# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

import hashlib
import json
import os

import mozpack.path as mozpath
from mozpack.files import FileFinder

GENERATED_SOURCE_EXTS = (".rs", ".c", ".h", ".cc", ".cpp")


def sha512_digest(data):
    """
    Generate the SHA-512 digest of `data` and return it as a hex string.
    """
    return hashlib.sha512(data).hexdigest()


def get_filename_with_digest(name, contents):
    """
    Return the filename that will be used to store the generated file
    in the S3 bucket, consisting of the SHA-512 digest of `contents`
    joined with the relative path `name`.
    """
    digest = sha512_digest(contents)
    return mozpath.join(digest, name)


def get_generated_sources():
    """
    Yield tuples of `(objdir-rel-path, file)` for generated source files
    in this objdir, where `file` is either an absolute path to the file or
    a `mozpack.File` instance.
    """
    import buildconfig

    # First, get the list of generated sources produced by the build backend.
    gen_sources = os.path.join(buildconfig.topobjdir, "generated-sources.json")
    with open(gen_sources, "r") as f:
        data = json.load(f)
    for f in data["sources"]:
        # Exclute symverscript
        if mozpath.basename(f) != "symverscript":
            yield f, mozpath.join(buildconfig.topobjdir, f)
    # Next, return all the files in $objdir/ipc/ipdl/_ipdlheaders.
    base = "ipc/ipdl/_ipdlheaders"
    finder = FileFinder(mozpath.join(buildconfig.topobjdir, base))
    for p, f in finder.find("**/*.h"):
        yield mozpath.join(base, p), f
    # Next, return any source files that were generated into the Rust
    # object directory.
    rust_build_kind = "debug" if buildconfig.substs.get("MOZ_DEBUG_RUST") else "release"
    base = mozpath.join(buildconfig.substs["RUST_TARGET"], rust_build_kind, "build")
    finder = FileFinder(mozpath.join(buildconfig.topobjdir, base))
    for p, f in finder:
        if p.endswith(GENERATED_SOURCE_EXTS):
            yield mozpath.join(base, p), f


def get_s3_region_and_bucket():
    """
    Return a tuple of (region, bucket) giving the AWS region and S3
    bucket to which generated sources should be uploaded.
    """
    region = "us-west-2"
    level = os.environ.get("MOZ_SCM_LEVEL", "1")
    bucket = {
        "1": "gecko-generated-sources-l1",
        "2": "gecko-generated-sources-l2",
        "3": "gecko-generated-sources",
    }[level]
    return (region, bucket)
