use eframe::egui::{self, Color32, Stroke, Vec2};
use std::path::PathBuf;

pub struct DropZone {
    is_hovering: bool,
}

impl DropZone {
    pub fn new() -> Self {
        Self { is_hovering: false }
    }

    pub fn show<F>(&mut self, ui: &mut egui::Ui, mut on_files_dropped: F)
    where
        F: FnMut(Vec<PathBuf>),
    {
        let available_width = ui.available_width();
        let height = 140.0;

        // Check for drag-and-drop hover state
        let is_hovering = ui.ctx().input(|i| !i.raw.hovered_files.is_empty());
        self.is_hovering = is_hovering;

        // Style based on hover state
        let (bg_color, stroke_color, stroke_width) = if self.is_hovering {
            (
                Color32::from_rgba_unmultiplied(100, 149, 237, 30), // Cornflower blue, semi-transparent
                Color32::from_rgb(100, 149, 237),
                2.0,
            )
        } else {
            (
                Color32::from_gray(40),
                Color32::from_gray(80),
                1.0,
            )
        };

        let (rect, response) = ui.allocate_exact_size(Vec2::new(available_width, height), egui::Sense::click());

        // Draw background
        ui.painter().rect(
            rect,
            8.0,
            bg_color,
            Stroke::new(stroke_width, stroke_color),
        );

        // Draw dashed border effect (using multiple small rects)
        if !self.is_hovering {
            let dash_length = 10.0;
            let gap = 5.0;
            let inset = 4.0;
            let inner_rect = rect.shrink(inset);

            // Top and bottom
            let mut x = inner_rect.min.x;
            while x < inner_rect.max.x - dash_length {
                ui.painter().line_segment(
                    [egui::pos2(x, inner_rect.min.y), egui::pos2(x + dash_length, inner_rect.min.y)],
                    Stroke::new(1.0, Color32::from_gray(60)),
                );
                ui.painter().line_segment(
                    [egui::pos2(x, inner_rect.max.y), egui::pos2(x + dash_length, inner_rect.max.y)],
                    Stroke::new(1.0, Color32::from_gray(60)),
                );
                x += dash_length + gap;
            }

            // Left and right
            let mut y = inner_rect.min.y;
            while y < inner_rect.max.y - dash_length {
                ui.painter().line_segment(
                    [egui::pos2(inner_rect.min.x, y), egui::pos2(inner_rect.min.x, y + dash_length)],
                    Stroke::new(1.0, Color32::from_gray(60)),
                );
                ui.painter().line_segment(
                    [egui::pos2(inner_rect.max.x, y), egui::pos2(inner_rect.max.x, y + dash_length)],
                    Stroke::new(1.0, Color32::from_gray(60)),
                );
                y += dash_length + gap;
            }
        }

        // Text colors
        let text_color = if self.is_hovering {
            Color32::WHITE
        } else {
            Color32::from_gray(180)
        };

        let font = egui::FontId::proportional(20.0);
        let hint_font = egui::FontId::proportional(15.0);

        // Calculate vertical positions for all text elements to be visually centered together
        // Main text line height ~24px, hint ~18px, spacing between ~12px
        // Total height: 24 + 24 + 12 + 18 = ~78px for non-hover, center that in rect
        let total_text_height = 78.0;
        let top_of_text = rect.center().y - total_text_height / 2.0;

        if self.is_hovering {
            // Single line when hovering - center it
            ui.painter().text(
                rect.center(),
                egui::Align2::CENTER_CENTER,
                "Drop files here",
                font,
                text_color,
            );
        } else {
            // Line 1: "Drag and drop files here"
            ui.painter().text(
                egui::pos2(rect.center().x, top_of_text + 12.0),
                egui::Align2::CENTER_CENTER,
                "Drag and drop files here",
                font.clone(),
                text_color,
            );
            // Line 2: "or click to browse"
            ui.painter().text(
                egui::pos2(rect.center().x, top_of_text + 38.0),
                egui::Align2::CENTER_CENTER,
                "or click to browse",
                font,
                text_color,
            );
            // Hint line at bottom of text block
            ui.painter().text(
                egui::pos2(rect.center().x, top_of_text + 66.0),
                egui::Align2::CENTER_CENTER,
                "GIF, PNG, JPEG, WebP, MP4, MOV, WebM",
                hint_font,
                Color32::from_gray(140),
            );
        }

        // Handle click to open file dialog
        if response.clicked() {
            let dialog = rfd::FileDialog::new()
                .add_filter("All Supported", &["gif", "png", "jpg", "jpeg", "webp", "mp4", "mov", "webm", "mkv", "avi", "m4v"])
                .add_filter("Images", &["gif", "png", "jpg", "jpeg", "webp"])
                .add_filter("Videos", &["mp4", "mov", "webm", "mkv", "avi", "m4v"]);

            if let Some(paths) = dialog.pick_files() {
                on_files_dropped(paths);
            }
        }
    }
}