From e58fd44ec0aaafe245e5c2d694690459eb6129b8 Mon Sep 17 00:00:00 2001
From: iddev5 <ayushbardhan5@gmail.com>
Date: Mon, 20 Jun 2022 13:11:12 +0530
Subject: [PATCH] mach: Implement basic resource loading system

Curently no real management has been implemented. It just loads the
resource from the list of paths present and provides the raw data from
it.
---
 src/main.zig                     |  1 +
 src/resource/ResourceManager.zig | 64 ++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 src/resource/ResourceManager.zig

diff --git a/src/main.zig b/src/main.zig
index cd3f80d6..686a133d 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -2,3 +2,4 @@ pub usingnamespace @import("structs.zig");
 pub usingnamespace @import("enums.zig");
 pub const Engine = @import("Engine.zig");
 pub const Timer = @import("Timer.zig");
+pub const ResourceManager = @import("resource/ResourceManager.zig");
diff --git a/src/resource/ResourceManager.zig b/src/resource/ResourceManager.zig
new file mode 100644
index 00000000..cc4e633e
--- /dev/null
+++ b/src/resource/ResourceManager.zig
@@ -0,0 +1,64 @@
+const std = @import("std");
+const uri_parser = @import("uri_parser.zig");
+
+const ResourceManager = @This();
+
+allocator: std.mem.Allocator,
+paths: []const []const u8,
+resource_types: []const ResourceType,
+resources: std.ArrayListUnmanaged(Resource) = .{},
+cwd: std.fs.Dir,
+
+pub fn init(allocator: std.mem.Allocator, paths: []const []const u8, resource_types: []const ResourceType) !ResourceManager {
+    var cwd = try std.fs.openDirAbsolute(try std.fs.selfExeDirPathAlloc(allocator), .{});
+    errdefer cwd.close();
+
+    return ResourceManager{
+        .allocator = allocator,
+        .paths = paths,
+        .resource_types = resource_types,
+        .cwd = cwd,
+    };
+}
+
+pub const ResourceType = struct {
+    name: []const u8,
+    load: fn (context: *anyopaque, mem: []const u8) error{ InvalidResource, CorruptData }!*anyopaque,
+    unload: fn (context: *anyopaque, resource: *anyopaque) void,
+};
+
+pub fn getResource(self: *ResourceManager, uri: []const u8) !Resource {
+    var file: ?std.fs.File = null;
+    const uri_data = try uri_parser.parseUri(uri);
+
+    for (self.paths) |path| {
+        var dir = try self.cwd.openDir(path, .{});
+        defer dir.close();
+
+        file = dir.openFile(uri_data.path, .{}) catch |err| switch (err) {
+            error.FileNotFound => continue,
+            else => return err,
+        };
+        errdefer file.deinit();
+    }
+
+    if (file) |f| {
+        var data = try f.reader().readAllAlloc(self.allocator, std.math.maxInt(usize));
+        errdefer data.deinit();
+
+        return Resource{ .resource = @ptrCast(*anyopaque, &data.ptr), .size = data.len };
+    }
+
+    return error.ResourceNotFound;
+}
+
+pub const Resource = struct {
+    resource: *anyopaque,
+    size: u64,
+
+    // Returns the raw data, which you can use in any ways. Internally it is stored
+    // as an *anyopaque
+    pub fn getData(res: *const Resource, comptime T: type) *T {
+        return @ptrCast(*T, @alignCast(std.meta.alignment(*T), res.resource));
+    }
+};