#!/usr/bin/env bash

home="${USERPROFILE}"
downloads="$home\\Downloads"
base="$home\\mamba"
channel=main
#channel=conda-forge

# micromamba stuff; doesn't affect python itself:
installer_version="0.23.3"
installer_sha256="d133dc61615b03fa953b6563c6d0f7362c5319c1ed164a4c1311b7f5e1868776"
installer_archive="micromamba-$installer_version-0.tar.bz2"
installer_remote="https://micromamba.snakepit.net/api/micromamba/win-64/$installer_version"
installer_path="Library/bin/micromamba.exe"

# remember not to use == when you mean = here:
python='python=3.10'

main_packages=(
    'pip>=21.2.4' # python package manager
)

# pip packages should be pinned with pure equality
# because they're not exported by mamba env export.
pypi_packages=(
    'hipsterplot==0.1' # terminal plotting
)

# end basic settings, begin functions:

check_installer() {
    [ -s "$1" ] || return
    printf '%s %s\n' "$installer_sha256" "$1" | sha256sum -c - || return
}

run_mamba() {
    # TODO: infer System32 path by envvars. (it's looking for chcp.exe)
    PATH="\
C:\\Windows\\System32:\
C:\\Windows\\" \
    "$fullbase\\Library\\bin\\micromamba.exe" --no-rc --no-env -r "$base" "$@"
}

run_python() {
    PATH="\
$fullbase\\envs\\$env:\
$fullbase\\envs\\$env\\Library\\mingw-w64\\bin:\
$fullbase\\envs\\$env\\Library\\bin" \
    "$fullbase\\envs\\$env\\python.exe" "$@"
}

find_msvc() {
    [ -n "$SYSTEMDRIVE" ] || { echo '$SYSTEMDRIVE must be set.' >&2; exit 1; }

    dirs= libs= lib= includes=
    local dir= temp=
    local profiles="Program Files (x86)"

    cd "$SYSTEMDRIVE" || return
    [ -d "$profiles" ] || return

    add_dir() {
        dir="$1"
        dir="${dir%/}"
        dir="$(readlink -f "$dir")" || { printf 'readlink failed: %s\n' "$1" >&2; return 1; }
        if [ ! -d "$dir" ] && [ -e "$dir" ]; then
            dir="${dir%/*}"
        fi
        [ -d "$dir" ] || { printf 'not a directory: %s\n' "$dir"; return 1; }
        dirs+=":$dir"
    }

    windir() {
        # TODO: don't use cygpath, somehow.
        temp="$(cygpath -w "$1")" || return
        [ -d "$temp" ] || return
    }

    dir="$profiles/Microsoft Visual Studio"
    [ -d "$dir" ] || return
    dir="$(find "$dir" -name cl.exe | grep -E '[\/]Hostx64[\/]x64[\/]cl.exe$' | LC_ALL=C sort | tail -n1)"
    add_dir "$dir" || return

    windir "${dir%/bin/*}/lib/x64" || return; libs+=";$temp"; lib="$temp"
    windir "${dir%/bin/*}/include" || return; includes+=";$temp"

    dir="$profiles/Windows Kits"
    [ -d "$dir" ] || return
    dir="$(find "$dir" -name rc.exe | grep -E '[\/]x64[\/]rc.exe' | LC_ALL=C sort | tail -n1)"
    add_dir "$dir" || return

    # NOTE: this next line relies on add_dir behavior a little.
    windir "$dir/ucrt" || return; includes+=";$temp"

    dir="${dir%/x64}"
    windir "${dir/bin/Lib}/um/x64" || return; libs+=";$temp"
    windir "${dir/bin/Lib}/ucrt/x64" || return; libs+=";$temp"
    windir "${dir/bin/Include}/ucrt" || return; includes+=";$temp"
    windir "${dir/bin/Include}/shared" || return; includes+=";$temp"

    dirs="${dirs#:}"
    libs="${libs#;}"
    includes="${includes#;}"
    #printf '%s\n' "DIRS: $dirs" >&2
    #printf '%s\n' "LIBS: $libs" >&2
    #printf '%s\n' "INCLUDES: $includes" >&2
    #exit 1
}

install_msvc() {
    [ -n "$SYSTEMDRIVE" ] || { echo '$SYSTEMDRIVE must be set.' >&2; exit 1; }
    [ -n "$COMSPEC" ] || { echo '$COMSPEC must be set.' >&2; exit 1; }

