From 5ca089afb4a96d90e610df4f1aaaa011b67cc5f2 Mon Sep 17 00:00:00 2001
From: Davide Oddone <davide@oddone.dev>
Date: Tue, 12 Dec 2023 21:58:03 +0100
Subject: [PATCH] WIP day10

---
 day10/maze.go | 76 ++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 72 insertions(+), 4 deletions(-)

diff --git a/day10/maze.go b/day10/maze.go
index d94bac0..a5b01b2 100644
--- a/day10/maze.go
+++ b/day10/maze.go
@@ -3,15 +3,28 @@ package main
 import (
 	"bufio"
 	"fmt"
+	"log"
 	"os"
 	"sync"
 	"time"
 )
 
 // Parallel code, global vars
-type Nodes struct {
-	mu       sync.Mutex
-	variable int
+type Maze struct {
+	mu        sync.Mutex
+	direction [][]rune
+	steps     int
+}
+
+var mapDirections = map[rune]int8{
+	'|': 0, // Vertical
+	'-': 1, // Horizontal
+	'L': 2, // North to East
+	'J': 3, // North to West
+	'7': 4, // South to West
+	'F': 5, // South to East
+	'.': 6, // Ground
+	'S': 7, // Start
 }
 
 func check(e error) {
@@ -34,15 +47,70 @@ func timer(name string) func() {
 	}
 }
 
+func (mz *Maze) ChooseFirstDirection(startPoint [2]int) [2]int {
+	// For the first step, we don't care about directions, we only need a tile
+	// were we can step on. E.g., if we have a J North of S we CAN'T go. A 7 would
+	// be OK.
+	x := startPoint[0]
+	y := startPoint[1]
+	// If x - 1 (going west), only 1, 2, 5 allowed
+	temp := mapDirections[mz.direction[x-1][y]]
+	if temp == 1 || temp == 2 || temp == 5 {
+    	PrintAndWait("We go West boi")
+    // If x + 1 (going east), only 1, 3, 4 allowed
+	} else if temp := mapDirections[mz.direction[x+1][y]]; temp == 1 || temp == 3 || temp == 4 {
+    	PrintAndWait("We go East boi")
+  	// If y - 1 (going north), only 0, 4, 5 allowed
+	} else if temp := mapDirections[mz.direction[x][y-1]]; temp == 0 || temp == 4 || temp == 5 {
+    	PrintAndWait("We go North boi")
+	} else {
+    	log.Fatal("How is this even possible..?")
+	}
+}
+
+func (mz *Maze) FindPath(startPoint [2]int) {
+    nextCheck := startPoint
+    nextCheck = mz.ChooseFirstDirection(nextCheck)
+}
+
 func main() {
-	file, err := os.Open("./inputs")
+	if len(os.Args) != 2 {
+		fmt.Println("Must provide exactly one argument. It must be a file.")
+		log.Fatal("NOW I WILL SCREAM AND DIE.")
+	}
+	file, err := os.Open(os.Args[1])
 	check(err)
 	defer file.Close()
 
 	lines := make([]string, 0)
 
+	mz := Maze{}
+
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
 		lines = append(lines, scanner.Text())
 	}
+
+	numColumns := len(lines)
+
+	mz.direction = make([][]rune, numColumns)
+	// Populate the array of directions
+	for i := 0; i < numColumns; i++ {
+		for j := 0; j < len(lines[i]); j++ {
+			mz.direction[i] = append(mz.direction[i], rune(lines[i][j]))
+		}
+	}
+	var startPoint [2]int
+	// Search for the starting point
+	for i := 0; i < numColumns; i++ {
+		for j := 0; j < len(lines[i]); j++ {
+			if mapDirections[mz.direction[i][j]] == 7 {
+				startPoint[0] = i
+				startPoint[1] = j
+			}
+		}
+	}
+	// Going west:  x - 1 | Going east:  x + 1
+	// Going north: y - 1 | Going south: y + 1
+	mz.FindPath(startPoint)
 }