lines
    ScrollDown(usize),        // number of lines
    LeftClick(isize, usize),  // line and column
    RightClick(isize, usize), // line and column
    Hold(isize, usize),       // line and column
    Release(isize, usize),    // line and column
}

#[derive(Debug, Clone, PartialEq, EnumDiscriminants, ToString, Serialize, Deserialize)]
#[strum_discriminants(derive(EnumString, Hash, Serialize, Deserialize))]
#[strum_discriminants(name(EventType))]
#[non_exhaustive]
pub enum Event {
    ModeUpdate(ModeInfo),
    TabUpdate(Vec<TabInfo>),
    Key(Key),
    Mouse(Mouse),
    Timer(f64),
    CopyToClipboard(CopyDestination),
    SystemClipboardFailure,
    InputReceived,
    Visible(bool),
}

/// Describes the different input modes, which change the way that keystrokes will be interpreted.
#[derive(
    Debug,
    PartialEq,
    Eq,
    Hash,
    Copy,
    Clone,
    EnumIter,
    Serialize,
    Deserialize,
    ArgEnum,
    PartialOrd,
    Ord,
)]
pub enum InputMode {
    /// In `Normal` mode, input is always written to the terminal, except for the shortcuts leading
    /// to other modes
    #[serde(alias = "normal")]
    Normal,
    /// In `Locked` mode, input is always written to the terminal and all shortcuts are disabled
    /// except the one leading back to normal mode
    #[serde(alias = "locked")]
    Locked,
    /// `Resize` mode allows resizing the different existing panes.
    #[serde(alias = "resize")]
    Resize,
    /// `Pane` mode allows creating and closing panes, as well as moving between them.
    #[serde(alias = "pane")]
    Pane,
    /// `Tab` mode allows creating and closing tabs, as well as moving between them.
    #[serde(alias = "tab")]
    Tab,
    /// `Scroll` mode allows scrolling up and down within a pane.
    #[serde(alias = "scroll")]
    Scroll,
    /// `EnterSearch` mode allows for typing in the needle for a search in the scroll buffer of a pane.
    #[serde(alias = "entersearch")]
    EnterSearch,
    /// `Search` mode allows for searching a term in a pane (superset of `Scroll`).
    #[serde(alias = "search")]
    Search,
    /// `RenameTab` mode allows assigning a new name to a tab.
    #[serde(alias = "renametab")]
    RenameTab,
    /// `RenamePane` mode allows assigning a new name to a pane.
    #[serde(alias = "renamepane")]
    RenamePane,
    /// `Session` mode allows detaching sessions
    #[serde(alias = "session")]
    Session,
    /// `Move` mode allows moving the different existing panes within a tab
    #[serde(alias = "move")]
    Move,
    /// `Prompt` mode allows interacting with active prompts.
    #[serde(alias = "prompt")]
    Prompt,
    /// `Tmux` mode allows for basic tmux keybindings functionality
    #[serde(alias = "tmux")]
    Tmux,
}

// impl TryFrom<&str> for InputMode {
//     type Error = String;
//     fn try_from(mode: &str) -> Result<Self, String> {
//         match mode {
//             "normal" | "Normal" => Ok(InputMode::Normal),
//             "locked" | "Locked" => Ok(InputMode::Locked),
//             "resize" | "Resize" => Ok(InputMode::Resize),
//             "pane" | "Pane" => Ok(InputMode::Pane),
//             "tab" | "Tab" => Ok(InputMode::Tab),
//             "search" | "Search" => Ok(InputMode::Search),
//             "renametab" | "RenameTab" => Ok(InputMode::RenameTab),
//             "renamepane" | "RenamePane" => Ok(InputMode::RenamePane),
//             "session" | "Session" => Ok(InputMode::Session),
//             "move" | "Move" => Ok(InputMode::Move),
//             "prompt" | "Prompt" => Ok(InputMode::Prompt),
//             "tmux" | "Tmux" => Ok(InputMode::Tmux),
//             _ => Err(format!("Unrecognized mode: {}", mode)),
//         }
//     }
// }

impl Default for InputMode {
    fn default() -> InputMode {
        InputMode::Normal
    }
}

#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum ThemeHue {
    Light,
    Dark,
}
impl Default for ThemeHue {
    fn default() -> ThemeHue {
        ThemeHue::Dark
    }
}