    # find the latest version: curl -I 'https://aka.ms/vs/17/release/vs_buildtools.exe'
    local uuid='05734053-383e-4b1a-9950-c7db8a55750d'
    local hash='fbfc005ace3e6b4990e9a4be0fa09e7face1af5ee1f61035c64dbc16c407aeda'
    local exe='vs_BuildTools.exe'
    local installer="$downloads\\$exe"
    local url="https://download.visualstudio.microsoft.com/download/pr/$uuid/$hash/$exe"
    local profiles="Program Files (x86)"

    [ -s "$installer" ] || curl -L "$url" -o "$installer" || return
    printf '%s %s\n' "$hash" "$installer" | sha256sum -c - || return

    cd "$SYSTEMDRIVE" || return
    [ -d "$profiles" ] || return

    local bt
    bt="$profiles\\Microsoft Visual Studio\\2022\\BuildTools"

    # TODO: use "update" instead of "install" when applicable.
    # despite the name, you can use the Windows 11 SDK (or at least this version of it)
    # to target as early as Windows 10 v1507.
    "$installer" --quiet --wait --norestart --nocache install \
        --add 'Microsoft.VisualStudio.Component.VC.Tools.x86.x64' \
        --add 'Microsoft.VisualStudio.Component.Windows11SDK.22000'
    local ret=$?

    # bash has run ERRORLEVEL through a modulus of 256, so some hacks are required.
    local code=0
    case $ret in
        (0)     code=0;; # success (probably)
        (58)    code=-1073741510;;
        (65)    code=8001;;
        (66)    code=1602;; # NOTE: this could also be 8002!
        (67)    code=8003;;
        (68)    code=8004;;
        (69)    code=8005;;
        (70)    code=8006;;
        (82)    code=1618;;
        (87)    code="INVALID ARGUMENTS ($ret)";;
        (105)   code=1641;;
        (139)   code=5003;;
        (140)   code=5004;;
        (141)   code=5005;;
        (143)   code=5007;;
        (145)   code=-1073720687;;
        (194)   code=3010;; # success; restart required (but not really)
        (228)   code=740;;
        (233)   code=1001;;
        (235)   code=1003;;
        (*)     code="UNKNOWN ($ret)";;
    esac

    printf '%s exited with %%ERRORLEVEL%% %s.\n' "$installer" "$code" >&2
    [ "$code" = 0 ] || [ "$code" = 3010 ] || return 1
}

run_with_compiler() {
    find_msvc || install_msvc \
     || { printf 'failed to install MSVC and a Windows SDK.\n' >&2; exit 1; }
    find_msvc \
     || { printf 'failed to find a valid installation of MSVC.\n' >&2; exit 1; }

    cd "$working_dir" || return
    PATH="\
$fullbase\\envs\\$env:\
$fullbase\\envs\\$env\\Library\\mingw-w64\\bin:\
$fullbase\\envs\\$env\\Library\\bin:\
$dirs" \
    LIB="$libs" \
    LIBPATH="$lib" \
    INCLUDE="$includes" \
    python.exe "$@"
}

run_pip() {
    run_with_compiler -m pip --disable-pip-version-check "$@"
}

find_last_env() {
    local arg="$1" e= oe=
    env="$(date -u '+%Y%m%d')" || exit
    n=1
    while [ -d "$fullbase\\envs\\$env-$n" ]; do
        let n++
    done
    new_env="$env-$n"
    let n--
    if [ $n = 0 ]; then
        env=_
        if [ -d "$fullbase\\envs" ]; then
            for e in "$fullbase\\envs/"*; do # must use a forward slash for some reason
                oe="${e##*/}"
                #printf 'considering %s... compared to %s\n' "$oe" "$env" >&2
                if [ -d "$e" ] && [ "${oe#20}" != "$oe" ] && [[ "$oe" > "$env" ]]; then
                    #printf '%s is more recent!\n' "$oe"
                    env="$oe"
                fi
            done
        fi
        if [ "$env" = _ ]; then
            env=ERROR
            if [ "$arg" != new ]; then
                echo 'failed to find most recent environment' >&2
                exit 1
            fi
        fi
    else
        env="$env-$n"
    fi
}

# end of functions, begin main:

working_dir="$PWD"

[ -n "$USERPROFILE" ] || { echo '$USERPROFILE must be set.' >&2; exit 1; }
[ -d "$working_dir" ] || { echo 'wat?' >&2; exit 1; }

[ -d "$base" ] || mkdir "$base" || exit
fullbase="$(cygpath -u "$base")" || exit
fullbase="$(readlink -f "$fullbase")" || exit
fullbase="$(cygpath -w "$fullbase")" || exit

version="unknown"
if [ -s "$fullbase\\$installer_path" ]; then
    # TODO: do something meaningful if the execution itself fails.
    version="$(run_mamba --version)"
fi

if [ "$version" != "$installer_version" ]; then
    archive="$downloads\\$installer_archive"
    if check_installer "$archive"; then
        :
    else
        # slightly less safe:
        # curl -LOJ "$installer_remote"
        curl -L "$installer_remote" -o "$archive" || exit
        check_installer "$archive" || exit
    fi
    archive="$(cygpath -u "$archive")" || exit
    cd "$fullbase" || exit
    tar jxf "$archive" "$installer_path" || exit
    cd "$working_dir" || exit
fi

