#!/usr/bin/python3
"""
To run it needs the following:
cargo install rustfilt
rustup component add --toolchain nightly llvm-tools-preview
"""
import os
import re
import sys
import subprocess
from glob import glob

# Compute the coverage for all fuzzing targets, or not
FUZZING = True

ROOT = os.path.dirname(os.path.abspath(__file__))
target_folder = os.path.join(ROOT, "target")
# Get info about the rust installation
rustup_info = subprocess.check_output("rustup show", shell=True).decode()
arch = re.findall(r"Default host: (.+)", rustup_info)[0]

# Get where LLVM is installed
sysroot = subprocess.check_output("rustc --print sysroot", shell=True).decode().strip()
llvm_path = os.path.join(sysroot, "lib", "rustlib", arch, "bin")

# Check that people can read the doc
if not os.path.exists(os.path.join(llvm_path, "llvm-profdata")):
    print("PLEASE run:")
    print("rustup component add --toolchain nightly llvm-tools-preview")
    print("cargo install rustfilt")
    sys.exit(1)

# Settings
test_cov_path = os.path.join(target_folder, "cargo-test-cov-%p-%m.profraw")
final_cov_path = os.path.join(target_folder, "total_coverage.profdata")
doc_tests_bin = os.path.join(target_folder, "doctestbins")

cov_files = []
exec_files = []

# Clean up the targets folder
subprocess.check_call(
    "cargo clean",
    shell=True,
    cwd=ROOT,
)
# Create a folder for the test coverage
os.makedirs(target_folder, exist_ok=True)

out = subprocess.check_output(
    "cargo test",
    shell=True,
    cwd=ROOT,
    stderr=subprocess.STDOUT,
    universal_newlines=True,
    env={
        **os.environ,
        "CARGO_INCREMENTAL":"0",
        "RUSTFLAGS": "-C instrument-coverage",
        "RUSTDOCFLAGS":"-Cinstrument-coverage -Z unstable-options --persist-doctests {}".format(doc_tests_bin),
        "LLVM_PROFILE_FILE": test_cov_path,
    },
)

# For the doctests see:
# https://github.com/rust-lang/rust/issues/79417

# add the test binaries
exec_files.extend(
    os.path.join(ROOT, file)
    for file in re.findall(r"Running \S+ \((target/.+?)\)", out)
)
# add all the doc tests binaries
exec_files.extend(
    file
    for file in glob(os.path.join(doc_tests_bin, "**", "*"))
)
cov_files.extend(
    os.path.join(os.path.dirname(test_cov_path), file)
    for file in os.listdir(os.path.dirname(test_cov_path))
    if file.endswith(".profraw")
)

if FUZZING:
    # Get the list of fuzzing targets
    fuzz_targets = (
        subprocess.check_output(
            "cargo fuzz list",
            shell=True,
            cwd=ROOT,
        )
        .decode()
        .split("\n")[:-1]
        )[:1]
    # Generate coverage for all the targets
    for fuzz_target in fuzz_targets:
        subprocess.check_call(
            "cargo fuzz coverage {}".format(fuzz_target),
            shell=True,
            cwd=ROOT,
        )

    cov_files.extend(
        os.path.join(ROOT, "fuzz", "coverage", fuzz_target, "coverage.profdata")
        for fuzz_target in fuzz_targets
    )
    exec_files.extend(
        os.path.join(
            ROOT, "target", arch, "coverage", arch, "release", fuzz_target
        )
        for fuzz_target in fuzz_targets
    )

# Merge the coverages into an unique file
subprocess.check_call(
    "{}/llvm-profdata merge -sparse {} -o {}".format(
        llvm_path,
        " ".join(cov_files),
        final_cov_path,
    ),
    shell=True,
    cwd=ROOT,
)

# Create the report!
subprocess.check_call(
    (
        "{}/llvm-cov report --Xdemangler=rustfilt --instr-profile={} "
        "-ignore-filename-regex='.cargo' -object {}"
    ).format(
        llvm_path,
        final_cov_path,
        " -object ".join(exec_files),
    ),
    shell=True,
    cwd=ROOT,
)