# This file is a part of Julia. License is MIT: https://julialang.org/license

using Random, Sockets

const STDLIB_DIR = Sys.STDLIB
const STDLIBS = filter!(x -> isfile(joinpath(STDLIB_DIR, x, "src", "$(x).jl")), readdir(STDLIB_DIR))

const TESTNAMES = [
        "tapir",  # TODO: move to the last
        "subarray", "core", "compiler", "worlds", "atomics",
        "keywordargs", "numbers", "subtype",
        "char", "strings", "triplequote", "unicode", "intrinsics",
        "dict", "hashing", "iobuffer", "staged", "offsetarray",
        "arrayops", "tuple", "reduce", "reducedim", "abstractarray",
        "intfuncs", "simdloop", "vecelement", "rational",
        "bitarray", "copy", "math", "fastmath", "functional", "iterators",
        "operators", "ordering", "path", "ccall", "parse", "loading", "gmp",
        "sorting", "spawn", "backtrace", "exceptions",
        "file", "read", "version", "namedtuple",
        "mpfr", "broadcast", "complex",
        "floatapprox", "stdlib", "reflection", "regex", "float16",
        "combinatorics", "sysinfo", "env", "rounding", "ranges", "mod2pi",
        "euler", "show", "client",
        "errorshow", "sets", "goto", "llvmcall", "llvmcall2", "ryu",
        "some", "meta", "stacktraces", "docs",
        "misc", "threads", "stress", "binaryplatforms", "atexit",
        "enums", "cmdlineargs", "int", "interpreter",
        "checked", "bitset", "floatfuncs", "precompile",
        "boundscheck", "error", "ambiguous", "cartesian", "osutils",
        "channels", "iostream", "secretbuffer", "specificity",
        "reinterpretarray", "syntax", "corelogging", "missing", "asyncmap",
        "smallarrayshrink", "opaque_closure", "filesystem", "download",
]

"""
`(; tests, net_on, exit_on_error, seed) = choosetests(choices)` selects a set of tests to be
run. `choices` should be a vector of test names; if empty or set to
`["all"]`, all tests are selected.

This function also supports "test collections": specifically, "linalg"
 refers to collections of tests in the correspondingly-named
directories.

The function returns a named tuple with the following elements:
  - `tests` is a vector of fully-expanded test names,
  - `net_on` is true if networking is available (required for some tests),
  - `exit_on_error` is true if an error in one test should cancel
    remaining tests to be run (otherwise, all tests are run unconditionally),
  - `seed` is a seed which will be used to initialize the global RNG for each
    test to be run.

Several options can be passed to `choosetests` by including a special token
in the `choices` argument:
   - "--skip", which makes all tests coming after be skipped,
   - "--exit-on-error" which sets the value of `exit_on_error`,
   - "--seed=SEED", which sets the value of `seed` to `SEED`
     (parsed as an `UInt128`); `seed` is otherwise initialized randomly.
     This option can be used to reproduce failed tests.
   - "--help", which prints a help message and then skips all tests.
   - "--help-list", which prints the options computed without running them.
"""
function choosetests(choices = [])
    tests = []
    skip_tests = Set()
    exit_on_error = false
    use_revise = false
    seed = rand(RandomDevice(), UInt128)
    ci_option_passed = false
    dryrun = false

    for (i, t) in enumerate(choices)
        if t == "--skip"
            union!(skip_tests, choices[i + 1:end])
            break
        elseif t == "--exit-on-error"
            exit_on_error = true
        elseif t == "--revise"
            use_revise = true
        elseif startswith(t, "--seed=")
            seed = parse(UInt128, t[(length("--seed=") + 1):end])
        elseif t == "--ci"
            ci_option_passed = true
        elseif t == "--help-list"
            dryrun = true
        elseif t == "--help"
            println("""
                USAGE: ./julia runtests.jl [options] [tests]
                OPTIONS:
                  --exit-on-error      : stop tests immediately when a test group fails
                  --help               : prints this help message
                  --help-list          : prints the options computed without running them
                  --revise             : load Revise
                  --seed=<SEED>        : set the initial seed for all testgroups (parsed as a UInt128)
                  --skip <NAMES>...    : skip test or collection tagged with <NAMES>
                TESTS:
                  Can be special tokens, such as "all", "unicode", "stdlib", the names of stdlib \
                  modules, or the names of any file in the TESTNAMES array (defaults to "all").

