const std = @import("std");

pub fn build(b: *std.Build) void {

    //// Compilation options

    // Static/Dynamic linkage
    const opt_shared = b.option(
        bool,
        "shared",
        "Build as a dynamic (shared) library",
    ) orelse false;

    // `zig build test`
    const opt_test = b.step(
        "test",
        "Run library tests",
    );

    //// Build Context
    var ctx = BuilderContext{
        .b = b,
        // Configuration
        .target = b.standardTargetOptions(.{}),
        .optimize = b.standardOptimizeOption(.{}),
        .linkage = if (opt_shared) .static else .dynamic,
        .test_step = opt_test
    };


    //// Library
    
    // Create root module
    const root_module = ctx.createModule("src/root.zig");

    // Create library
    const lib_obj = b.addLibrary(.{
        .name = "reticulum-zero",
        .linkage = ctx.linkage,
        .root_module = root_module,
    });

    // Output library object
    b.installArtifact(lib_obj);


    ////////// Testing
    //
    
    ctx.addTestModule(root_module);
    ctx.addTestFile("src/packet.zig");
}


////////////// BuildContext
//

// Holds all the context values during build and provides related functions
const BuilderContext = struct {
 
    ////////// Properties
    //

    b: *std.Build,
    target: std.Build.ResolvedTarget,
    optimize: std.builtin.OptimizeMode,
    linkage: std.builtin.LinkMode,
    test_step: *std.Build.Step,

    ////////// Functions
    //

    // Creates a zig build module
    fn createModule(self: *BuilderContext, file: []const u8) *std.Build.Module {

        return self.b.createModule(.{
            .root_source_file = self.b.path(file),
            .target = self.target,
            .optimize = self.optimize,
        });
    }
    
    // Adds a source file's own tests to the tests list
    fn addTestFile(self: *BuilderContext, file: []const u8) void {

        const module = self.createModule(file);
        self.addTestModule(module);
    }

    // Adds a module's own tests to the tests list
    fn addTestModule(self: *BuilderContext, module: *std.Build.Module) void {

        const unit_tests = self.b.addTest(.{
            .root_module = module,
        });
        const run_tests = self.b.addRunArtifact(unit_tests);
        self.test_step.dependOn(&run_tests.step);
    }
};