// Copyright 2023 The Grim Developers
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use chrono::{DateTime, NaiveDateTime, Utc};
use eframe::epaint::{Color32, Rounding, Stroke};
use egui::{RichText, ScrollArea, Spinner, Widget};
use grin_servers::DiffBlock;

use crate::gui::Colors;
use crate::gui::icons::{AT, COINS, CUBE_TRANSPARENT, HASH, HOURGLASS_LOW, HOURGLASS_MEDIUM, TIMER};
use crate::gui::views::{Network, NetworkTab, View};
use crate::node::Node;

#[derive(Default)]
pub struct NetworkMetrics;

const BLOCK_REWARD: f64 = 60.0;
// 1 year is calculated as 365 days and 6 hours (31557600).
const YEARLY_SUPPLY: f64 = ((60 * 60 * 24 * 365) + 6 * 60 * 60) as f64;

impl NetworkTab for NetworkMetrics {
    fn name(&self) -> String {
        t!("network.metrics")
    }

    fn ui(&mut self, ui: &mut egui::Ui) {
        let server_stats = Node::get_stats();
        if server_stats.is_none() || server_stats.as_ref().unwrap().diff_stats.height == 0 {
            if !Node::is_running() {
                Network::disabled_server_content(ui);
            } else {
                View::center_content(ui, 160.0, |ui| {
                    Spinner::new().size(104.0).color(Colors::GOLD).ui(ui);
                    ui.add_space(18.0);
                    ui.label(RichText::new(t!("network_metrics.loading"))
                        .size(16.0)
                        .color(Colors::TEXT)
                    );
                });
            }
            return;
        }

        let stats = server_stats.as_ref().unwrap();

        // Show emission info
        ui.vertical_centered_justified(|ui| {
            View::sub_header(ui, format!("{} {}", COINS, t!("network_metrics.emission")));
        });
        ui.add_space(4.0);

        let supply = stats.header_stats.height as f64 * BLOCK_REWARD;
        let rate = (YEARLY_SUPPLY * 100.0) / supply;

        ui.columns(3, |columns| {
            columns[0].vertical_centered(|ui| {
                View::rounded_box(ui,
                                  format!("{}ツ", BLOCK_REWARD),
                                  t!("network_metrics.reward"),
                                  [true, false, true, false]);
            });
            columns[1].vertical_centered(|ui| {
                View::rounded_box(ui,
                                  format!("{:.2}%", rate),
                                  t!("network_metrics.inflation"),
                                  [false, false, false, false]);
            });
            columns[2].vertical_centered(|ui| {
                View::rounded_box(ui,
                                  supply.to_string(),
                                  t!("network_metrics.supply"),
                                  [false, true, false, true]);
            });
        });
        ui.add_space(6.0);

        // Show difficulty adjustment window info
        ui.vertical_centered_justified(|ui| {
            let title = t!(
                "network_metrics.difficulty_window",
                "size" => stats.diff_stats.window_size
            );
            View::sub_header(ui, format!("{} {}", HOURGLASS_MEDIUM, title));
        });
        ui.add_space(4.0);
        ui.columns(3, |columns| {
            columns[0].vertical_centered(|ui| {
                View::rounded_box(ui,
                                  stats.diff_stats.height.to_string(),
                                  t!("network_node.height"),
                                  [true, false, true, false]);
            });
            columns[1].vertical_centered(|ui| {
                View::rounded_box(ui,
                                  format!("{}s", stats.diff_stats.average_block_time),
                                  t!("network_metrics.block_time"),
                                  [false, false, false, false]);
            });
            columns[2].vertical_centered(|ui| {
                View::rounded_box(ui,
                                  stats.diff_stats.average_difficulty.to_string(),
                                  t!("network_node.difficulty"),
                                  [false, true, false, true]);
            });
        });
        ui.add_space(6.0);

        // Show difficulty adjustment window blocks
        let blocks_size = stats.diff_stats.last_blocks.len();
        ScrollArea::vertical()
            .auto_shrink([false; 2])
            .stick_to_bottom(true)
            .id_source("difficulty_scroll")
            .show_rows(
                ui,
                DIFF_BLOCK_UI_HEIGHT,
                blocks_size,
                |ui, row_range| {
                    for index in row_range {
                        let db = stats.diff_stats.last_blocks.get(index).unwrap();
                        let rounding = if blocks_size == 1 {
                            [true, true]
                        } else if index == 0 {
                            [true, false]
                        } else if index == blocks_size - 1 {
                            [false, true]
                        } else {
                            [false, false]
                        };
                        draw_diff_block(ui, db, rounding)
                    }
                },
            );
    }
}

const DIFF_BLOCK_UI_HEIGHT: f32 = 77.0;

fn draw_diff_block(ui: &mut egui::Ui, db: &DiffBlock, rounding: [bool; 2]) {
    // Add space before first item
    if rounding[0] {
        ui.add_space(4.0);
    }

    ui.horizontal(|ui| {
        ui.add_space(6.0);
        ui.vertical(|ui| {
            let mut rect = ui.available_rect_before_wrap();
            rect.set_height(DIFF_BLOCK_UI_HEIGHT);
            ui.painter().rect(
                rect,
                Rounding {
                    nw: if rounding[0] { 8.0 } else { 0.0 },
                    ne: if rounding[0] { 8.0 } else { 0.0 },
                    sw: if rounding[1] { 8.0 } else { 0.0 },
                    se: if rounding[1] { 8.0 } else { 0.0 },
                },
                Color32::WHITE,
                Stroke { width: 1.0, color: Colors::ITEM_STROKE }
            );

            ui.add_space(2.0);
            ui.horizontal_top(|ui| {
                ui.add_space(5.0);
                ui.heading(RichText::new(HASH)
                    .color(Colors::BLACK)
                    .size(18.0));
                ui.add_space(2.0);

                // Draw block hash
                ui.heading(RichText::new(db.block_hash.to_string())
                    .color(Colors::BLACK)
                    .size(18.0));
            });
            ui.horizontal_top(|ui| {
                ui.add_space(6.0);
                ui.heading(RichText::new(CUBE_TRANSPARENT)
                    .color(Colors::TITLE)
                    .size(16.0));
                ui.add_space(4.0);

                // Draw block difficulty and height
                ui.heading(RichText::new(db.difficulty.to_string())
                    .color(Colors::TITLE)
                    .size(16.0));
                ui.add_space(2.0);
                ui.heading(RichText::new(AT).color(Colors::TITLE).size(16.0));
                ui.add_space(2.0);
                ui.heading(RichText::new(db.block_height.to_string())
                    .color(Colors::TITLE)
                    .size(16.0));
            });
            ui.horizontal_top(|ui| {
                ui.add_space(6.0);
                ui.heading(RichText::new(TIMER)
                    .color(Colors::GRAY)
                    .size(16.0));
                ui.add_space(4.0);

                // Draw block time
                ui.heading(RichText::new(format!("{}s", db.duration))
                    .color(Colors::GRAY)
                    .size(16.0));
                ui.add_space(2.0);
                ui.heading(RichText::new(HOURGLASS_LOW).color(Colors::GRAY).size(16.0));
                ui.add_space(2.0);

                let naive_datetime = NaiveDateTime::from_timestamp_opt(db.time as i64, 0);
                if naive_datetime.is_some() {
                    let datetime: DateTime<Utc> = DateTime::from_utc(naive_datetime.unwrap(), Utc);
                    ui.heading(RichText::new(datetime.to_string())
                        .color(Colors::GRAY)
                        .size(16.0));
                }
            });
            ui.add_space(2.0);
        });
    });
}