// Targets:
// - default: ml (ReleaseSmall)
// - dev:     ml-dev (Debug)
// - prod:    ml (ReleaseSmall) -> zig-out/prod
// - release: ml-release (ReleaseFast) -> zig-out/release
// - cross:   ml-* per platform -> zig-out/cross

const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{ .preferred_optimize_mode = .ReleaseSmall });

    // Common executable configuration
    // Default build optimizes for small binary size (~200KB after strip)
    const exe = b.addExecutable(.{
        .name = "ml",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),
            .target = target,
            .optimize = optimize,
        }),
    });

    // Embed rsync binary if available
    const embed_rsync = b.option(bool, "embed-rsync", "Embed rsync binary in CLI") orelse false;
    if (embed_rsync) {
        // This would embed the actual rsync binary
        // For now, we'll use the wrapper approach
        exe.root_module.addCMacro("EMBED_RSYNC", "1");
    }

    b.installArtifact(exe);

    // Default run command
    const run_cmd = b.addRunArtifact(exe);
    run_cmd.step.dependOn(b.getInstallStep());
    if (b.args) |args| {
        run_cmd.addArgs(args);
    }
    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);

    // === Development Build ===
    // Fast build with debug info for development
    const dev_exe = b.addExecutable(.{
        .name = "ml-dev",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),
            .target = b.resolveTargetQuery(.{}), // Use host target
            .optimize = .Debug,
        }),
    });

    const dev_install = b.addInstallArtifact(dev_exe, .{
        .dest_dir = .{ .override = .{ .custom = "dev" } },
    });
    const dev_step = b.step("dev", "Build development version (fast compilation, debug info)");
    dev_step.dependOn(&dev_install.step);

    // === Production Build ===
    // Optimized for size and speed
    const prod_exe = b.addExecutable(.{
        .name = "ml",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),
            .target = target,
            .optimize = .ReleaseSmall, // Optimize for small binary size
        }),
    });

    const prod_install = b.addInstallArtifact(prod_exe, .{
        .dest_dir = .{ .override = .{ .custom = "prod" } },
    });
    const prod_step = b.step("prod", "Build production version (optimized for size and speed)");
    prod_step.dependOn(&prod_install.step);

    // === Release Build ===
    // Fully optimized for performance
    const release_exe = b.addExecutable(.{
        .name = "ml-release",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),
            .target = target,
            .optimize = .ReleaseFast, // Optimize for speed
        }),
    });

    const release_install = b.addInstallArtifact(release_exe, .{
        .dest_dir = .{ .override = .{ .custom = "release" } },
    });
    const release_step = b.step("release", "Build release version (optimized for performance)");
    release_step.dependOn(&release_install.step);

    // === Cross-Platform Builds ===
    // Build for common platforms with descriptive binary names
    const cross_targets = [_]struct {
        query: std.Target.Query,
        name: []const u8,
    }{
        .{ .query = .{ .cpu_arch = .x86_64, .os_tag = .linux }, .name = "ml-linux-x86_64" },
        .{ .query = .{ .cpu_arch = .x86_64, .os_tag = .linux, .abi = .musl }, .name = "ml-linux-musl-x86_64" },
        .{ .query = .{ .cpu_arch = .x86_64, .os_tag = .macos }, .name = "ml-macos-x86_64" },
        .{ .query = .{ .cpu_arch = .aarch64, .os_tag = .macos }, .name = "ml-macos-aarch64" },
    };

    const cross_step = b.step("cross", "Build cross-platform binaries");

    for (cross_targets) |ct| {
        const cross_target = b.resolveTargetQuery(ct.query);
        const cross_exe = b.addExecutable(.{
            .name = ct.name,
            .root_module = b.createModule(.{
                .root_source_file = b.path("src/main.zig"),
                .target = cross_target,
                .optimize = .ReleaseSmall,
            }),
        });

        const cross_install = b.addInstallArtifact(cross_exe, .{
            .dest_dir = .{ .override = .{ .custom = "cross" } },
        });
        cross_step.dependOn(&cross_install.step);
    }

    // === Clean Step ===
    const clean_step = b.step("clean", "Clean build artifacts");
    const clean_cmd = b.addSystemCommand(&[_][]const u8{
        "rm",      "-rf",
        "zig-out", ".zig-cache",
    });
    clean_step.dependOn(&clean_cmd.step);

    // === Install Step ===
    // Install binary to system PATH
    const install_step = b.step("install-system", "Install binary to /usr/local/bin");
    const install_cmd = b.addSystemCommand(&[_][]const u8{
        "sudo", "cp", "zig-out/bin/ml", "/usr/local/bin/",
    });
    install_step.dependOn(&install_cmd.step);

    // === Size Check ===
    // Show binary sizes for different builds
    const size_step = b.step("size", "Show binary sizes");
    const size_cmd = b.addSystemCommand(&[_][]const u8{
        "sh", "-c",
        "if [ -d zig-out/bin ]; then echo 'zig-out/bin contents:'; ls -lh zig-out/bin/; fi; " ++
            "if [ -d zig-out/prod ]; then echo '\nzig-out/prod contents:'; ls -lh zig-out/prod/; fi; " ++
            "if [ -d zig-out/release ]; then echo '\nzig-out/release contents:'; ls -lh zig-out/release/; fi; " ++
            "if [ -d zig-out/cross ]; then echo '\nzig-out/cross contents:'; ls -lh zig-out/cross/; fi; " ++
            "if [ ! -d zig-out/bin ] && [ ! -d zig-out/prod ] && [ ! -d zig-out/release ] && [ ! -d zig-out/cross ]; then " ++
            "echo 'No CLI binaries found. Run zig build (default), zig build dev, zig build prod, or zig build release first.'; fi",
    });
    size_step.dependOn(&size_cmd.step);

    // Test step
    const source_module = b.createModule(.{
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
    });
    const test_module = b.createModule(.{
        .root_source_file = b.path("tests/main_test.zig"),
        .target = target,
        .optimize = optimize,
    });
    test_module.addImport("src", source_module);

    const exe_tests = b.addTest(.{
        .root_module = test_module,
    });
    const run_exe_tests = b.addRunArtifact(exe_tests);
    const test_step = b.step("test", "Run unit tests");
    test_step.dependOn(&run_exe_tests.step);
}