const std = @import("std");

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

    const upstream = b.dependency("alsa-lib", .{});

    // Create config header matching autotools output
    const config = b.addConfigHeader(.{
        .style = .blank,
        .include_path = "config.h",
    }, .{
        .PACKAGE_NAME = "alsa-lib",
        .VERSION = "1.2.14",
        .HAVE_USELOCALE = 1,
        .HAVE_EACCESS = 1,
        .HAVE_ENDIAN_H = 1,
        .HAVE_SYS_SHM_H = 1,
        .HAVE_MALLOC_H = 1,
        .HAVE_LFS = 1,
        .HAVE_LIBDL = 1,  // Match native build
        // .PIC = 0,  // Remove PIC entirely to enable builtin symbols
        .BUILD_PCM = "1",
        .BUILD_MIXER = "1",
        .BUILD_HWDEP = "1",
        .ENABLE_STATIC = 1,  // Match --enable-static=yes
        .ENABLE_SHARED = 0,  // Match --enable-shared=no
        .ALSA_DEVICE_DIRECTORY = "/dev/snd/",
        .ALSA_CONFIG_DIR = "/usr/share/alsa",
        .ALSA_PLUGIN_DIR = "/usr/lib/alsa-lib",
        .SND_MAX_CARDS = 32,
        .BUILD_PCM_PLUGIN_ADPCM = "1",
        .BUILD_PCM_PLUGIN_ALAW = "1",
        .BUILD_PCM_PLUGIN_IEC958 = "1",
        .BUILD_PCM_PLUGIN_LFLOAT = "1",
        .BUILD_PCM_PLUGIN_MMAP_EMUL = "1",
        .BUILD_PCM_PLUGIN_MULAW = "1",
        .BUILD_PCM_PLUGIN_RATE = "1",
        .BUILD_PCM_PLUGIN_ROUTE = "1",
        .__SYMBOL_PREFIX = "",
        ._GNU_SOURCE = 1,
        .HAVE_GNU_LD = 1,
        .HAVE_ELF = 1,
        .HAVE_ASM_PREVIOUS_DIRECTIVE = 1,
        .BUILD_STATIC = 1,
        .BUILD_PCM_PLUGIN_HW = 1,
        .SND_PCM_BUILTIN = 1,
    });

    // Create version.h
    const version_h = b.addWriteFiles();
    _ = version_h.add("version.h",
        \\/*
        \\ *  version.h
        \\ */
        \\
        \\#define SND_LIB_MAJOR 1 /**< major number of library version */
        \\#define SND_LIB_MINOR 2 /**< minor number of library version */
        \\#define SND_LIB_SUBMINOR 14 /**< subminor number of library version */
        \\#define SND_LIB_EXTRAVER 1000000 /**< extra version number, used mainly for betas */
        \\/** library version */
        \\#define SND_LIB_VER(maj, min, sub) (((maj)<<16)|((min)<<8)|(sub))
        \\#define SND_LIB_VERSION SND_LIB_VER(SND_LIB_MAJOR, SND_LIB_MINOR, SND_LIB_SUBMINOR)
        \\/** library version (string) */
        \\#define SND_LIB_VERSION_STR "1.2.14"
        \\
    );

    // Generate asoundlib.h
    const asoundlib_h = b.addWriteFiles();
    _ = asoundlib_h.add("asoundlib.h",
        \\/*
        \\ *  ALSA library - main header file
        \\ */
        \\
        \\#ifndef __ALSA_ASOUNDLIB_H
        \\#define __ALSA_ASOUNDLIB_H
        \\
        \\#include <stdio.h>
        \\#include <stdlib.h>
        \\#include <string.h>
        \\#include <fcntl.h>
        \\#include <assert.h>
        \\#include <endian.h>
        \\#include <sys/poll.h>
        \\#include <errno.h>
        \\#include <stdint.h>
        \\#include <sys/types.h>
        \\#include <unistd.h>
        \\
        \\#include <alsa/asoundef.h>
        \\#include <alsa/version.h>
        \\#include <alsa/global.h>
        \\#include <alsa/input.h>
        \\#include <alsa/output.h>
        \\#include <alsa/error.h>
        \\#include <alsa/conf.h>
        \\#include <alsa/control.h>
        \\#include <alsa/pcm.h>
        \\
        \\#endif /* __ALSA_ASOUNDLIB_H */
        \\
    );

