use std::fs::File;
use std::path::PathBuf;
use std::io::{Write, BufRead, BufReader};

use subxt::ext::sp_core::crypto::{AccountId32, Ss58AddressFormat, Ss58Codec};

use color_eyre::Result;
use crossterm::event::{KeyCode, KeyEvent};
use ratatui::layout::{Constraint, Margin};
use ratatui::style::{Stylize, Modifier};
use ratatui::widgets::Clear;
use ratatui::{
    text::{Line, Text},
    layout::{Alignment, Rect}, 
    widgets::{
        Block, Cell, Row, Table, TableState, Scrollbar, Padding,
        ScrollbarOrientation, ScrollbarState,
    }, 
    Frame
};
use tokio::sync::mpsc::UnboundedSender;
use std::sync::mpsc::Sender;

use super::{PartialComponent, Component, CurrentTab};
use crate::types::{ActionLevel, Nominations, ActionTarget, EraRewardPoints};
use crate::{
    action::Action, 
    config::Config, 
    palette::StylePalette, 
};

pub struct CurrentValidators {
    is_active: bool,
    network_tx: Option<Sender<Action>>,
    action_tx: Option<UnboundedSender<Action>>,
    known_validators_file: PathBuf,
    palette: StylePalette,
    scroll_state: ScrollbarState,
    table_state: TableState,
    individual: Vec<EraRewardPoints>,
    not_active_nominations: Vec<EraRewardPoints>,
    known_validators: std::collections::HashMap<[u8; 32], String>,
    checked_validators: std::collections::HashSet<[u8; 32]>,
    total_points: u32,
    era_index: u32,
    my_stash_id: Option<[u8; 32]>,
    account_id: [u8; 32],
    account_secret_seed: [u8; 32],
    my_nominations: std::collections::HashMap<[u8; 32], Nominations>,
    filtered_vector: Vec<EraRewardPoints>,
}

impl Default for CurrentValidators {
    fn default() -> Self {
        Self::new()
    }
}

impl CurrentValidators {
    const KNOWN_VALIDATORS_FILE: &str = "known-validators";

    pub fn new() -> Self {
        Self {
            is_active: false,
            network_tx: None,
            action_tx: None,
            known_validators_file: Default::default(),
            scroll_state: ScrollbarState::new(0),
            table_state: TableState::new(),
            individual: Default::default(),
            known_validators: Default::default(),
            checked_validators: Default::default(),
            total_points: 0,
            era_index: 0,
            my_stash_id: None,
            account_id: [0u8; 32],
            account_secret_seed: [0u8; 32],
            palette: StylePalette::default(),
            my_nominations: Default::default(),
            not_active_nominations: Default::default(),
            filtered_vector: Default::default(),
        }
    }

    fn close_popup(&mut self) {
        self.is_active = false;
        if let Some(action_tx) = &self.action_tx {
            let _ = action_tx.send(Action::ClosePopup);
        }
    }

    fn move_selected(&mut self, index: usize) {
        if self.filtered_vector.len() > 0 {
            self.table_state.select(Some(index));
            self.scroll_state = self.scroll_state.position(index);
            self.update_choosen_details(index);
        }
    }

    fn update_used_account(&mut self, account_id: [u8; 32], secret_seed_str: String) {
        let secret_seed: [u8; 32] = hex::decode(secret_seed_str)
            .expect("stored seed is valid hex string; qed")
            .as_slice()
            .try_into()
            .expect("stored seed is valid length; qed");
        self.account_id = account_id;
        self.account_secret_seed = secret_seed;
    }

    fn store_nominators(&mut self, nominations: Nominations, account_id: [u8; 32]) {
        if self.account_id == account_id {
            self.not_active_nominations.clear();
            for account in nominations.targets.iter() {
                if !self.individual.iter().any(|r| r.account_id == *account) {
                    self.not_active_nominations.push(EraRewardPoints {
                        account_id: *account,
                        address: AccountId32::from(*account)
                            .to_ss58check_with_version(Ss58AddressFormat::custom(1996)),
                            points: 0,
                            disabled: true,
                    });
                }
            }
        }
        self.my_nominations.insert(account_id, nominations);
    }

