const std = @import("std");
const fs = std.fs;
const builtin = @import("builtin");
const common = @import("../build_common.zig");

const mkvar_thread_version = "3.0.1";
const mkvar_thread_zip_file = "libthread" ++ mkvar_thread_version ++ ".zip";
const mkvar_thread_vfs_root = "libthread.vfs";
const mkvar_thread_vfs_path = mkvar_thread_vfs_root ++ "/thread_library";

const mkvar_pkg_lib_file = "tcl9thread301.dll";

// Although this function looks imperative, note that its job is to
// declaratively construct a build graph that will be executed by an external
// runner.
//pub fn build(b: *std.Build) !void {}
pub fn build_tclthread(comptime tcldir: []const u8, comptime subdir: []const u8, b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, stublib: *std.Build.Step.Compile) !*std.Build.Step.Compile {
    const wrapfilecmd = b.addExecutable(.{
        .name = "wrapfiletofile",
        .root_module = b.createModule(.{
            .root_source_file = b.path("tools/wrapfiletofile.zig"),
            .target = b.graph.host,
        }),
    });
    const uuidcmd_step = b.addRunArtifact(wrapfilecmd);
    uuidcmd_step.addArgs(&.{
        "-prefix",
        "#define THREAD_VERSION_UUID \\",
        "-prefixnl",
        "1",
        "-input",
    });
    uuidcmd_step.addFileArg(b.path(subdir ++ "/manifest.uuid"));
    uuidcmd_step.addArg("-output");
    const threaduuid_file = uuidcmd_step.addOutputFileArg("threadUuid.h");

    //var interp: []const []const u8 = undefined;
    ////note we determine the interp based on the machine running the build - not the target
    //if (builtin.os.tag == .windows) {
    //    interp =  &.{
    //        "wrapfiletofile.cmd",
    //    };
    //} else {
    //    interp = &.{
    //        "bash", //explicitly use bash. Sometimes sh is linked to some other shell such as zsh, or dash (e.g debian,ubuntu) which don't understand substitution syntax like bash and ordinary posix sh do
    //        "wrapfiletofile.cmd",
    //    };
    //}
    //const uuid_cmd = b.addSystemCommand(interp);
    //uuid_cmd.addArgs(&.{
    //    "-prefix",
    //    "#define THREAD_VERSION_UUID \\",
    //    "-prefixnl",
    //    "1",
    //    "-input",
    //});
    ////uuid_cmd.addFileArg(.{ .path = b.pathJoin(&.{ b.pathFromRoot(""), "..", "tcl" ++ tcl_version, "manifest.uuid" }) });
    //uuid_cmd.addFileArg(b.path(subdir ++ "/manifest.Uuid"));
    //uuid_cmd.addArg("-output");
    //const tcluuid_file1 = uuid_cmd.addOutputFileArg("threadUuid.h");

    //(G-102: the former addUpdateSourceFiles copy of threadUuid.h into the checkout
    //was removed - the include-dir overlay below is the operative delivery and source
    //trees are never written.)

    const lib = b.addLibrary(.{
        .linkage = .dynamic,
        .name = "tcl9thread301",
        .root_module = b.createModule(.{
            .target = target,
            .optimize = optimize,
        }),
    });
    //lib.step.dependOn(&wf_uuidh.step);
    var flags = std.array_list.Managed([]const u8).init(b.allocator);
    defer flags.deinit();
    //try flags.appendSlice(&.{ "-Wall", "-O2", "-fomit-frame-pointer", "-DNDEBUG" });
    try flags.appendSlice(&.{ "-Wall", "-O3", "-fomit-frame-pointer" });
    try flags.appendSlice(&.{
        "-DPACKAGE_NAME=\"thread\"",
        "-DPACKAGE_TARNAME=\"thread\"",
        "-DPACKAGE_VERSION=\"3.0.1\"",
        "-DPACKAGE_STRING=\"thread 3.0.1\"",
        "-DPACKAGE_BUGREPORT=\"\"",
        "-DPACKAGE_URL=\"\"",
        "-DTCL_CFG_OPTIMIZED=1",
        "-DUSE_TCL_STUBS=1",
        "-DZIPFS_BUILD=1",
        "-DTCL_WIDE_INT_TYPE=long long",
        //"-DHAVE_STDIO_H=1",
        //"-DHAVE_STDLIB_H=1",
        //"-DHAVE_STRING_H=1",
        "-DHAVE_INTTYPES_H=1",
        //"-DHAVE_STDINT_H=1",
        //"-DHAVE_STRINGS_H=1",
        //"-DHAVE_SYS_STAT_H=1",
        //"-DHAVE_SYS_TYPES_H=1",
        //"-DHAVE_FILE_OFFSET_BITS=64",
        //"-DHAVE_STRUCT_STAT64=1",
        //"-DHAVE_LSEEK64=1",

