phase 2 done

1 files changed, 30 insertions, 0 deletions

diff --git a/libpanto/src/provider.zig b/libpanto/src/provider.zig
index 16c3dd6..6d97bb7 100644
--- a/libpanto/src/provider.zig
+++ b/libpanto/src/provider.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const conversation = @import("conversation.zig");
+const config_mod = @import("config.zig");
 
 pub const ContentBlockType = enum {
     Text,
@@ -73,6 +74,35 @@ pub const Provider = struct {
     ptr: *anyopaque,
     vtable: *const ProviderVTable,
 
+    /// Construct the concrete provider implementation that matches `cfg`'s
+    /// API style, heap-allocate it, and return a `Provider` interface bound
+    /// to it. `deinit` tears down the impl and frees the allocation.
+    ///
+    /// The concrete provider types (`OpenAIChatProvider`, etc.) are
+    /// implementation details; callers interact only with this interface.
+    pub fn init(
+        allocator: std.mem.Allocator,
+        io: std.Io,
+        cfg: config_mod.Config,
+    ) !Provider {
+        // Imported lazily to break the circular module graph:
+        // provider.zig <- provider_openai_chat.zig <- provider.zig.
+        const provider_openai_chat = @import("provider_openai_chat.zig");
+        const provider_anthropic_messages = @import("provider_anthropic_messages.zig");
+        switch (cfg) {
+            .openai_chat => |c| {
+                const impl = try allocator.create(provider_openai_chat.OpenAIChatProvider);
+                impl.* = provider_openai_chat.OpenAIChatProvider.init(allocator, io, c);
+                return impl.provider();
+            },
+            .anthropic_messages => |c| {
+                const impl = try allocator.create(provider_anthropic_messages.AnthropicMessagesProvider);
+                impl.* = provider_anthropic_messages.AnthropicMessagesProvider.init(allocator, io, c);
+                return impl.provider();
+            },
+        }
+    }
+
     pub fn streamStep(self: Provider, conv: *conversation.Conversation, receiver: *Receiver) anyerror!void {
         return self.vtable.streamStep(self.ptr, conv, receiver);
     }