                  Or prefix a name with `-` (such as `-core`) to skip a particular test.
                """)
            return (; tests = [],
                      net_on = false,
                      exit_on_error = false,
                      use_revise = false,
                      seed = UInt128(0))
        elseif startswith(t, "--")
            error("unknown option: $t")
        elseif startswith(t, "-")
            push!(skip_tests, t[2:end])
        else
            push!(tests, t)
        end
    end

    unhandled = copy(skip_tests)

    requested_all     = "all"     in tests
    requested_default = "default" in tests
    if isempty(tests) || requested_all || requested_default
        append!(tests, TESTNAMES)
    end
    filter!(x -> x != "all",     tests)
    filter!(x -> x != "default", tests)

    function filtertests!(tests, name, files=[name])
       flt = x -> (x != name && !(x in files))
       if name in skip_tests
           filter!(flt, tests)
           pop!(unhandled, name)
       elseif name in tests
           filter!(flt, tests)
           prepend!(tests, files)
       end
    end

    explicit_pkg            = "Pkg"            in tests
    explicit_libgit2_online = "LibGit2/online" in tests

    filtertests!(tests, "unicode", ["unicode/utf8"])
    filtertests!(tests, "strings", ["strings/basic", "strings/search", "strings/util",
                   "strings/io", "strings/types"])
    # do subarray before sparse but after linalg
    filtertests!(tests, "subarray")
    filtertests!(tests, "compiler", ["compiler/inference", "compiler/validation",
        "compiler/ssair", "compiler/irpasses", "compiler/codegen",
        "compiler/inline", "compiler/contextual"])
    filtertests!(tests, "stdlib", STDLIBS)
    # do ambiguous first to avoid failing if ambiguities are introduced by other tests
    filtertests!(tests, "ambiguous")

    if startswith(string(Sys.ARCH), "arm")
        # Remove profile from default tests on ARM since it currently segfaults
        # Allow explicitly adding it for testing
        @warn "Skipping Profile tests because the architecture is ARM"
        filter!(x -> (x != "Profile"), tests)
    end

    net_required_for = [
        "Artifacts",
        "Downloads",
        "LazyArtifacts",
        "LibCURL",
        "LibGit2",
        "Sockets",
        "download",
    ]
    net_on = true
    JULIA_TEST_NETWORKING_AVAILABLE = get(ENV, "JULIA_TEST_NETWORKING_AVAILABLE", "") |>
                                      strip |>
                                      lowercase |>
                                      s -> tryparse(Bool, s) |>
                                      x -> x === true
    # If the `JULIA_TEST_NETWORKING_AVAILABLE` environment variable is set to `true`, we
    # always set `net_on` to `true`.
    # Otherwise, we set `net_on` to true if and only if networking is actually available.
    if !JULIA_TEST_NETWORKING_AVAILABLE
        try
            ipa = getipaddr()
        catch
            if ci_option_passed
                @error("Networking unavailable, but `--ci` was passed")
                rethrow()
            end
            net_on = false
            @warn "Networking unavailable: Skipping tests [" * join(net_required_for, ", ") * "]"
            filter!(!in(net_required_for), tests)
        end
    end

    if ccall(:jl_running_on_valgrind,Cint,()) != 0 && "rounding" in tests
        @warn "Running under valgrind: Skipping rounding tests"
        filter!(x -> x != "rounding", tests)
    end

    filter!(!in(tests), unhandled)
    filter!(!in(skip_tests), tests)

    new_tests = String[]
    for test in tests
        if test in STDLIBS
            testfile = joinpath(STDLIB_DIR, test, "test", "testgroups")
            if isfile(testfile)
                testgroups = readlines(testfile)
                length(testgroups) == 0 && error("no testgroups defined for $test")
                prepend!(new_tests, (test * "/") .* testgroups)
            else
                push!(new_tests, test)
            end
        end
    end
    filter!(x -> (x != "stdlib" && !(x in STDLIBS)) , tests)
    append!(tests, new_tests)

    requested_all || explicit_pkg            || filter!(x -> x != "Pkg",            tests)
    requested_all || explicit_libgit2_online || filter!(x -> x != "LibGit2/online", tests)

    # Filter out tests from the test groups in the stdlibs
    filter!(!in(tests), unhandled)
    filter!(!in(skip_tests), tests)

    if !isempty(unhandled)
        @warn "Not skipping tests: $(join(unhandled, ", "))"
    end

    if dryrun
        print("Tests enabled to run:")
        foreach(t -> print("\n  ", t), tests)
        if !isempty(skip_tests)
            print("\n\nTests skipped:")
            foreach(t -> print("\n  ", t), skip_tests)
        end
        print("\n")
        exit_on_error && (print("\nwith option "); printstyled("exit_on_error", bold=true))
        use_revise && (print("\nwith option "); printstyled("use_revise", bold=true); print(" (Revise.jl)"))
        print("\n\n")
        empty!(tests)
    end

    return (; tests, net_on, exit_on_error, use_revise, seed)
end