// uckf creates a deeply unsatisfying word search.

package main

import (
	"flag"
	"fmt"
	"math"
)

var edgeSize = flag.Int("n", 8, "Cells per side")

type scanState int
const (
	FuckIfIKnow scanState = iota
	Fucked
	NotFucked
)

type fuckness [3][3]scanState

func main() {
	flag.Parse()
	var board [][]byte
	for i := 0; i < *edgeSize; i++ {
		fuckingRow := make([]byte, *edgeSize)
		for j := 0; j < *edgeSize; j++ {
			fuckingRow[j] = (i+j)%4
		}
		board=append(board, fuckingRow)
	}

	dump(board, "Starting position")

	evals := [][]fuckness
	for i := 0; i < *edgeSize; i++ {
		evals = append(evals, make([]fuckness, *edgeSize))
	}

	iterations := uint64(0)
	for(isStillFucked(board, evals)) {
		fuckUp(board, evals)
		iterations++
		if isPow2(iterations) {
			dump(board, fmt.Sprint("Iteration", iterations))
		}
	}

	dump(board, "Not a single fuck")
}

func charAt(board [][]byte, i, j int) byte {
	if i < 0 || j < 0 || i >= len(board) || j >= len(board[i]) {
		return 5
	}
	return board[i][j]
}

func isStillFucked(board [][]byte, evals[][]fuckness) {
	isFucked := false
	for i, row := range board {
		for j, c := range row {
			for dr := -1; dr <= 1; dr++ {
				for dc := -1; dc <= 1; dc++ {
					if dr == 0 && dc == 0 {
						continue
					}
					if evals[i][j][dr+1][dc+1] != FuckIfIKnow {
						continue
					}
					// find theoretical start of fuck
					fRow, fCol := i + int(c)*dr, j + int(c)*dr
					// evaluate fuckness
					locallyFucked := true
					for w := 0; w < 4; w++ {
						if charAt(board, i+w*dr, j+w*dc) != byte(w) {
							locallyFucked = false
							break
						}
					}
					if locallyFucked {
						// mark every letter involved as fucked
						isFucked = true
						for w := 0; w < 4; w++ {
							evals[i+w*dr][j+w*dc][dr+1][dc+1] = Fucked
						}
					} else {
						evals[i][j][dr+1][dc+1] = NotFucked
					}
				}
			}
		}
	}
	return isFucked
}

func fuckUp(board [][]byte, evals [][]fuckness) {
	
}

func dump(board [][]byte, title string) {
	fmt.Println()
	for i := 0; i < *edgeSize; i++ {
		fmt.Print("--")
	}
	fmt.Println()
	fmt.Println(title)
	fmt.Println()
	for _, row := range board {
		for _, r := range row {
			fmt.Printf("%c ", "fuck"[r])
		}
		fmt.Println()
	}
}