[ "$1" = --create ] && creating=1 || creating=0
[ "$1" = --mamba ] && dancing=1 || dancing=0
[ "$1" = --pip ] && compiling=1 || compiling=0
[ "$1" = --wheel ] && wheeling=1 || wheeling=0

find_last_env new || exit

if [ $dancing = 1 ]; then
    [ $dancing = 0 ] || shift || exit

    no_default=0
    for arg in "$@"; do
        [ "$arg" != --name ] || no_default=1
        # TODO: is --name=stuff valid? detect that too.
        if [ "${arg#--}" = "$arg" ]; then # ignore other long arguments
            # detect -n, -asdfn shortargs. startswith -, endswith n.
            if [ "${arg#-}" != "$arg" ] && [ "${arg%n}" != "${arg}" ]; then
                no_default=1
            fi
        fi
    done
    if [ $no_default = 0 ]; then
        run_mamba -n "$env" "$@" || exit
    else
        run_mamba "$@" || exit
    fi

    [ $dancing = 0 ] || exit 0
fi

if [ $compiling = 1 ]; then
    [ $compiling = 0 ] || shift || exit

    [ "$env" != ERROR ] || { printf 'failed to find most recent environment\n' >&2; exit 1; }
    run_pip "$@" || exit

    [ $compiling = 0 ] || exit 0
fi

if [ $wheeling = 1 ]; then
    [ $wheeling = 0 ] || shift || exit

    [ "$env" != ERROR ] || { printf 'failed to find most recent environment\n' >&2; exit 1; }
    run_with_compiler -u setup.py bdist_wheel || exit

    [ $wheeling = 0 ] || exit 0
fi

if [ "$env" = ERROR ] || [ $creating != 0 ]; then
    [ $creating = 0 ] || shift || exit
    env="$new_env"

    if [ $creating = 0 ]; then
        printf 'WARNING: automatically creating a new environment: %s' "$env" >&2
    fi

    run_mamba -yqn "$env" create -c "$channel" \
    "$python" "${main_packages[@]}" 2>&1 \
      | tee "$fullbase\\create.log"
    res=${PIPESTATUS[0]}
    if [ $res != 0 ]; then
        grep -F 'Could not solve for environment specs' "$fullbase\\create.log" || exit $res
        # run it again but without quiet so it can actually be debugged.
        run_mamba -yn "$env" create -c "$channel" \
        "$python" "${main_packages[@]}" 2>&1 \
          | tee "$fullbase\\create.log"
        exit ${PIPESTATUS[0]}
    fi

    common=(--isolated --disable-pip-version-check)
    run_pip install "${common[@]}" --no-deps "${pypi_packages[@]}" 2>&1 \
      | tee -a "$fullbase\\create.log"
    [ ${PIPESTATUS[0]} = 0 ] || exit ${PIPESTATUS[0]}
    # using run_python is faster than run_pip since it won't check for compilers.
    run_python -m pip "${common[@]}" check \
      | tee -a "$fullbase\\create.log"
    #[ ${PIPESTATUS[0]} = 0 ] || exit ${PIPESTATUS[0]}

    pre="$fullbase\\$env"

    run_mamba -n "$env" env export > "$pre.yml" || exit

    run_mamba -n "$env" list --json | run_python -c \
    'for p in (m:=__import__)("json").load(m("sys").stdin):print(p["name"]+"=="+p["version"])' \
      > "$pre.conda.freeze.txt" || exit
    [ ${PIPESTATUS[0]} = 0 ] || exit ${PIPESTATUS[0]}

    run_python -m pip "${common[@]}" list --pre --format=freeze \
      > "$pre.pip.freeze.txt" || exit

    echo '- pip:' | cat "$pre.yml" - > "$pre.with-pip.yml" || exit
    run_python -c \
    '[print(*" -",b[k]) for a,b in [map(lambda f:{l.strip().lower().replace(*"-_"):l.strip() for l in open(f)},__import__("sys").argv[1:])] for k in b if k not in a]' \
    "$pre.conda.freeze.txt" "$pre.pip.freeze.txt" \
     >> "$pre.with-pip.yml" || exit

    rm "$pre.conda.freeze.txt" "$pre.pip.freeze.txt" || exit

    [ $creating = 0 ] || exit 0
fi

run_python "$@"