    fn update_choosen_details(&self, index: usize) {
        if let Some(action_tx) = &self.action_tx {
            let (selected_account_id, selected_points) = self.filtered_vector
                .get(index)
                .map(|data| (data.account_id, data.points))
                .unwrap_or_default();

            let _ = action_tx.send(Action::SetChoosenValidator(
                    selected_account_id,
                    selected_points,
                    self.total_points));
        }
    }

    fn clear_choosen(&mut self) {
        self.checked_validators.clear();
    }

    fn choose_current_nominated(&mut self) {
        self.clear_choosen();
        self.checked_validators.extend(self.my_nominations
            .get(&self.account_id)
            .map(|nom| nom.targets.clone())
            .unwrap_or_default());
    }

    fn choose_all_validators(&mut self) {
        self.clear_choosen();
        self.checked_validators.extend(self.individual
            .iter().map(|ind| ind.account_id));
    }

    fn swap_choosen_filter(&mut self) {
        let is_individual = self.filtered_vector.len() == self.individual.len();
        self.filtered_vector = self.individual
            .iter()
            .filter_map(|data| {
                let is_good = !is_individual || self.checked_validators.contains(&data.account_id);
                is_good.then(|| data.clone())
            })
            .collect::<Vec<_>>();
        self.scroll_state = self.scroll_state.content_length(self.filtered_vector.len());
        if self.filtered_vector.len() == 0 {
            self.table_state.select(None);
            self.scroll_state = self.scroll_state.position(0);
        } else {
            self.first_row();
        }
    }

    fn flip_validator_check(&mut self) {
        if let Some(index) = self.table_state.selected() {
            if let Some(indiv) = self.filtered_vector.get(index) {
                let current_account_id = indiv.account_id;
                if self.checked_validators.contains(&current_account_id) {
                    self.checked_validators.remove(&current_account_id);
                } else {
                    self.checked_validators.insert(current_account_id);
                }
            }
        }
    }

    fn save_validator_name(&mut self, new_name: String) {
        if let Some(index) = self.table_state.selected() {
            let account_id = self.filtered_vector[index].account_id;
            let _ = self.known_validators.insert(account_id, new_name);

            let mut file = File::create(&self.known_validators_file)
                .expect("file should be accessible; qed");

            for (account_id, name) in self.known_validators.iter() {
                let seed = hex::encode(account_id);
                writeln!(file, "{}:0x{}", &name, &seed).unwrap();
            }
        }
    }

    fn update_known_validator_record(&mut self) {
        if self.table_state.selected().is_some() {
            if let Some(action_tx) = &self.action_tx {
                let _ = action_tx.send(Action::RenameKnownValidatorRecord);
            }
        }
    }

    fn read_known_validators(&mut self, file_path: &PathBuf) -> Result<()> {
        if let Ok(file) = File::open(file_path) {
            let reader = BufReader::new(file);
            for line in reader.lines() {
                let line = line?.replace("\n", "");
                let line_split_at = line.find(":").unwrap_or(line.len());
                let (name, seed) = line.split_at(line_split_at);
                let seed_str = &seed[3..];

                let account_id: [u8; 32] = hex::decode(seed_str)
                    .expect("stored seed is valid hex string; qed")
                    .as_slice()
                    .try_into()
                    .expect("stored seed is valid length; qed");

                let _ = self.known_validators.insert(account_id, name.to_string());
            }
        }
        Ok(())
    }

    fn first_row(&mut self) {
        if self.filtered_vector.len() > 0 {
            self.move_selected(0);
        }
    }

    fn next_row(&mut self) {
        let i = match self.table_state.selected() {
            Some(i) => {
                if i >= self.filtered_vector.len() - 1 {
                    i
                } else {
                    i + 1
                }
            },
            None => 0,
        };
        self.move_selected(i);
    }

    fn last_row(&mut self) {
        if self.filtered_vector.len() > 0 {
            let last = self.filtered_vector.len() - 1;
            self.move_selected(last);
        }
    }

    fn previous_row(&mut self) {
        let i = match self.table_state.selected() {
            Some(i) => {
                if i == 0 {
                    0
                } else {
                    i - 1
                }
            },
            None => 0
        };
        self.move_selected(i);
    }

