From 58d09b1f7e23174eae1da30193097ab99217787b Mon Sep 17 00:00:00 2001
From: Emil Lerch <emil@lerch.org>
Date: Thu, 18 Dec 2025 11:23:38 -0800
Subject: [PATCH] AI: download geoip on startup if it does not exist

---
 zig/src/location/geolite_downloader.zig | 72 +++++++++++++++++++++++++
 zig/src/main.zig                        |  4 ++
 2 files changed, 76 insertions(+)
 create mode 100644 zig/src/location/geolite_downloader.zig

diff --git a/zig/src/location/geolite_downloader.zig b/zig/src/location/geolite_downloader.zig
new file mode 100644
index 0000000..f4aaf2c
--- /dev/null
+++ b/zig/src/location/geolite_downloader.zig
@@ -0,0 +1,72 @@
+const std = @import("std");
+
+pub fn ensureDatabase(allocator: std.mem.Allocator, path: []const u8) !void {
+    std.fs.cwd().access(path, .{}) catch {
+        std.log.info("GeoLite2 database not found at {s}, downloading...", .{path});
+        try downloadDatabase(allocator, path);
+        std.log.info("GeoLite2 database downloaded successfully", .{});
+        return;
+    };
+}
+
+fn downloadDatabase(allocator: std.mem.Allocator, path: []const u8) !void {
+    const latest_url = try getLatestReleaseUrl(allocator);
+    defer allocator.free(latest_url);
+
+    var client: std.http.Client = .{ .allocator = allocator };
+    defer client.deinit();
+
+    const uri = try std.Uri.parse(latest_url);
+    const response_buf = try allocator.alloc(u8, 64 * 1024 * 1024);
+    defer allocator.free(response_buf);
+
+    var writer = std.Io.Writer.fixed(response_buf);
+    const result = try client.fetch(.{
+        .location = .{ .uri = uri },
+        .method = .GET,
+        .response_writer = &writer,
+    });
+
+    if (result.status != .ok) return error.DownloadFailed;
+
+    const file = try std.fs.cwd().createFile(path, .{});
+    defer file.close();
+    try file.writeAll(response_buf[0..writer.end]);
+}
+
+fn getLatestReleaseUrl(allocator: std.mem.Allocator) ![]const u8 {
+    var client: std.http.Client = .{ .allocator = allocator };
+    defer client.deinit();
+
+    const api_url = "https://api.github.com/repos/P3TERX/GeoLite.mmdb/releases/latest";
+    const uri = try std.Uri.parse(api_url);
+
+    const response_buf = try allocator.alloc(u8, 1024 * 1024);
+    defer allocator.free(response_buf);
+
+    var writer = std.Io.Writer.fixed(response_buf);
+    const result = try client.fetch(.{
+        .location = .{ .uri = uri },
+        .method = .GET,
+        .response_writer = &writer,
+        .extra_headers = &.{
+            .{ .name = "User-Agent", .value = "wttr.in" },
+        },
+    });
+
+    if (result.status != .ok) return error.ApiFailed;
+
+    const json_data = response_buf[0..writer.end];
+    const parsed = try std.json.parseFromSlice(std.json.Value, allocator, json_data, .{});
+    defer parsed.deinit();
+
+    const assets = parsed.value.object.get("assets") orelse return error.NoAssets;
+    for (assets.array.items) |asset| {
+        const name = asset.object.get("name") orelse continue;
+        if (std.mem.eql(u8, name.string, "GeoLite2-City.mmdb")) {
+            const url = asset.object.get("browser_download_url") orelse return error.NoDownloadUrl;
+            return allocator.dupe(u8, url.string);
+        }
+    }
+    return error.DatabaseNotFound;
+}
diff --git a/zig/src/main.zig b/zig/src/main.zig
index c39e3e8..3b922bc 100644
--- a/zig/src/main.zig
+++ b/zig/src/main.zig
@@ -9,6 +9,7 @@ const GeoIP = @import("location/geoip.zig").GeoIP;
 const GeoCache = @import("location/geocache.zig").GeoCache;
 const AirportDB = @import("location/airports.zig").AirportDB;
 const Resolver = @import("location/resolver.zig").Resolver;
+const geolite_downloader = @import("location/geolite_downloader.zig");
 
 pub const std_options: std.Options = .{
     .log_level = .info,
@@ -40,6 +41,9 @@ pub fn main() !void {
     }
     try stdout.flush();
 
+    // Ensure GeoLite2 database exists
+    try geolite_downloader.ensureDatabase(allocator, cfg.geolite_path);
+
     // Initialize GeoIP database
     var geoip = GeoIP.init(cfg.geolite_path) catch |err| {
         std.log.warn("Failed to load GeoIP database: {}", .{err});