require "benchmark"
require "./utilities.cr"
require "./db-cars.cr"

# List of environment variables and default values:
# ENV["CARNAME"]          rescue "Corvet-#{(db_size/2).to_i}"
# ENV["CARCOLOR"]         rescue "red"
# ENV["CARKEYWORD"]       rescue "spacious"
# ENV["DBSIZE"]           rescue 50_000
# ENV["DBSIZE_START"]     rescue 1_000
# ENV["DBSIZE_INCREMENT"] rescue 1_000
# ENV["REPORT_DIR"]       rescue "results"
# ENV["NBRUN"]            rescue 100
# ENV["MAXINDEXES"]       rescue 5_000
# ENV["LRU_SIZE"]         rescue 10_000

class Context
	class_property report_dir = "results"
	class_property max_indexes = 5_000
	class_property nb_run      = 100
	class_property from        = 1_000
	class_property to          = 50_000
	class_property incr        = 1_000
	class_property lru_size    : UInt32 = 10_000
end

# To simplify the creation of graphs, it's better to have fake data for
# partitions and tags that won't be actually covered.
# 0 means the absence of data.
def fake_report(name)
	durations = Array(Int32).new Context.nb_run, 0
	File.open("#{Context.report_dir}/#{name}.raw", "w") do |file|
		durations.each do |d|
			file.puts d
		end
	end
	puts "#{name}: no report"
end
def report(storage, name, &block)
	durations = run_n_times Context.nb_run, &block
	File.open("#{Context.report_dir}/#{name}.raw", "w") do |file|
		durations.each do |d|
			file.puts d
		end
	end
	avr = durations.reduce { |a, b| a + b }  / Context.nb_run
	puts "#{name}: #{avr}"
	avr
end

def verbose_add_cars(storage, nbcars, name, max_indexes)
	long_operation "add #{nbcars} values to #{name}" do
		add_cars storage, nbcars, max_indexes: max_indexes
	end
end

#  Add first entries, then loop: speed tests, add entries.
def prepare_env(storage, name, s_index, s_partition, s_tags, &)
	verbose_add_cars storage, Context.from, name, max_indexes: Context.max_indexes

	current = Context.from
	to = Context.to
	incr = Context.incr

	while current < to
		yield storage, current, name, s_index, s_partition, s_tags

		break if current + incr >= to

		verbose_add_cars storage, incr, name, max_indexes: Context.max_indexes
		current += incr
	end

	long_operation "removing #{name} data" { storage.rm_storage_dir }
end

def search_benchmark(storage : DODB::Storage(Car),
		current_db_size : Int32,
		name            : String,
		search_name     : DODB::Trigger::Index(Car),
		search_color    : DODB::Trigger::Partition(Car),
		search_keywords : DODB::Trigger::Tags(Car))
	name_to_search    = ENV["CARNAME"]    rescue "Corvet-#{(current_db_size/2).to_i}"
	color_to_search   = ENV["CARCOLOR"]   rescue "red"
	keyword_to_search = ENV["CARKEYWORD"] rescue "spacious"
	puts "NEW BATCH: db-size #{current_db_size}, name: '#{name_to_search}', color: '#{color_to_search}', tag: '#{keyword_to_search}'"
	report(storage, "#{name}_#{current_db_size}_index") do
		corvet = search_name.get name_to_search
	end
	if current_db_size <= Context.max_indexes
		report(storage, "#{name}_#{current_db_size}_partitions") do
			corvet = search_color.get? color_to_search
		end
		report(storage, "#{name}_#{current_db_size}_tags") do
			corvet = search_keywords.get? keyword_to_search
		end
	else
		fake_report("#{name}_#{current_db_size}_partitions")
		fake_report("#{name}_#{current_db_size}_tags")
	end
end

def bench_searches()
	cars_ram      = SPECDB::RAMOnly(Car).new
	cars_cached   = SPECDB::Cached(Car).new
	cars_lru      = SPECDB::Common(Car).new "-#{Context.lru_size}", Context.lru_size
	cars_semi     = SPECDB::Uncached(Car).new "-semi"
	cars_uncached = SPECDB::Uncached(Car).new

	ram_Sby_name,      ram_Sby_color,      ram_Sby_keywords      = ram_indexes      cars_ram
	cached_Sby_name,   cached_Sby_color,   cached_Sby_keywords   = cached_indexes   cars_cached
	lru_Sby_name,      lru_Sby_color,      lru_Sby_keywords      = cached_indexes   cars_lru
	semi_Sby_name,     semi_Sby_color,     semi_Sby_keywords     = cached_indexes   cars_semi
	uncached_Sby_name, uncached_Sby_color, uncached_Sby_keywords = uncached_indexes cars_uncached

	fn = ->search_benchmark(DODB::Storage(Car), Int32, String, DODB::Trigger::Index(Car), DODB::Trigger::Partition(Car), DODB::Trigger::Tags(Car))

