/*
 * This file is part of ComputerCraft - http://www.computercraft.info
 * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
 * Send enquiries to dratcliffe@gmail.com
 */
package dan200.computercraft.client.render;

import dan200.computercraft.ComputerCraft;
import dan200.computercraft.shared.media.items.ItemPrintout;
import net.minecraft.client.renderer.GlStateManager;
import net.minecraft.item.ItemStack;
import net.minecraftforge.client.event.RenderItemInFrameEvent;
import net.minecraftforge.client.event.RenderSpecificHandEvent;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.fml.relauncher.Side;

import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
import static dan200.computercraft.client.render.PrintoutRenderer.*;
import static dan200.computercraft.shared.media.items.ItemPrintout.LINES_PER_PAGE;
import static dan200.computercraft.shared.media.items.ItemPrintout.LINE_MAX_LENGTH;

/**
 * Emulates map and item-frame rendering for printouts.
 */
@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
public final class ItemPrintoutRenderer extends ItemMapLikeRenderer
{
    private static final ItemPrintoutRenderer INSTANCE = new ItemPrintoutRenderer();

    private ItemPrintoutRenderer()
    {
    }

    @SubscribeEvent
    public static void onRenderInHand( RenderSpecificHandEvent event )
    {
        ItemStack stack = event.getItemStack();
        if( stack.getItem() != ComputerCraft.Items.printout ) return;

        event.setCanceled( true );

        INSTANCE.renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
    }

    @Override
    protected void renderItem( ItemStack stack )
    {
        // Setup various transformations. Note that these are partially adapated from the corresponding method
        // in ItemRenderer.renderMapFirstPerson
        GlStateManager.disableLighting();

        GlStateManager.rotate( 180f, 0f, 1f, 0f );
        GlStateManager.rotate( 180f, 0f, 0f, 1f );
        GlStateManager.scale( 0.42f, 0.42f, -0.42f );
        GlStateManager.translate( -0.5f, -0.48f, 0.0f );

        drawPrintout( stack );

        GlStateManager.enableLighting();
    }

    @SubscribeEvent
    public static void onRenderInFrame( RenderItemInFrameEvent event )
    {
        ItemStack stack = event.getItem();
        if( stack.getItem() != ComputerCraft.Items.printout ) return;

        event.setCanceled( true );

        GlStateManager.disableLighting();

        // Move a little bit forward to ensure we're not clipping with the frame
        GlStateManager.translate( 0.0f, 0.0f, -0.001f );
        GlStateManager.rotate( 180f, 0f, 0f, 1f );
        GlStateManager.scale( 0.95f, 0.95f, -0.95f );
        GlStateManager.translate( -0.5f, -0.5f, 0.0f );

        drawPrintout( stack );

        GlStateManager.enableLighting();
        GlStateManager.disableBlend();
    }

    private static void drawPrintout( ItemStack stack )
    {
        int pages = ItemPrintout.getPageCount( stack );
        boolean book = ItemPrintout.getType( stack ) == ItemPrintout.Type.Book;

        double width = LINE_MAX_LENGTH * FONT_WIDTH + X_TEXT_MARGIN * 2;
        double height = LINES_PER_PAGE * FONT_HEIGHT + Y_TEXT_MARGIN * 2;

        // Non-books will be left aligned
        if( !book ) width += offsetAt( pages );

        double visualWidth = width, visualHeight = height;

        // Meanwhile books will be centred
        if( book )
        {
            visualWidth += 2 * COVER_SIZE + 2 * offsetAt( pages );
            visualHeight += 2 * COVER_SIZE;
        }

        double max = Math.max( visualHeight, visualWidth );

        // Scale the printout to fit correctly.
        double scale = 1.0 / max;
        GlStateManager.scale( scale, scale, scale );
        GlStateManager.translate( (max - width) / 2.0f, (max - height) / 2.0f, 0.0f );

        drawBorder( 0, 0, -0.01, 0, pages, book );
        drawText( X_TEXT_MARGIN, Y_TEXT_MARGIN, 0, ItemPrintout.getText( stack ), ItemPrintout.getColours( stack ) );
    }
}