        "-static-libgcc",
    });

    //BUILD_<somelibrary> needs to be defined for windows
    if (target.result.os.tag == .windows) {
        try flags.appendSlice(&.{
            "-DBUILD_thread=/**/",
        });
    }

    var tclthread_sources = std.array_list.Managed([]const u8).init(b.allocator);
    try tclthread_sources.append(subdir ++ "/generic/threadNs.c");
    try tclthread_sources.append(subdir ++ "/generic/threadCmd.c");
    try tclthread_sources.append(subdir ++ "/generic/threadSvCmd.c");
    try tclthread_sources.append(subdir ++ "/generic/threadSpCmd.c");
    try tclthread_sources.append(subdir ++ "/generic/threadPoolCmd.c");
    try tclthread_sources.append(subdir ++ "/generic/psGdbm.c");
    try tclthread_sources.append(subdir ++ "/generic/psLmdb.c");
    try tclthread_sources.append(subdir ++ "/generic/threadSvListCmd.c");
    try tclthread_sources.append(subdir ++ "/generic/threadSvKeyListCmd.c");
    try tclthread_sources.append(subdir ++ "/generic/tclXkeylist.c");

    //if (target.result.os.tag == .windows) {
    //    lib.root_module.linkSystemLibrary("advapi32", .{}); //crypt
    //}
    lib.root_module.addIncludePath(b.path(subdir));
    lib.root_module.addIncludePath(b.path(subdir ++ "/generic"));
    //generated threadUuid.h: current thread trunk #includes it (upstream makefiles
    //generate it into their build dir); using the generator's output dir as an include
    //path also gives the compile its dependency on the generation step.
    lib.root_module.addIncludePath(threaduuid_file.dirname());
    lib.root_module.addIncludePath(b.path(tcldir ++ "/generic")); //todo - fix
    lib.root_module.addCSourceFiles(.{
        .files = tclthread_sources.items,
        .flags = flags.items,
    });

    lib.root_module.linkLibrary(stublib);
    lib.root_module.link_libc = true;
    //thread.rc overlay (G-102): the version resource needs tcl.h; the recipe
    //historically carried that as an edit of the checkout's thread.rc - now the rc
    //is compiled from an overlay copy with the include inserted (and the historical
    //relative-path edit normalized if a previously-mutated tree is staged), with
    //tcl.h resolving via the include paths. Source trees are never written.
    var threadrc_content: []const u8 = common.readSourceFile(b, subdir ++ "/win/thread.rc");
    const legacy_edit = "#include \"../../tcl905/generic/tcl.h\"";
    if (std.mem.indexOf(u8, threadrc_content, legacy_edit) != null) {
        threadrc_content = common.replaceAll(b, threadrc_content, legacy_edit, "#include \"tcl.h\"");
    } else if (std.mem.indexOf(u8, threadrc_content, "#include \"tcl.h\"") == null) {
        threadrc_content = common.replaceAll(b, threadrc_content, "#include <winver.h>", "#include <winver.h>\n#include \"tcl.h\"");
    }
    const wf_threadrc = b.addWriteFiles();
    const threadrc_overlay = wf_threadrc.add("thread.rc", threadrc_content);
    lib.root_module.addWin32ResourceFile(.{
        .file = threadrc_overlay,
        .flags = &.{
            "-DPACKAGE_MAJOR=3",
            "-DPACKAGE_MINOR=0",
            "-DPACKAGE_VERSION=3.0b2",
        },
        .include_paths = &.{
            b.path(tcldir ++ "/generic"),
            b.path(subdir ++ "/win"),
        },
    }); //ignored for non-windows targets
    b.installArtifact(lib);

    //G-102: pkgIndex.tcl so 'package require Thread' resolves against the prefix
    //(punkshell runtests -jobs and codethread need it) - formerly a suite.tcl
    //post-build block.
    const wf_pkgidx = b.addWriteFiles();
    const pkgidx = wf_pkgidx.add("pkgIndex.tcl", "package ifneeded Thread " ++ mkvar_thread_version ++
        " [list load [file normalize [file join $dir .. .. bin " ++ mkvar_pkg_lib_file ++ "]] Thread]\n");
    const pkgidx_install = b.addInstallFileWithDir(pkgidx, .prefix, "lib/thread" ++ mkvar_thread_version ++ "/pkgIndex.tcl");
    b.getInstallStep().dependOn(&pkgidx_install.step);

    return lib;
}