.hie-bios

#!/usr/bin/env bash

# hie-bios passes in HIE_BIOS_ARG, but this script accepts an argument for testing alternatively
arg="${HIE_BIOS_ARG-$1}"

ws=$(bazel info workspace)
execroot=$(bazel info execution_root)

# make arg relative to workspace
source="${arg#"$ws"/}"

# determine the haskell_binary or haskell_library target of the source file
declare -a target
mapfile -t target < <(
    bazel query "let uses = rdeps(//..., $source, 2) in kind(_haskell_library, \$uses) union kind(_haskell_binary, \$uses)"
)

function die() {
    echo "$@" >&2
    exit 1
}

case "${#target[@]}" in
    1) ;;
    0)
        die "could not determine haskell target for $arg"
        ;;
    *)
        die "matched multiple targets for $arg"
        ;;
esac

# build all dependent targets
declare -a dep_targets
mapfile -t dep_targets < <(bazel query "kind(rule, deps(${target[0]}, 1))")

if [[ "${#dep_targets[@]}" -ge 1 ]]; then
    bazel build "${dep_targets[@]}"
fi

hie_bios_flags() {
    echo -i
    bazel run "${target[0]}@repl@bios" | while read -r line; do
        # The bios script references files in the execroot bazel folder.
        #
        # We need to re-map the files back to to the workspace directory since
        # the IDE should not try to open files inside of the execroot (and the
        # hls would not work there).
        #
        # Also, hie-bios / ghcide needs to be able to locate files in the search
        # path (given with -i flags). This is how it learns about the source files
        # it should track, otherwise it will not be able to load modules from the
        # same component. So we also have to map the search paths referencing
        # the execroot back to the workspace too.
        if [[ "$line" = "$execroot/"* ]]; then
            relpath="${line#"$execroot/"}"
            if [[ -f "$relpath" ]]; then
                echo "$relpath"
                continue
            fi
        elif [[ "$line" = "-i$execroot/"* ]]; then
            relpath="${line#-i"$execroot"/}"
            if [[ -d "$relpath" ]]; then
                echo "-i$relpath"
                continue
            fi
        fi
        echo "$line"
    done
    # Make warnings non-fatal
    echo -Wwarn
}

hie_bios_deps() {
    bazel query "filter(\"^//\", buildfiles(deps(${target[0]})))" | while read -r label; do
        package="${label#//}"
        package="${package%:*}"
        file="${label#*:}"

        echo "$package/$file"
    done
}

if [[ -z "${HIE_BIOS_DEPS-}" ]]; then
    hie_bios_deps >&2
else
    hie_bios_deps >"$HIE_BIOS_DEPS"
fi

if [[ -z "${HIE_BIOS_OUTPUT-}" ]]; then
    hie_bios_flags
else
    hie_bios_flags >"$HIE_BIOS_OUTPUT"
fi