From 8ae838cc2ff9396ff00779122ac8626751942efd Mon Sep 17 00:00:00 2001
From: Nicholas Novak <34256932+NickyBoy89@users.noreply.github.com>
Date: Mon, 13 Nov 2023 16:55:09 -0800
Subject: [PATCH] feat: Added in-memory server to the testing suite

---
 storage/inmemory_server.go | 104 +++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 storage/inmemory_server.go

diff --git a/storage/inmemory_server.go b/storage/inmemory_server.go
new file mode 100644
index 0000000..c2c9dab
--- /dev/null
+++ b/storage/inmemory_server.go
@@ -0,0 +1,104 @@
+package storage
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"git.nicholasnovak.io/nnovak/spatial-db/world"
+)
+
+type InMemoryServer struct {
+	StorageDir string
+	Chunks     map[world.ChunkPos]world.ChunkData
+}
+
+func (s *InMemoryServer) SetStorageRoot(path string) {
+	s.StorageDir = path
+
+	chunkFiles, err := os.ReadDir(s.StorageDir)
+	if err != nil {
+		panic(err)
+	}
+
+	s.Chunks = make(map[world.ChunkPos]world.ChunkData)
+
+	for _, chunkFile := range chunkFiles {
+		if chunkFile.IsDir() || !strings.HasSuffix(chunkFile.Name(), ".chunk") {
+			continue
+		}
+		file, err := os.Open(filepath.Join(s.StorageDir, chunkFile.Name()))
+		if err != nil {
+			panic(err)
+		}
+
+		chunkData, err := ReadChunkFromFile(file)
+		if err != nil {
+			panic(err)
+		}
+
+		file.Close()
+
+		s.Chunks[chunkData.Pos] = chunkData
+	}
+}
+
+func (s *InMemoryServer) FetchOrCreateChunk(pos world.ChunkPos) (world.ChunkData, error) {
+	return s.Chunks[pos], nil
+}
+
+func (s *InMemoryServer) FetchChunk(pos world.ChunkPos) (world.ChunkData, error) {
+	chunkFileName := filepath.Join(s.StorageDir, pos.ToFileName())
+
+	var chunkData world.ChunkData
+
+	chunkFile, err := os.Open(chunkFileName)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return chunkData, ChunkNotFoundError
+		} else {
+			return chunkData, err
+		}
+	}
+	defer chunkFile.Close()
+
+	return ReadChunkFromFile(chunkFile)
+}
+
+// Voxel server implementation
+
+func (s *InMemoryServer) ChangeBlock(
+	worldPosition world.BlockPos,
+	targetState world.BlockID,
+) error {
+	chunk, err := s.FetchOrCreateChunk(worldPosition.ToChunkPos())
+	if err != nil {
+		return err
+	}
+
+	chunk.SectionFor(worldPosition).UpdateBlock(worldPosition, targetState)
+
+	return nil
+}
+
+func (s *InMemoryServer) ChangeBlockRange(
+	targetState world.BlockID,
+	start, end world.BlockPos,
+) error {
+	panic("ChangeBlockRange is unimplemented")
+}
+
+func (s *InMemoryServer) ReadBlockAt(pos world.BlockPos) (world.BlockID, error) {
+	chunk, err := s.FetchOrCreateChunk(pos.ToChunkPos())
+	if err != nil {
+		return world.Empty, err
+	}
+
+	return chunk.SectionFor(pos).FetchBlock(pos), nil
+}
+
+func (s *InMemoryServer) ReadChunkAt(pos world.ChunkPos) (world.ChunkData, error) {
+	return s.FetchOrCreateChunk(pos)
+}