#!/usr/bin/env bash
#
# Create a christmas tree on the terminal
#
# Author: Dave Eddy <dave@daveeddy.com>
# Date: December 24, 2024
# License: MIT

# colors
color_tree=$(tput setaf 2)
color_star=$(tput setaf 227)

# lights - dave matched these to "vintaglo vintage christmas lights"
color_lights=(
	"$(tput setaf 111)"
	"$(tput setaf 208)"
	"$(tput setaf 198)"
	"$(tput setaf 155)"
)
len=${#color_lights[@]}

# the tree itself - each number represents a specific "light" color
IFS= read -r -d '' TREE <<-"EOF"
                  *                           *                           *                          
                 / \                         / \                         / \                         
                / 0 \                       / 0 \                       / 0 \                       
               / 1   \                     / 1   \                     / 1   \                     
              /       \                   /       \                   /       \                   
             /_ 2  1  _\                 /_ 2  1  _\                 /_ 2  1  _\                 
              /       \                   /       \                   /       \                  
             /  1   2  \                 /  1   2  \                 /  1   2  \                 
            /           \               /           \               /           \               
           /   0  3  0   \             /   0  3  0   \             /   0  3  0   \             
          /_        1    _\           /_       1     _\           /_        1    _\           
           /    2        \             /    2         \            /    2        \            
          /  1   0   0    \           /  1   0   0     \          /  1   0   0    \           
         /    3         3  \         /    3         3   \        /    3         3  \         
        /  2        1       \       /  2        1        \      /  2        1       \       
        ---------------------       ---------------------       ---------------------       
                 |||                         |||                         |||                
                /|||\                       /|||\                       /|||\               
EOF
TREE_HEIGHT=18

MESSAGE=(
	"${color_lights[3]}Merry Christmas!"
	"${color_lights[3]}From Dom Charoenyos"
	"${color_lights[1]}$ ${color_lights[0]}curl -s https://xmas.dome.cloud | bash"
	"${color_lights[2]}$ ${color_lights[3]}based on xmas.ysap.sh"

)

# configure terminal for drawing
cleanup() {
	tput rmcup
	tput cnorm
}
trap cleanup exit
tput smcup
tput civis

# figure out our size
COLS=$(tput cols)
LINES=$(tput lines)
middle_y=$((LINES / 2 - (TREE_HEIGHT / 2)))

# current color index
idx=0
while true; do
	# stylize and colorize tree
	t=$color_tree$TREE
	t=${t// \*/ ${color_star}*${color_tree} }
	t=${t// 0 / ${color_lights[idx % len]}o${color_tree} }
	t=${t// 1 / ${color_lights[(idx + 1) % len]}o${color_tree} }
	t=${t// 2 / ${color_lights[(idx + 2) % len]}o${color_tree} }
	t=${t// 3 / ${color_lights[(idx + 3) % len]}o${color_tree} }

	# display the tree
	tput cup "$middle_y" 0
	echo "$t"

	# display the text
	y=$((middle_y + 7))
	for line in "${MESSAGE[@]}"; do
		tput cup "$y" 95
		echo "$line"
		((y++))
	done

	# increment the lights and pause for the animation to play
	((idx++))
	sleep 1
done