#!/usr/bin/env bash
# Which packages of the workspace are tested where: see tools/README.md and docs/dev/build-and-test.md.
#
#   tools/test-partition check             fail when the classification and the workspace disagree
#   tools/test-partition packages <class>  print `-p a -p b` for cargo
#   tools/test-partition expr <class>      print a nextest filterset: `package(a) | package(b)`
#   tools/test-partition expr recorder-macos
#                                          the filterset of the recorder tests that run on macOS
#   tools/test-partition --self-test       run `check` against the tree and against deliberately broken copies
#
# The classification is tools/test-partition.json (class -> package names); it is the single source of truth
# for the CI jobs, the justfile and the Nix check sets (nix/windows). It needs only bash, cargo and jq.
#
# Environment (for the self-test): TEST_PARTITION_JSON overrides the classification file, and
# TEST_PARTITION_METADATA is a file with the output of `cargo metadata --format-version 1 --no-deps`.
set -euo pipefail

root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
json=${TEST_PARTITION_JSON:-$root/tools/test-partition.json}

classes="neutral os_sensitive windows linux macos mixed tool none"

# the crates a `neutral` package must not depend on, directly
platform_crates='["komorebi-windows","komorebi-macos","komorebi-linux"]'

# the tests of the recorder that run on macOS, by their module path: the macOS flavoured sources, which
# the recorder's other tests (the platform-neutral ones) share a binary with
recorder_macos_filter='package(komorebi-recorder) & test(/^(sources::oslog|av|capture::sck|platform|power|system_state)::/)'

die() {
    echo "test-partition: $*" >&2
    exit 1
}

metadata() {
    if [ -n "${TEST_PARTITION_METADATA:-}" ]; then
        cat "$TEST_PARTITION_METADATA"
    else
        (cd "$root" && cargo metadata --format-version 1 --no-deps)
    fi
}

valid_class() {
    case " $classes " in
        *" $1 "*) return 0 ;;
        *) return 1 ;;
    esac
}

check() {
    local meta problems
    meta=$(metadata)
    problems=$(
        jq -r --argjson platform "$platform_crates" --slurpfile part "$json" --arg classes "$classes" '
            ($part[0]) as $p
            | [ .packages[] ] as $pkgs
            | ($classes | split(" ")) as $known
            | (
                # classes the file has that are not part of the contract
                ($p | keys[] | select(. as $k | $known | index($k) | not)
                    | "unknown class \(.)"),
                # a member in no class, or in two
                ($pkgs[].name as $n
                    | [ $known[] as $c | select(($p[$c] // []) | index($n)) | $c ] as $in
                    | if ($in | length) == 0 then "\($n): in no class"
                      elif ($in | length) > 1 then "\($n): in two classes (\($in | join(", ")))"
                      else empty end),
                # a name that is no member (stale), or listed twice in one class
                ($known[] as $c | ($p[$c] // [])[] as $n
                    | select(($pkgs | map(.name) | index($n)) == null)
                    | "\($n) (\($c)): not a member of the workspace"),
                ($known[] as $c | ($p[$c] // []) | group_by(.)[] | select(length > 1)
                    | "\(.[0]): listed twice in \($c)"),
                # a neutral package that is not neutral
                ($pkgs[] | select(.name as $n | ($p.neutral // []) | index($n))
                    | .name as $n
                    | (.dependencies[]
                        | select(.target != null)
                        | "\($n): neutral, but depends on \(.name) only for \(.target)"),
                      (.dependencies[] | select(.name as $d | $platform | index($d))
                        | "\($n): neutral, but depends on the platform crate \(.name)")
                )
            )
        ' <<<"$meta"
    )
    if [ -n "$problems" ]; then
        echo "$problems" >&2
        echo "test-partition: tools/test-partition.json does not match the workspace" >&2
        return 1
    fi
}

members_of() {
    jq -r --arg c "$1" '.[$c] // [] | .[]' "$json"
}

cmd=${1:-}
case "$cmd" in
    check)
        check
        ;;
    packages)
        class=${2:-}
        valid_class "$class" || die "unknown class '$class' (one of: $classes)"
        members_of "$class" | sed 's/^/-p /' | paste -sd' ' -
        ;;
    expr)
        class=${2:-}
        if [ "$class" = recorder-macos ]; then
            echo "$recorder_macos_filter"
            exit 0
        fi
        valid_class "$class" || die "unknown class '$class' (one of: $classes)"
        members_of "$class" | sed 's/.*/package(&)/' | paste -sd'|' - | sed 's/|/ | /g'
        ;;
    --self-test)
        exec "$root/tools/test-partition.test" "$root/tools/test-partition"
        ;;
    *)
        sed -n '2,9p' "$0" | sed 's/^# \{0,1\}//' >&2
        exit 2
        ;;
esac