    fn update_era_rewards(
        &mut self, 
        era_index: u32, 
        total_points: u32,
        individual: &Vec<EraRewardPoints>,
    ) {
        let previous_length = self.individual.len();
        self.individual = individual.to_vec();
        self.total_points = total_points;
        self.era_index = era_index;

        if individual.len() > 0 {
            if let Some(account_id) = self.my_stash_id {
                if let Some(index) = self.individual
                    .iter()
                    .position(|item| item.account_id == account_id) {
                        self.individual.swap(0, index);
                }
            }
            if previous_length == 0 {
                self.filtered_vector = self.individual.clone();
                self.scroll_state = self.scroll_state.content_length(self.individual.len());
                self.first_row();
            }
        }
    }

    fn nominate_choosen(&mut self) {
        if self.my_stash_id.map(|acc| acc == self.account_id).unwrap_or_default() {
            if let Some(action_tx) = &self.action_tx {
                let _ = action_tx.send(Action::EventLog(
                        "nomination from stash account will stop node validation, use another account for nomination".to_string(), 
                        ActionLevel::Error, 
                        ActionTarget::WalletLog));
            }
        } else {
            if let Some(network_tx) = &self.network_tx {
                let nominate_targets: Vec<[u8; 32]> = self.checked_validators
                    .clone()
                    .into_iter()
                    .collect::<Vec<_>>();
                let _ = network_tx.send(Action::NominateTargets(
                        self.account_secret_seed, nominate_targets));
            }
        }
        self.close_popup();
    }

    fn prepare_nomination_line(&self) -> String {
        let empty_nominations = Nominations::default();
        let nominations = self.my_nominations
            .get(&self.account_id)
            .unwrap_or(&empty_nominations);

        if nominations.targets.len() == 0 {
            "No nominations found".to_string()
        } else {
            let status = if nominations.suppressed {
                "Suppressed"
            } else {
                "Active"
            };
            format!("Submitted at era #{} | {} ", 
                nominations.submitted_in,
                status,
            )
        }
    }
}

impl PartialComponent for CurrentValidators {
    fn set_active(&mut self, current_tab: CurrentTab) {
        match current_tab {
            CurrentTab::CurrentValidatorsPopup => self.is_active = true,
            _ => self.is_active = false,
        }
    }
}

impl Component for CurrentValidators {
    fn register_action_handler(&mut self, tx: UnboundedSender<Action>) -> Result<()> {
        self.action_tx = Some(tx);
        Ok(())
    }

    fn register_network_handler(&mut self, tx: Sender<Action>) -> Result<()> {
        self.network_tx = Some(tx);
        Ok(())
    }

    fn register_config_handler(&mut self, config: Config) -> Result<()> {
        if let Some(style) = config.styles.get(&crate::app::Mode::Wallet) {
            self.palette.with_normal_style(style.get("normal_style").copied());
            self.palette.with_hover_style(style.get("hover_style").copied());
            self.palette.with_normal_border_style(style.get("normal_border_style").copied());
            self.palette.with_hover_border_style(style.get("hover_border_style").copied());
            self.palette.with_normal_title_style(style.get("normal_title_style").copied());
            self.palette.with_hover_title_style(style.get("hover_title_style").copied());
            self.palette.with_highlight_style(style.get("highlight_style").copied());
            self.palette.with_scrollbar_style(style.get("scrollbar_style").copied());
        }
        let mut known_validators_file = config.config.data_dir;
        known_validators_file.push(Self::KNOWN_VALIDATORS_FILE);
        self.read_known_validators(&known_validators_file)?;
        self.known_validators_file = known_validators_file;
        Ok(())
    }

    fn update(&mut self, action: Action) -> Result<Option<Action>> {
        match action {
            Action::UpdateKnownValidator(validator_name) => self.save_validator_name(validator_name),
            Action::UsedAccount(account_id, secret_seed) => self.update_used_account(account_id, secret_seed),
            Action::SetNominatorsByAccount(nominations, account_id) => self.store_nominators(nominations, account_id),
            Action::SetStashAccount(account_id) => self.my_stash_id = Some(account_id),
            Action::SetCurrentValidatorEraRewards(era_index, total_points, individual) => 
                self.update_era_rewards(era_index, total_points, &individual),
            _ => {}
        };
        Ok(None)
    }

    fn handle_key_event(&mut self, key: KeyEvent) -> Result<Option<Action>> {
        if self.is_active {
            match key.code {
                KeyCode::Up | KeyCode::Char('k') => self.previous_row(), 
                KeyCode::Down | KeyCode::Char('j') => self.next_row(), 
                KeyCode::Char('g') => self.first_row(),
                KeyCode::Char('G') => self.last_row(),
                KeyCode::Char('R') => self.update_known_validator_record(),

