//go:build ignore

package main

import (
	"flag"
	"fmt"
	"log"
	"monkey/internal/compiler"
	"monkey/internal/parser"
	"monkey/internal/vm"
	"os"
	"runtime"
	"runtime/pprof"
	"strings"
)

const defaultCode = `
fib := fn(n) {
	if (n < 2) {
		return n
	}
	return fib(n-1) + fib(n-2)
}

println(fib(%d))`

func checkErr(err error) {
	if err != nil {
		panic(err)
	}
}

func readFile(path string) string {
	b, err := os.ReadFile(path)
	checkErr(err)

	return string(b)
}

func fileOrDefault() (string, []string) {
	if flag.NArg() > 0 {
		log.Printf("Using %s as program input...", flag.Arg(0))
		return readFile(flag.Arg(0)), flag.Args()[1:]
	}
	return defaultCode, flag.Args()[:]
}

func main() {
	n := flag.Int("n", 35, "Set n for fib(n) [Default: 35]")
	flag.Parse()

	cpuf, err := os.Create("cpu.prof")
	checkErr(err)

	heapf, err := os.Create("heap.prof")
	checkErr(err)

	log.Printf("Using %d as n", *n)

	code, args := fileOrDefault()
	if strings.Count(code, "%d") > 0 {
		code = fmt.Sprintf(code, *n)
	}
	log.Printf("Code:\n%s\n", code)
	tree, errs := parser.Parse("<profiler>", code)
	if len(errs) > 0 {
		for _, err := range errs {
			log.Println(err)
		}
		panic("parser errors")
	}

	c := compiler.New()
	c.SetFileInfo("<profiler>", code)
	checkErr(c.Compile(tree))
	checkErr(pprof.StartCPUProfile(cpuf))
	defer pprof.StopCPUProfile()
	mvm := vm.New("<profiler>", c.Bytecode(), vm.WithContext(context.New(context.WithArgs(args))))
	checkErr(mvm.Run())
	runtime.GC()
	checkErr(pprof.WriteHeapProfile(heapf))
	log.Println("CPU Profile written to cpu.prof")
	log.Println("Heap Profile written to heap.prof")
}