// SPDX-License-Identifier: LGPL-2.1-only
// Copyright (C) 2026 Liberux Labs, S. L. <info@liberux.net>

use super::*;
use crate::render::Canvas;

fn solid_rgba( w: u32, h: u32 ) -> Arc<Vec<u8>>
{
	Arc::new( vec![ 255u8; ( w * h * 4 ) as usize ] )
}

fn dummy_canvas() -> Canvas
{
	Canvas::new( 800, 600 )
}

// ── builders / defaults ───────────────────────────────────────────────────

#[ test ]
fn new_uses_documented_defaults()
{
	let img = Image::new( solid_rgba( 4, 4 ), 4, 4 );
	assert_eq!( img.width,  4 );
	assert_eq!( img.height, 4 );
	assert!( !img.cover );
	assert!( img.display_size.is_none() );
	assert_eq!( img.opacity, 1.0 );
}

#[ test ]
fn cover_builder_sets_cover_flag()
{
	let img = Image::new( solid_rgba( 4, 4 ), 4, 4 ).cover();
	assert!( img.cover );
}

#[ test ]
fn size_builder_sets_explicit_display_size()
{
	let img = Image::new( solid_rgba( 4, 4 ), 4, 4 ).size( 120.0, 80.0 );
	assert_eq!( img.display_size, Some( ( Length::px( 120.0 ), Length::px( 80.0 ) ) ) );
}

#[ test ]
fn size_builder_keeps_length_values_for_later_viewport_resolution()
{
	let img = Image::new( solid_rgba( 4, 4 ), 4, 4 ).size( -10.0, -20.0 );
	assert_eq!( img.display_size, Some( ( Length::px( -10.0 ), Length::px( -20.0 ) ) ) );
}

#[ test ]
fn opacity_clamps_to_unit_interval()
{
	assert_eq!( Image::new( solid_rgba( 1, 1 ), 1, 1 ).opacity( -0.5 ).opacity, 0.0 );
	assert_eq!( Image::new( solid_rgba( 1, 1 ), 1, 1 ).opacity(  1.5 ).opacity, 1.0 );
	assert_eq!( Image::new( solid_rgba( 1, 1 ), 1, 1 ).opacity(  0.5 ).opacity, 0.5 );
}

// ── preferred_size ────────────────────────────────────────────────────────

#[ test ]
fn preferred_size_default_scales_height_to_match_width_aspect()
{
	// 200×100 source image at max_width = 400 → scale = 2 → height 200.
	let img = Image::new( solid_rgba( 200, 100 ), 200, 100 );
	let ( w, h ) = img.preferred_size( 400.0, &dummy_canvas() );
	assert_eq!( w, 400.0 );
	assert_eq!( h, 200.0 );
}

#[ test ]
fn preferred_size_with_explicit_size_wins_over_aspect_logic()
{
	let img = Image::new( solid_rgba( 200, 100 ), 200, 100 ).size( 50.0, 25.0 );
	assert_eq!( img.preferred_size( 1000.0, &dummy_canvas() ), ( 50.0, 25.0 ) );
}

#[ test ]
fn preferred_size_resolves_explicit_viewport_lengths()
{
	let img = Image::new( solid_rgba( 200, 100 ), 200, 100 ).size( Length::vw( 10.0 ), Length::vh( 10.0 ) );
	let canvas = Canvas::new( 480, 900 );
	assert_eq!( img.preferred_size( 1000.0, &canvas ), ( 48.0, 90.0 ) );
}

#[ test ]
fn preferred_size_cover_mode_keeps_aspect_ratio()
{
	// 100×50 source in cover mode at max_width = 300 → height = 300 * (50/100) = 150.
	let img = Image::new( solid_rgba( 100, 50 ), 100, 50 ).cover();
	let ( w, h ) = img.preferred_size( 300.0, &dummy_canvas() );
	assert_eq!( w, 300.0 );
	assert_eq!( h, 150.0 );
}

#[ test ]
fn preferred_size_cover_and_default_match_for_uniform_scaling()
{
	// When the source aspect matches the requested width, cover and the
	// default fit-width path produce identical sizes — they only diverge
	// when the source is taller than wide.
	let normal  = Image::new( solid_rgba( 100, 50 ), 100, 50 );
	let covered = Image::new( solid_rgba( 100, 50 ), 100, 50 ).cover();
	let c = dummy_canvas();
	assert_eq!( normal.preferred_size( 200.0, &c ), covered.preferred_size( 200.0, &c ) );
}

#[ test ]
fn short_side_sizes_by_width_in_portrait_keeping_aspect()
{
	// 200×100 source, portrait 480×900 → short side is the width.
	// orient( 40, 5 ) portrait → 40 % of 480 = 192 width, height 192*(100/200)=96.
	let img    = Image::new( solid_rgba( 200, 100 ), 200, 100 ).short_side( Length::orient( 40.0, 5.0 ) );
	let canvas = Canvas::new( 480, 900 );
	assert_eq!( img.preferred_size( 1000.0, &canvas ), ( 192.0, 96.0 ) );
}

#[ test ]
fn short_side_sizes_by_height_in_landscape_keeping_aspect()
{
	// 200×100 source, landscape 900×480 → short side is the height.
	// orient( 40, 5 ) landscape → 5 % of 480 = 24 height, width 24*(200/100)=48.
	let img    = Image::new( solid_rgba( 200, 100 ), 200, 100 ).short_side( Length::orient( 40.0, 5.0 ) );
	let canvas = Canvas::new( 900, 480 );
	assert_eq!( img.preferred_size( 1000.0, &canvas ), ( 48.0, 24.0 ) );
}

// ── Arc sharing ───────────────────────────────────────────────────────────

#[ test ]
fn rgba_buffer_is_shared_via_arc_not_cloned_per_image()
{
	let bytes = solid_rgba( 8, 8 );
	let strong_before = Arc::strong_count( &bytes );

	let img = Image::new( bytes.clone(), 8, 8 );
	assert_eq!( Arc::strong_count( &bytes ), strong_before + 1 );

	// Same buffer goes into a second image — strong count rises again.
	let img2 = Image::new( bytes.clone(), 8, 8 );
	assert_eq!( Arc::strong_count( &bytes ), strong_before + 2 );

	drop( img );
	drop( img2 );
	assert_eq!( Arc::strong_count( &bytes ), strong_before );
}