load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

def _jsonnet_deps_impl(ctx):
    # 1. Read the lockfile
    # We assume the lockfile is at //third_party/jsonnet/jsonnetfile.lock.json
    # relative to the module root.
    lockfile_content = ctx.read(ctx.path(Label("//third_party/jsonnet:jsonnetfile.lock.json")))
    lockfile = json.decode(lockfile_content)

    # 2. Iterate over dependencies
    for dep in lockfile.get("dependencies", []):
        source = dep.get("source", {})
        git_source = source.get("git", {})
        
        remote = git_source.get("remote")
        commit = dep.get("version")
        subdir = git_source.get("subdir", "")
        
        # Construct a unique name for the repository
        # e.g., https://github.com/grafana/jsonnet-libs.git (subdir: tanka-util) -> github_com_grafana_jsonnet_libs_tanka_util
        name_part = remote.removeprefix("https://").removeprefix("http://").removesuffix(".git")
        repo_name = name_part.replace("/", "_").replace("-", "_").replace(".", "_")
        if subdir:
            repo_name += "_" + subdir.replace("/", "_").replace("-", "_").replace(".", "_")
            subdir += "/"
        
        # Optional: Use http_archive for GitHub to avoid git overhead
        if "github.com" in remote:
            # https://github.com/user/repo.git -> https://github.com/user/repo/archive/<commit>.zip
            url = remote.removesuffix(".git") + "/archive/" + commit + ".zip"
            http_archive(
                name = repo_name,
                url = url,
                # We interpret "subdir" by generating a BUILD file that exposes files in that subdir.
                # Because the archive unzips to "repo-commit", we usually strip_prefix.
                # However, predicting strip_prefix is hard without knowing the repo name in the zip.
                # GitHub usually uses "repo-name-commit" or "repo-name-tag".
                # For safety in this prototype, we'll strip the first component.
                strip_prefix = remote.split("/")[-1].removesuffix(".git") + "-" + commit,
                build_file_content = """
load("@rules_jsonnet//jsonnet:jsonnet.bzl", "jsonnet_library")

jsonnet_library(
    name = "lib",
    srcs = glob(["{subdir}**/*.libsonnet", "{subdir}**/*.jsonnet", "{subdir}**/*.json"], allow_empty = True),
    visibility = ["//visibility:public"],
)
""".format(subdir = subdir)
            )
        else:
            # Fallback to git_repository for non-GitHub
            git_repository(
                name = repo_name,
                remote = remote,
                commit = commit,
                build_file_content = """
load("@rules_jsonnet//jsonnet:jsonnet.bzl", "jsonnet_library")

jsonnet_library(
    name = "lib",
    srcs = glob(["{subdir}**/*.libsonnet", "{subdir}**/*.jsonnet", "{subdir}**/*.json"], allow_empty = True),
    visibility = ["//visibility:public"],
)
""".format(subdir = subdir)
            )

jsonnet_deps = module_extension(
    implementation = _jsonnet_deps_impl,
)