                KeyCode::Char('c') => self.clear_choosen(),
                KeyCode::Char('m') => self.choose_current_nominated(),
                KeyCode::Char('a') => self.choose_all_validators(),
                KeyCode::Char('f') => self.swap_choosen_filter(),

                KeyCode::Char('N') => self.nominate_choosen(),
                KeyCode::Enter => self.flip_validator_check(),
                KeyCode::Esc => self.close_popup(),
                _ => {},
            };
        }
        Ok(None)
    }

    fn draw(&mut self, frame: &mut Frame, area: Rect) -> Result<()> {
        if self.is_active {
            let (border_style, border_type) = self.palette.create_border_style(self.is_active);
            let [place, _] = super::nominator_layout(area);

            let top_title = format!("Validators {} | Total points: {}", self.individual.len(), self.total_points);
            let bottom_title = self.prepare_nomination_line();

            let table = Table::new(
                self.filtered_vector
                    .iter()
                    .chain(&self.not_active_nominations)
                    .enumerate()
                    .map(|(index, info)| {
                        let is_validator_choosen = self.checked_validators.contains(&info.account_id);
                        let is_current_nomination = self.my_nominations
                            .get(&self.account_id)
                            .map(|x| x.targets.contains(&info.account_id))
                            .unwrap_or_default();

                        let mut address_text = Text::from(info.address.clone()).alignment(Alignment::Center);
                        let mut points_text = Text::from(info.points.to_string()).alignment(Alignment::Right);

                        let (row_style, is_choosen_text) = if is_validator_choosen {
                            address_text = address_text.add_modifier(Modifier::ITALIC);
                            points_text = points_text.add_modifier(Modifier::ITALIC);
                            (self.palette.create_highlight_style(), ">")
                        } else if is_current_nomination {
                            (Default::default(), "*")
                        } else {
                            (Default::default(), "")
                        };

                        if info.disabled {
                            address_text = address_text.add_modifier(Modifier::CROSSED_OUT);
                            points_text = points_text.add_modifier(Modifier::CROSSED_OUT);
                        }

                        let default_name = if index == 0 && self.my_stash_id
                            .map(|account_id| account_id == info.account_id)
                            .unwrap_or_default() == true {
                                "My stash"
                            } else {
                                "Ghostie"
                            };

                        let name = self.known_validators
                            .get(&info.account_id)
                            .cloned()
                            .unwrap_or(default_name.to_string());

                        Row::new(vec![
                            Cell::from(Text::from(is_choosen_text).alignment(Alignment::Left)),
                            Cell::from(Text::from(name).alignment(Alignment::Left)),
                            Cell::from(address_text),
                            Cell::from(points_text), 
                        ]).style(row_style)
                    }),
                [
                    Constraint::Length(1),
                    Constraint::Length(12),
                    Constraint::Min(0),
                    Constraint::Length(6),
                ],
            )
                .style(self.palette.create_basic_style(false))
                .highlight_style(self.palette.create_basic_style(true))
                .column_spacing(1)
                .block(Block::bordered()
                    .border_style(border_style)
                    .border_type(border_type)
                    .padding(Padding::right(2))
                    .title_style(self.palette.create_title_style(false))
                    .title_bottom(Line::from(bottom_title).left_aligned())
                    .title_top(Line::from(top_title).right_aligned()));

            let scrollbar = Scrollbar::default()
                .orientation(ScrollbarOrientation::VerticalRight)
                .begin_symbol(None)
                .end_symbol(None)
                .style(self.palette.create_scrollbar_style());

            frame.render_widget(Clear, place);
            frame.render_stateful_widget(table, place, &mut self.table_state);
            frame.render_stateful_widget(
                scrollbar,
                place.inner(Margin { vertical: 1, horizontal: 1 }),
                &mut self.scroll_state,
            );
        }

        Ok(())
    }
}