001 http routing

// Test: Pattern branches for HTTP routing
//
// Pattern branches like | [GET /users/:id] |> should be transformed
// into runtime dispatch based on method + path matching.

~import "$std/io"

const std = @import("std");

// Simulated request type
pub const Request = struct {
    method: []const u8,
    path: []const u8,
};

// Simulated route params
pub const RouteParams = struct {
    id: ?[]const u8 = null,
    name: ?[]const u8 = null,
};

// Event that returns a request (simulating http server)
~pub event handle { req: Request }
| response { status: u16, body: []const u8 }

// For now, we'll manually implement what the transform SHOULD generate
// This helps us understand the target behavior

~proc handle {
    // This is what a pattern branch transform would generate:
    // Parse the patterns at compile time, generate this dispatch logic

    if (std.mem.eql(u8, req.method, "GET")) {
        // Check /users/:id pattern
        if (std.mem.startsWith(u8, req.path, "/users/")) {
            const id = req.path[7..];  // Extract :id
            if (id.len > 0) {
                // Route matched: GET /users/:id
                return .{ .response = .{ .status = 200, .body = id } };
            }
        }
        // Check /health pattern
        if (std.mem.eql(u8, req.path, "/health")) {
            return .{ .response = .{ .status = 200, .body = "ok" } };
        }
    }

    if (std.mem.eql(u8, req.method, "POST")) {
        if (std.mem.eql(u8, req.path, "/users")) {
            return .{ .response = .{ .status = 201, .body = "created" } };
        }
    }

    // No match
    return .{ .response = .{ .status = 404, .body = "not found" } };
}

// Test the routing
~handle(req: .{ .method = "GET", .path = "/users/42" })
| response r |> std.io:print.ln("GET /users/42 -> {{ r.status:d }}: {{ r.body:s }}")

~handle(req: .{ .method = "GET", .path = "/health" })
| response r |> std.io:print.ln("GET /health -> {{ r.status:d }}: {{ r.body:s }}")

~handle(req: .{ .method = "POST", .path = "/users" })
| response r |> std.io:print.ln("POST /users -> {{ r.status:d }}: {{ r.body:s }}")

~handle(req: .{ .method = "DELETE", .path = "/users/1" })
| response r |> std.io:print.ln("DELETE /users/1 -> {{ r.status:d }}: {{ r.body:s }}")