From 25a7d06d4031a4288d58ef339e1326dc15b7879b Mon Sep 17 00:00:00 2001
From: Emil Lerch <emil@lerch.org>
Date: Tue, 3 Mar 2026 13:14:07 -0800
Subject: [PATCH] config.zig refactorings

---
 src/config.zig | 64 ++++++++++++++++++++++++++------------------------
 1 file changed, 33 insertions(+), 31 deletions(-)

diff --git a/src/config.zig b/src/config.zig
index 400e0a0..c2f4388 100644
--- a/src/config.zig
+++ b/src/config.zig
@@ -1,5 +1,7 @@
 const std = @import("std");
 
+const EnvMap = std.StringHashMap([]const u8);
+
 pub const Config = struct {
     twelvedata_key: ?[]const u8 = null,
     polygon_key: ?[]const u8 = null,
@@ -8,7 +10,10 @@ pub const Config = struct {
     openfigi_key: ?[]const u8 = null,
     cache_dir: []const u8,
     allocator: ?std.mem.Allocator = null,
+    /// Raw .env file contents (keys/values in env_map point into this).
     env_buf: ?[]const u8 = null,
+    /// Parsed KEY=VALUE pairs from .env file.
+    env_map: ?EnvMap = null,
 
     pub fn fromEnv(allocator: std.mem.Allocator) Config {
         var self = Config{
@@ -16,8 +21,11 @@ pub const Config = struct {
             .allocator = allocator,
         };
 
-        // Try loading .env file from the project directory or home directory
-        self.env_buf = loadEnvFile(allocator);
+        // Try loading .env file from the current working directory
+        self.env_buf = std.fs.cwd().readFileAlloc(allocator, ".env", 4096) catch null;
+        if (self.env_buf) |buf| {
+            self.env_map = parseEnvFile(allocator, buf);
+        }
 
         self.twelvedata_key = self.resolve("TWELVEDATA_API_KEY");
         self.polygon_key = self.resolve("POLYGON_API_KEY");
@@ -27,8 +35,14 @@ pub const Config = struct {
 
         const env_cache = self.resolve("ZFIN_CACHE_DIR");
         self.cache_dir = env_cache orelse blk: {
-            const home = std.posix.getenv("HOME") orelse "/tmp";
-            break :blk std.fs.path.join(allocator, &.{ home, ".cache", "zfin" }) catch @panic("OOM");
+            // XDG Base Directory: $XDG_CACHE_HOME/zfin, falling back to $HOME/.cache/zfin
+            const base = std.posix.getenv("XDG_CACHE_HOME") orelse fallback: {
+                const home = std.posix.getenv("HOME") orelse "/tmp";
+                break :fallback std.fs.path.join(allocator, &.{ home, ".cache" }) catch @panic("OOM");
+            };
+            const base_allocated = std.posix.getenv("XDG_CACHE_HOME") == null;
+            defer if (base_allocated) allocator.free(base);
+            break :blk std.fs.path.join(allocator, &.{ base, "zfin" }) catch @panic("OOM");
         };
 
         return self;
@@ -36,8 +50,13 @@ pub const Config = struct {
 
     pub fn deinit(self: *Config) void {
         if (self.allocator) |a| {
-            // Check if cache_dir was allocated (not from env/envfile) BEFORE freeing env_buf
+            // cache_dir is allocated (via path.join) unless ZFIN_CACHE_DIR was set directly.
+            // Check BEFORE freeing env_map/env_buf, since resolve() reads from them.
             const cache_dir_from_env = self.resolve("ZFIN_CACHE_DIR") != null;
+            if (self.env_map) |*m| {
+                var map = m.*;
+                map.deinit();
+            }
             if (self.env_buf) |buf| a.free(buf);
             if (!cache_dir_from_env) {
                 a.free(self.cache_dir);
@@ -55,41 +74,24 @@ pub const Config = struct {
     /// Look up a key: environment variable first, then .env file fallback.
     fn resolve(self: Config, key: []const u8) ?[]const u8 {
         if (std.posix.getenv(key)) |v| return v;
-        return envFileGet(self.env_buf, key);
+        if (self.env_map) |m| return m.get(key);
+        return null;
     }
 };
 
-/// Parse a KEY=VALUE line from .env content. Returns value for the given key.
-fn envFileGet(buf: ?[]const u8, key: []const u8) ?[]const u8 {
-    const data = buf orelse return null;
+/// Parse all KEY=VALUE pairs from .env content into a HashMap.
+/// Values are slices into the original buffer (no extra allocations per entry).
+fn parseEnvFile(allocator: std.mem.Allocator, data: []const u8) ?EnvMap {
+    var map = EnvMap.init(allocator);
     var iter = std.mem.splitScalar(u8, data, '\n');
     while (iter.next()) |line| {
         const trimmed = std.mem.trim(u8, line, &std.ascii.whitespace);
         if (trimmed.len == 0 or trimmed[0] == '#') continue;
         if (std.mem.indexOfScalar(u8, trimmed, '=')) |eq| {
             const k = std.mem.trim(u8, trimmed[0..eq], &std.ascii.whitespace);
-            if (std.mem.eql(u8, k, key)) {
-                return std.mem.trim(u8, trimmed[eq + 1 ..], &std.ascii.whitespace);
-            }
+            const v = std.mem.trim(u8, trimmed[eq + 1 ..], &std.ascii.whitespace);
+            map.put(k, v) catch return null;
         }
     }
-    return null;
-}
-
-/// Try to load .env from the executable's directory, then cwd.
-fn loadEnvFile(allocator: std.mem.Allocator) ?[]const u8 {
-    // Try relative to the executable
-    const exe_dir = std.fs.selfExeDirPathAlloc(allocator) catch null;
-    defer if (exe_dir) |d| allocator.free(d);
-
-    if (exe_dir) |dir| {
-        const path = std.fs.path.join(allocator, &.{ dir, "..", ".env" }) catch null;
-        defer if (path) |p| allocator.free(p);
-        if (path) |p| {
-            if (std.fs.cwd().readFileAlloc(allocator, p, 4096)) |data| return data else |_| {}
-        }
-    }
-
-    // Try cwd
-    return std.fs.cwd().readFileAlloc(allocator, ".env", 4096) catch null;
+    return map;
 }