const std = @import("std");

pub fn build(b: *std.Build) !void {
    // Default to aarch64-linux for Lambda Graviton deployment
    const target = b.standardTargetOptions(.{
        .default_target = .{
            .cpu_arch = .aarch64,
            .os_tag = .linux,
        },
    });
    const optimize = b.standardOptimizeOption(.{});

    // Get lambda-zig dependency
    const lambda_zig_dep = b.dependency("lambda_zig", .{
        .target = target,
        .optimize = optimize,
    });

    // Get controlr dependency for rinnai module
    const controlr_dep = b.dependency("controlr", .{
        .target = target,
        .optimize = optimize,
    });

    // Create the main module
    const main_module = b.createModule(.{
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
    });

    // Add lambda_runtime import
    main_module.addImport("lambda_runtime", lambda_zig_dep.module("lambda_runtime"));
    // Add rinnai import from controlr
    main_module.addImport("rinnai", controlr_dep.module("rinnai"));

    // Create executable
    const exe = b.addExecutable(.{
        .name = "bootstrap", // Lambda requires the executable to be named "bootstrap"
        .root_module = main_module,
    });

    b.installArtifact(exe);

    // Create a step to package for Lambda
    const package_step = b.step("package", "Package for AWS Lambda (arm64) deployment");

    // After installing, create a zip
    const install_step = b.getInstallStep();

    // Add a system command to create zip (requires zip to be installed)
    const zip_cmd = b.addSystemCommand(&.{
        "zip", "-j", "function.zip", "zig-out/bin/bootstrap",
    });
    zip_cmd.step.dependOn(install_step);
    package_step.dependOn(&zip_cmd.step);

    // Test step - reuses the same target query, tests run via emulation or on native arm64
    const test_module = b.createModule(.{
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
    });
    test_module.addImport("lambda_runtime", lambda_zig_dep.module("lambda_runtime"));
    test_module.addImport("rinnai", controlr_dep.module("rinnai"));

    const main_tests = b.addTest(.{
        .name = "test",
        .root_module = test_module,
    });

    const run_main_tests = b.addRunArtifact(main_tests);
    const test_step = b.step("test", "Run unit tests");
    test_step.dependOn(&run_main_tests.step);
}