#!/usr/bin/env bash

# The optional application categories: what the interview offers, and what
# choosing one actually installs.
#
# The rules:
#
#   1. Every category the interview offers installs something. The menu is read
#      from the directory rather than written down, so an empty or missing file
#      is a checkbox that does nothing -- the same defect this repository has
#      refused to ship twice now.
#   2. A `flatpak:` line reaches flatpak with the prefix removed, and never
#      reaches dnf. Getting this backwards installs nothing and says it did.
#   3. Nothing is installed without being asked for. An extras loop that ran on
#      its own defaults would put Steam on a work laptop.
#   4. Every name is a real package. The whole point of admitting applications
#      one at a time from dnf or Flathub is that they stay installable; a typo
#      here is a category that fails on somebody else's machine, not this one.
#      Checked against the actual repositories, and skipped when offline.

set -uo pipefail

repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
installer="$repo_dir/setup/scripts/install-packages"
interview="$repo_dir/setup/scripts/interview"
extras_dir="$repo_dir/setup/packages/extras"

findings=()
note() { findings+=("$1"); }

[[ -d "$extras_dir" ]] || { printf 'extras contract: no %s\n' "$extras_dir" >&2; exit 1; }

# ── 1. Every category is a real offer ────────────────────────────────────────

shopt -s nullglob
categories=("$extras_dir"/*)
(( ${#categories[@]} > 0 )) || note 'the extras directory is empty, so the checklist offers nothing'

for category in "${categories[@]}"; do
    name="$(basename "$category")"
    [[ -f "$category" ]] || { note "$name is not a file"; continue; }
    entries="$(sed 's/#.*//' "$category" | tr -d ' \t' | grep -cv '^$')"
    (( entries > 0 )) || note "the $name category installs nothing, so choosing it does nothing"
done

# The menu has to come from the directory. A hardcoded list is one that goes
# stale the first time a category is added.
grep -q 'extras_dir' "$interview" \
    || note 'the interview does not read the categories from the extras directory'
grep -q 'gum choose --no-limit' "$interview" \
    || note 'the interview does not offer the categories as a multiple-choice checklist'

# ── 2 & 3. What a chosen category actually installs ──────────────────────────

work="$(mktemp -d)"
trap 'rm -rf "$work"' EXIT

filter="$(sed -n '/^packages_in()/,/^}/p' "$installer")"
loop="$(sed -n '/^install_extra_category()/,/^}/p' "$installer")"
[[ -n "$filter" && -n "$loop" ]] || {
    printf 'extras contract: install-packages no longer defines packages_in and install_extra_category\n' >&2
    exit 1
}

stub_dir="$work/bin"
mkdir -p "$stub_dir"
calls="$work/calls"
for command in dnf flatpak; do
    cat >"$stub_dir/$command" <<STUB
#!/usr/bin/env bash
printf '%s %s\n' "$command" "\$*" >>"$calls"
STUB
    chmod +x "$stub_dir/$command"
done
cat >"$stub_dir/sudo" <<'STUB'
#!/usr/bin/env bash
exec "$@"
STUB
chmod +x "$stub_dir/sudo"

fixture="$work/mixed"
cat >"$fixture" <<'LIST'
# Both managers in one category, which is the case this format exists for.
from-dnf
flatpak:org.example.FromFlathub
LIST

(
    PATH="$stub_dir:$PATH"
    log() { :; }
    eval "$filter"
    eval "$loop"
    install_extra_category "$fixture"
)

recorded="$(cat "$calls" 2>/dev/null)"

grep -q 'dnf install -y from-dnf' <<<"$recorded" \
    || note 'a bare line in a category is not installed with dnf'
grep -q 'flatpak install -y flathub org.example.FromFlathub' <<<"$recorded" \
    || note 'a flatpak: line does not reach flatpak with the prefix removed'
if grep 'dnf install' <<<"$recorded" | grep -q 'flatpak:'; then
    note 'a flatpak: line is passed to dnf, which cannot install it'
fi
if grep 'flatpak install' <<<"$recorded" | grep -q 'from-dnf'; then
    note 'a dnf package is passed to flatpak'
fi

# Choosing nothing installs nothing.
: >"$calls"
(
    PATH="$stub_dir:$PATH"
    PANAMA_PATH="$repo_dir"
    log() { :; }
    eval "$filter"
    eval "$loop"
    EXTRAS_DIR="$extras_dir"
    for extra in ${PANAMA_EXTRAS:-}; do
        [[ -f "$EXTRAS_DIR/$extra" ]] && install_extra_category "$EXTRAS_DIR/$extra"
    done
)
[[ -s "$calls" ]] && note 'with no categories chosen the installer still installed something'

# ── 4. Every name resolves ───────────────────────────────────────────────────
#
# Skipped rather than failed when the repositories cannot be reached, so this
# contract stays runnable on a train.

if timeout 60 dnf list --available --quiet bash >/dev/null 2>&1; then
    for category in "${categories[@]}"; do
        [[ -f "$category" ]] || continue
        while read -r package; do
            [[ -n "$package" ]] || continue
            [[ "$package" == flatpak:* ]] && continue
            timeout 90 dnf list --quiet "$package" >/dev/null 2>&1 \
                || note "$(basename "$category") names $package, which dnf cannot resolve"
        done < <(sed 's/#.*//' "$category" | tr -d ' \t' | grep -v '^$')
    done
else
    printf 'extras contract: dnf is unreachable, so package names were not resolved\n' >&2
fi

if timeout 60 flatpak remote-info flathub org.mozilla.firefox >/dev/null 2>&1; then
    for category in "${categories[@]}"; do
        [[ -f "$category" ]] || continue
        while read -r id; do
            [[ -n "$id" ]] || continue
            timeout 90 flatpak remote-info flathub "$id" >/dev/null 2>&1 \
                || note "$(basename "$category") names $id, which is not on Flathub"
        done < <(sed 's/#.*//' "$category" | tr -d ' \t' | sed -n 's/^flatpak://p')
    done
else
    printf 'extras contract: Flathub is unreachable, so flatpak IDs were not resolved\n' >&2
fi

# ── Report ───────────────────────────────────────────────────────────────────

if (( ${#findings[@]} > 0 )); then
    mapfile -t findings < <(printf '%s\n' "${findings[@]}" | sort -u)
    printf 'extras contract: %d finding(s)\n' "${#findings[@]}" >&2
    printf '  - %s\n' "${findings[@]}" >&2
    exit 1
fi

printf 'extras contract: PASS (%d categories)\n' "${#categories[@]}"