const std = @import("std");
const sokol = @import("sokol");

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

    const has_imgui = b.option(bool, "imgui", "ImGui integration") orelse (optimize == .Debug);
    const has_tracy = b.option(bool, "tracy", "Tracy integration") orelse (optimize == .Debug);

    const exe = b.addExecutable(.{
        .name = "game_2025_12_13",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),
            .target = target,
            .optimize = optimize,
            .link_libc = true
        }),
    });
    const exe_mod = exe.root_module;

    const tracy_dependency = b.dependency("tracy", .{
        .target = target,
        .optimize = optimize,
        .tracy_enable = has_tracy,
        .tracy_only_localhost = true
    });
    exe_mod.linkLibrary(tracy_dependency.artifact("tracy"));
    exe_mod.addImport("tracy", tracy_dependency.module("tracy"));

    const stb_dependency = b.dependency("stb", .{});
    exe_mod.addIncludePath(stb_dependency.path("."));

    const sokol_c_dependency = b.dependency("sokol_c", .{});
    exe_mod.addIncludePath(sokol_c_dependency.path("util"));

    const fontstash_dependency = b.dependency("fontstash", .{});
    exe_mod.addIncludePath(fontstash_dependency.path("src"));

    const tiled_dependency = b.dependency("tiled", .{});
    exe_mod.addImport("tiled", tiled_dependency.module("tiled"));

    const sokol_dependency = b.dependency("sokol", .{
        .target = target,
        .optimize = optimize,
        .with_sokol_imgui = has_imgui
    });

    exe_mod.addImport("sokol", sokol_dependency.module("sokol"));
    exe_mod.linkLibrary(sokol_dependency.artifact("sokol_clib"));

    var cflags_buffer: [64][]const u8 = undefined;
    var cflags = std.ArrayListUnmanaged([]const u8).initBuffer(&cflags_buffer);
    switch (sokol.resolveSokolBackend(.auto, target.result)) {
        .d3d11 => try cflags.appendBounded("-DSOKOL_D3D11"),
        .metal => try cflags.appendBounded("-DSOKOL_METAL"),
        .gl => try cflags.appendBounded("-DSOKOL_GLCORE"),
        .gles3 => try cflags.appendBounded("-DSOKOL_GLES3"),
        .wgpu => try cflags.appendBounded("-DSOKOL_WGPU"),
        else => @panic("unknown sokol backend"),
    }
    exe_mod.addIncludePath(b.path("src/libs"));
    exe_mod.addCSourceFile(.{
        .file = b.path("src/libs/sokol_fontstash_impl.c"),
        .flags = cflags.items
    });

    exe_mod.addCSourceFile(.{
        .file = b.path("src/libs/stb_image.c"),
        .flags = &.{}
    });

    if (has_imgui) {
        if (b.lazyDependency("cimgui", .{
            .target = target,
            .optimize = optimize,
        })) |cimgui_dependency| {
            sokol_dependency.artifact("sokol_clib").addIncludePath(cimgui_dependency.path("src"));
            exe_mod.addImport("cimgui", cimgui_dependency.module("cimgui"));
        }
    }

    var options = b.addOptions();
    options.addOption(bool, "has_imgui", has_imgui);
    options.addOption(bool, "has_tracy", has_tracy);
    exe_mod.addOptions("options", options);

    b.installArtifact(exe);

    {
        const run_step = b.step("run", "Run the app");

        const run_cmd = b.addRunArtifact(exe);
        run_step.dependOn(&run_cmd.step);

        run_cmd.step.dependOn(b.getInstallStep());

        if (b.args) |args| {
            run_cmd.addArgs(args);
        }
    }

    {
        const exe_tests = b.addTest(.{
            .root_module = exe.root_module,
        });

        const run_exe_tests = b.addRunArtifact(exe_tests);

        const test_step = b.step("test", "Run tests");
        test_step.dependOn(&run_exe_tests.step);
    }
}