    const lib = b.addLibrary(.{
        .name = "asound",
        .linkage = .static,
        .root_module = b.createModule(.{
            .target = target,
            .optimize = optimize,
            .link_libc = true,
        }),
    });

    lib.addConfigHeader(config);
    lib.addIncludePath(upstream.path("include"));
    lib.addIncludePath(upstream.path("src/pcm"));  // For pcm_rate.h etc
    lib.addIncludePath(b.path("."));  // For our pcm_symbols_list.c
    lib.addIncludePath(version_h.getDirectory());
    lib.addIncludePath(asoundlib_h.getDirectory());

    // Create alsa as symlink for the include directory. Not sure why upstream
    // does this, but since we're not using their scripts, we need to do that
    // as well
    const create_symlink = b.addSystemCommand(&.{ "sh", "-c", "rm -f alsa; ln -sf . alsa" });
    create_symlink.setCwd(upstream.path("include"));
    lib.step.dependOn(&create_symlink.step);

    lib.addCSourceFiles(.{
        .root = upstream.path(""),
        .files = &.{
            "src/conf.c",
            "src/confeval.c",
            "src/confmisc.c",
            "src/input.c",
            "src/output.c",
            "src/async.c",
            "src/error.c",
            "src/dlmisc.c",
            "src/socket.c",
            "src/shmarea.c",
            "src/userfile.c",
            "src/names.c",
            "src/control/control.c",
            "src/control/control_hw.c",
            "src/control/cards.c",
            "src/control/namehint.c",
            "src/control/hcontrol.c",
            "src/control/tlv.c",
            "src/control/setup.c",
            "src/control/ctlparse.c",
            "src/control/eld.c",
            "src/control/control_empty.c",  // Empty control
            "src/pcm/pcm.c",
            "src/pcm/pcm_hw.c",
            "src/pcm/pcm_params.c",
            "src/pcm/pcm_misc.c",
            "src/pcm/pcm_mmap.c",
            "src/pcm/pcm_generic.c",
            "src/pcm/pcm_simple.c",
            "src/pcm/pcm_plug.c",
            "src/pcm/mask.c",
            "src/pcm/interval.c",
            // Core PCM plugins - must match native build
            "src/pcm/pcm_copy.c",
            "src/pcm/pcm_linear.c",
            "src/pcm/pcm_null.c",
            "src/pcm/pcm_empty.c",
            "src/pcm/pcm_adpcm.c",
            "src/pcm/pcm_alaw.c",
            "src/pcm/pcm_mulaw.c",
            "src/pcm/pcm_iec958.c",
            "src/pcm/pcm_lfloat.c",
            "src/pcm/pcm_mmap_emul.c",
            "src/pcm/pcm_route.c",
            "src/pcm/pcm_plugin.c",  // Plugin support functions
            "src/pcm/pcm_symbols.c",  // Builtin plugin registration
            "src/control/control_symbols.c",  // Control symbols
            "src/timer/timer_symbols.c",  // Timer symbols
            "src/timer/timer.c",
            "src/timer/timer_hw.c",
            "src/timer/timer_query.c",
            "src/timer/timer_query_hw.c",
        },
        .flags = &.{
            "-D_GNU_SOURCE",
            "-DALSA_LIBRARY_BUILD",
            "-DALSA_STATIC",
            "-DBUILD_STATIC_ONLY",
            "-UPIC",  // Explicitly undefine PIC to enable builtin symbols
        },
    });

    lib.installHeadersDirectory(upstream.path("include"), "alsa", .{
        .include_extensions = &.{
            "asoundef.h",
            "version.h",
            "global.h",
            "input.h",
            "output.h",
            "error.h",
            "conf.h",
            "control.h",
            "pcm.h",
        },
    });

    // Install generated asoundlib.h and version.h
    lib.installHeader(asoundlib_h.getDirectory().path(b, "asoundlib.h"), "alsa/asoundlib.h");
    lib.installHeader(version_h.getDirectory().path(b, "version.h"), "alsa/version.h");

    b.installArtifact(lib);
}