#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum PaletteColor {
    Rgb((u8, u8, u8)),
    EightBit(u8),
}
impl Default for PaletteColor {
    fn default() -> PaletteColor {
        PaletteColor::EightBit(0)
    }
}

impl FromStr for InputMode {
    type Err = ConversionError;

    fn from_str(s: &str) -> Result<Self, ConversionError> {
        match s {
            "normal" | "Normal" => Ok(InputMode::Normal),
            "locked" | "Locked" => Ok(InputMode::Locked),
            "resize" | "Resize" => Ok(InputMode::Resize),
            "pane" | "Pane" => Ok(InputMode::Pane),
            "tab" | "Tab" => Ok(InputMode::Tab),
            "search" | "Search" => Ok(InputMode::Search),
            "scroll" | "Scroll" => Ok(InputMode::Scroll),
            "renametab" | "RenameTab" => Ok(InputMode::RenameTab),
            "renamepane" | "RenamePane" => Ok(InputMode::RenamePane),
            "session" | "Session" => Ok(InputMode::Session),
            "move" | "Move" => Ok(InputMode::Move),
            "prompt" | "Prompt" => Ok(InputMode::Prompt),
            "tmux" | "Tmux" => Ok(InputMode::Tmux),
            "entersearch" | "Entersearch" | "EnterSearch" => Ok(InputMode::EnterSearch),
            e => Err(ConversionError::UnknownInputMode(e.into())),
        }
    }
}

#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum PaletteSource {
    Default,
    Xresources,
}
impl Default for PaletteSource {
    fn default() -> PaletteSource {
        PaletteSource::Default
    }
}
#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, Hash, Default)]
pub struct Palette {
    pub source: PaletteSource,
    pub theme_hue: ThemeHue,
    pub fg: PaletteColor,
    pub bg: PaletteColor,
    pub black: PaletteColor,
    pub red: PaletteColor,
    pub green: PaletteColor,
    pub yellow: PaletteColor,
    pub blue: PaletteColor,
    pub magenta: PaletteColor,
    pub cyan: PaletteColor,
    pub white: PaletteColor,
    pub orange: PaletteColor,
    pub gray: PaletteColor,
    pub purple: PaletteColor,
    pub gold: PaletteColor,
    pub silver: PaletteColor,
    pub pink: PaletteColor,
    pub brown: PaletteColor,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Default, Serialize, Deserialize)]
pub struct Style {
    pub colors: Palette,
    pub rounded_corners: bool,
}

// FIXME: Poor devs hashtable since HashTable can't derive `Default`...
pub type KeybindsVec = Vec<(InputMode, Vec<(Key, Vec<Action>)>)>;

/// Represents the contents of the help message that is printed in the status bar,
/// which indicates the current [`InputMode`] and what the keybinds for that mode
/// are. Related to the default `status-bar` plugin.
#[derive(Default, Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct ModeInfo {
    pub mode: InputMode,
    pub keybinds: KeybindsVec,
    pub style: Style,
    pub capabilities: PluginCapabilities,
    pub session_name: Option<String>,
}

impl ModeInfo {
    pub fn get_mode_keybinds(&self) -> Vec<(Key, Vec<Action>)> {
        self.get_keybinds_for_mode(self.mode)
    }

    pub fn get_keybinds_for_mode(&self, mode: InputMode) -> Vec<(Key, Vec<Action>)> {
        for (vec_mode, map) in &self.keybinds {
            if mode == *vec_mode {
                return map.to_vec();
            }
        }
        vec![]
    }
}

#[derive(Debug, Default, Clone, PartialEq, Eq, Hash, Deserialize, Serialize)]
pub struct TabInfo {
    /* subset of fields to publish to plugins */
    pub position: usize,
    pub name: String,
    pub active: bool,
    pub panes_to_hide: usize,
    pub is_fullscreen_active: bool,
    pub is_sync_panes_active: bool,
    pub are_floating_panes_visible: bool,
    pub other_focused_clients: Vec<ClientId>,
}

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Deserialize, Serialize)]
pub struct PluginIds {
    pub plugin_id: u32,
    pub zellij_pid: u32,
}

/// Tag used to identify the plugin in layout and config yaml files
#[derive(Debug, Default, Clone, PartialEq, Eq, Hash, Deserialize, Serialize, PartialOrd, Ord)]
pub struct PluginTag(String);

impl PluginTag {
    pub fn new(url: impl Into<String>) -> Self {
        PluginTag(url.into())
    }
}

impl From<PluginTag> for String {
    fn from(tag: PluginTag) -> Self {
        tag.0
    }
}

impl fmt::Display for PluginTag {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.0)
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Deserialize, Serialize)]
pub struct PluginCapabilities {
    pub arrow_fonts: bool,
}

impl Default for PluginCapabilities {
    fn default() -> PluginCapabilities {
        PluginCapabilities { arrow_fonts: true }
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Serialize, Deserialize)]
pub enum CopyDestination {
    Command,
    Primary,
    System,
}