"""
Helper library to create Prototype JS library.
"""

load("@aspect_rules_js//js:defs.bzl", "js_library")
load("@npm//:protobufjs/package_json.bzl", "bin")
load("@rules_proto//proto:defs.bzl", "ProtoInfo")

def _proto_sources_impl(ctx):
    return DefaultInfo(files = ctx.attr.proto[ProtoInfo].transitive_sources)

_proto_sources = rule(
    doc = """Provider Adapter from ProtoInfo to DefaultInfo.
        Extracts the transitive_sources from the ProtoInfo provided by the proto attr.
        This allows a macro to access the complete set of .proto files needed during compilation.
        """,
    implementation = _proto_sources_impl,
    attrs = {"proto": attr.label(providers = [ProtoInfo])},
)

def ts_proto_library(name, proto, deps = [], srcs = [], out_dir = "dist", **kwargs):
    """Minimal wrapper macro around pbjs/pbts tooling

    Args:
        name: name of generated js_library target, also used to name the .js/.d.ts outputs
        proto: label of a single proto_library target to generate for
        srcs: sources used by the librar
        out_dir: the target directory for created library
        deps: list of dependencies
        **kwargs: passed through to the js_library
    """
    js_out = ""
    if out_dir:
        js_out = out_dir + "/"

    js_out = js_out + "index.js"
    ts_out = js_out.replace(".js", ".d.ts")

    # Generate some target names, based on the provided name
    # (so that they are unique if the macro is called several times in one package)
    proto_target = "_%s_protos" % name
    js_target = "_%s_pbjs" % name
    ts_target = "_%s_pbts" % name

    # grab the transitive .proto files needed to compile the given one
    _proto_sources(
        name = proto_target,
        proto = proto,
    )

    # Transform .proto files to a single _pb.js file named after the macro
    bin.pbjs(
        name = js_target,
        srcs = [":" + proto_target],
        copy_srcs_to_bin = False,
        chdir = "../../../",
        # Arguments documented at
        # https://github.com/protobufjs/protobuf.js/tree/6.8.8#pbjs-for-javascript
        args = [
            "--target=static-module",
            "--wrap=default",
            "--strict-long",  # Force usage of Long type with int64 fields
            "--out=$@",
            "$(execpaths %s)" % proto_target,
        ],
        outs = [js_out],
    )

    # Transform the _pb.js file to a .d.ts file with TypeScript types
    bin.pbts(
        name = ts_target,
        srcs = [js_target],
        copy_srcs_to_bin = False,
        chdir = "../../../",
        # Arguments documented at
        # https://github.com/protobufjs/protobuf.js/tree/6.8.8#pbts-for-typescript
        args = [
            "--out=$@",
            "$(execpath %s)" % js_target,
        ],
        outs = [ts_out],
    )

    # Expose the results as js_library which provides DeclarationInfo for interop with other rules

    js_library(
        name = name,
        srcs = srcs + [
            js_target,
            ts_target,
            js_out,
            ts_out,
        ],
        deps = deps + [
            "//:node_modules/long",
            "//:node_modules/@types/long",
            "//:node_modules/protobufjs",
            "//:node_modules/@types/protobufjs",
        ],
        data = [
            "//:node_modules/long",
            "//:node_modules/@types/long",
            "//:node_modules/protobufjs",
            "//:node_modules/@types/protobufjs",
        ],
        **kwargs
    )