	prepare_env cars_ram,      "ram",      ram_Sby_name,      ram_Sby_color,      ram_Sby_keywords,      &fn
	prepare_env cars_cached,   "cached",   cached_Sby_name,   cached_Sby_color,   cached_Sby_keywords,   &fn
	prepare_env cars_lru,      "lru",      lru_Sby_name,      lru_Sby_color,      lru_Sby_keywords,      &fn
	prepare_env cars_semi,     "semi",     semi_Sby_name,     semi_Sby_color,     semi_Sby_keywords,     &fn
	prepare_env cars_uncached, "uncached", uncached_Sby_name, uncached_Sby_color, uncached_Sby_keywords, &fn
end

def perform_add(storage : DODB::Storage(Car))
	corvet0 = Car.new "Corvet", "red", [ "shiny", "impressive", "fast", "elegant" ]
	i = 0
	perform_benchmark_average Context.nb_run, do
		corvet = corvet0.clone
		corvet.name = "Corvet-#{i}"
		storage.unsafe_add corvet
		i += 1
	end
end

def bench_add()
	cars_ram      = SPECDB::RAMOnly(Car).new
	cars_cached   = SPECDB::Cached(Car).new
	cars_lru      = SPECDB::Common(Car).new "-#{Context.lru_size}", Context.lru_size
	cars_semi     = SPECDB::Uncached(Car).new "-semi"
	cars_uncached = SPECDB::Uncached(Car).new

	ram_indexes      cars_ram
	cached_indexes   cars_cached
	cached_indexes   cars_lru
	cached_indexes   cars_semi
	uncached_indexes cars_uncached

	avr = perform_add(cars_ram)
	puts "(ram db and indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	avr = perform_add(cars_cached)
	puts "(cached db and indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	avr = perform_add(cars_lru)
	puts "(lru db and cached indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	avr = perform_add(cars_semi)
	puts "(uncached db but cached indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	avr = perform_add(cars_uncached)
	puts "(uncached db and indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	cars_ram.rm_storage_dir
	cars_cached.rm_storage_dir
	cars_semi.rm_storage_dir
	cars_uncached.rm_storage_dir
end

def bench_50_shades_of_lru()
	cars_lru1  = SPECDB::Common(Car).new "-1k",  1_000
	cars_lru5  = SPECDB::Common(Car).new "-5k",  5_000
	cars_lru10 = SPECDB::Common(Car).new "-10k", 10_000
	cars_lru20 = SPECDB::Common(Car).new "-20k", 20_000

	lru_Sby_name1,   lru_Sby_color1,   lru_Sby_keywords1   = cached_indexes cars_lru1
	lru_Sby_name5,   lru_Sby_color5,   lru_Sby_keywords5   = cached_indexes cars_lru5
	lru_Sby_name10,  lru_Sby_color10,  lru_Sby_keywords10  = cached_indexes cars_lru10
	lru_Sby_name20,  lru_Sby_color20,  lru_Sby_keywords20  = cached_indexes cars_lru20

	fn = ->search_benchmark(DODB::Storage(Car), Int32, String, DODB::Trigger::Index(Car), DODB::Trigger::Partition(Car), DODB::Trigger::Tags(Car))

	prepare_env cars_lru1,     "lru1",     lru_Sby_name1,     lru_Sby_color1,     lru_Sby_keywords1,     &fn
	prepare_env cars_lru5,     "lru5",     lru_Sby_name5,     lru_Sby_color5,     lru_Sby_keywords5,     &fn
	prepare_env cars_lru10,    "lru10",    lru_Sby_name10,    lru_Sby_color10,    lru_Sby_keywords10,    &fn
	prepare_env cars_lru20,    "lru20",    lru_Sby_name20,    lru_Sby_color20,    lru_Sby_keywords20,    &fn
end

ENV["REPORT_DIR"]?.try { |report_dir| Context.report_dir = report_dir }
Dir.mkdir_p Context.report_dir

ENV["MAXINDEXES"]?.try       { |it| Context.max_indexes = it.to_i }
ENV["NBRUN"]?.try            { |it| Context.nb_run      = it.to_i }
ENV["DBSIZE"]?.try           { |it| Context.to          = it.to_i }
ENV["DBSIZE_START"]?.try     { |it| Context.from        = it.to_i }
ENV["DBSIZE_INCREMENT"]?.try { |it| Context.incr        = it.to_i }
ENV["LRU_SIZE"]?.try         { |it| Context.lru_size    = it.to_u32 }

puts "REPORT_DIR:       #{Context.report_dir}"
puts "MAXINDEXES:       #{Context.max_indexes}"
puts "NBRUN:            #{Context.nb_run}"
puts "DBSIZE:           #{Context.to}"
puts "DBSIZE_START:     #{Context.from}"
puts "DBSIZE_INCREMENT: #{Context.incr}"
puts "LRU_SIZE:         #{Context.lru_size}"

if ARGV.size == 0
	puts "Usage: benchmark-cars (lru|search|add)"
	exit 0
end

case ARGV[0]
when /lru/
	bench_50_shades_of_lru
when /search/
	bench_searches
when /add/
	bench_add
else
	puts "Usage: benchmark-cars (lru|search|add)"
end