#!/usr/bin/env bash

# The battery, and the machines that do not have one.
#
# This is the first thing Panama has shipped that only exists on some hardware,
# and the failure that matters is not a wrong percentage -- it is a desktop
# growing battery chrome, or a laptop showing a confident 0% because a file
# could not be read. So the properties pinned here are mostly about absence:
#
#   1. No battery means `available` is false and every surface hides. Not 0%,
#      not "Unknown" in the bar, not an empty card on the Power page.
#   2. A machine with no mains supply at all is on wall power. A desktop must
#      never be treated as running on battery, or every battery-specific idle
#      timing would apply to it.
#   3. The charge-limit control appears only where the firmware has one.
#   4. The threshold write goes through panama-sudo with a reason, never bare
#      sudo, and is read back rather than assumed.
#   5. Health -- design-capacity percentage and charge cycles -- is reported
#      where sysfs reports it and is SILENT where it does not. Most of these
#      files are optional and plenty of firmware omits them, so the tempting
#      failure is a tile reading "100% of design capacity, 0 cycles" on a
#      three-year-old battery that simply never said. That is worse than no
#      tile: it is a confident wrong answer about whether hardware is dying.
#
# The helper is driven against fixture sysfs trees; the QML side is pinned
# statically, since a battery cannot be simulated into the running shell.

set -uo pipefail

repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
helper="$repo_dir/config/dot/quickshell/scripts/panama-battery"
service="$repo_dir/config/dot/quickshell/services/Battery.qml"
cluster="$repo_dir/config/dot/quickshell/modules/bar/StatusCluster.qml"
page="$repo_dir/config/dot/quickshell/modules/settings/PowerPage.qml"
schema="$repo_dir/config/dot/quickshell/config/PreferenceSchema.qml"
aliases="$repo_dir/config/dot/quickshell/config/Settings.qml"

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

[[ -x "$helper" ]] || { printf 'battery contract: %s is not executable\n' "$helper" >&2; exit 1; }

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

# A fake machine. `battery <pct>` and `mains <0|1>` are both optional, and
# leaving one out means the machine genuinely does not have it.
fixture() {
    local name="$1" battery="${2:-}" mains="${3:-}" threshold="${4:-}"
    local root="$work/$name"
    mkdir -p "$root/sys/class/power_supply"
    if [[ -n "$battery" ]]; then
        mkdir -p "$root/sys/class/power_supply/BAT0"
        printf 'Battery\n' >"$root/sys/class/power_supply/BAT0/type"
        printf '%s\n' "$battery" >"$root/sys/class/power_supply/BAT0/capacity"
        printf 'Discharging\n' >"$root/sys/class/power_supply/BAT0/status"
        [[ -n "$threshold" ]] && printf '%s\n' "$threshold" \
            >"$root/sys/class/power_supply/BAT0/charge_control_end_threshold"
    fi
    if [[ -n "$mains" ]]; then
        mkdir -p "$root/sys/class/power_supply/AC0"
        printf 'Mains\n' >"$root/sys/class/power_supply/AC0/type"
        printf '%s\n' "$mains" >"$root/sys/class/power_supply/AC0/online"
    fi
    printf '%s\n' "$root"
}

ask() {
    local root="$1"; shift
    PANAMA_HW_SYS="$root/sys" PANAMA_PATH="$repo_dir" "$helper" "$@" 2>/dev/null
}

field() { jq -r "$2" <<<"$1" 2>/dev/null; }

# ── 1. A desktop ─────────────────────────────────────────────────────────────

desktop="$(fixture desktop)"
status="$(ask "$desktop" status)"
[[ "$(field "$status" .available)" == "false" ]] \
    || note 'a machine with no battery reports one as available'
[[ "$(field "$status" .acOnline)" == "true" ]] \
    || note 'a machine with no mains supply is reported as running on battery'

paths="$(ask "$desktop" paths)"
[[ "$(field "$paths" .battery)" == "" ]] \
    || note 'a machine with no battery resolves a battery path anyway'

# ── 2. A laptop ──────────────────────────────────────────────────────────────

laptop="$(fixture laptop 64 1)"
status="$(ask "$laptop" status)"
[[ "$(field "$status" .available)" == "true" ]] || note 'a battery was not detected'
[[ "$(field "$status" .percent)" == "64" ]] \
    || note "the charge level is wrong (got $(field "$status" .percent))"
[[ "$(field "$status" .acOnline)" == "true" ]] || note 'a plugged-in laptop reads as unplugged'

unplugged="$(fixture unplugged 41 0)"
status="$(ask "$unplugged" status)"
[[ "$(field "$status" .acOnline)" == "false" ]] \
    || note 'a laptop with mains offline still reads as on wall power'

# ── 3. The charge limit appears only where it exists ─────────────────────────

paths="$(ask "$laptop" paths)"
[[ "$(field "$paths" .threshold)" == "" ]] \
    || note 'a machine without a charge threshold resolves one anyway, so the control would appear and do nothing'

limited="$(fixture limited 80 1 80)"
paths="$(ask "$limited" paths)"
[[ "$(field "$paths" .threshold)" != "" ]] \
    || note 'a machine with a charge threshold does not expose it'
[[ "$(field "$(ask "$limited" status)" .chargeLimit)" == "80" ]] \
    || note 'the charge limit is not reported'

# ── 4. The write is privileged, named, and verified ──────────────────────────

grep -q 'panama-sudo' "$helper" \
    || note 'the threshold write does not go through panama-sudo'
if grep -nE '(^|[^-[:alnum:]])sudo ' "$helper" | grep -q -v 'panama-sudo'; then
    note 'the helper calls bare sudo somewhere, so the prompt would not name the change'
fi
grep -q -- '--reason' "$helper" \
    || note 'the privileged write does not state a reason, so the prompt would not say what it changes'

# Out-of-range values are refused before any password is asked for.
PANAMA_HW_SYS="$limited/sys" PANAMA_PATH="$repo_dir" "$helper" set-threshold 10 >/dev/null 2>&1 \
    && note 'a threshold below the supported range was accepted'
PANAMA_HW_SYS="$limited/sys" PANAMA_PATH="$repo_dir" "$helper" set-threshold abc >/dev/null 2>&1 \
    && note 'a non-numeric threshold was accepted'

# ── 5. Health, where the firmware reports it ─────────────────────────────────
#
# Two sysfs spellings for the same fact, depending on whether the driver
# reports energy or charge. Both have to work, or half the laptops in the world
# get a blank tile.

with_health() {
    local name="$1" prefix="$2" full="$3" design="$4" cycles="${5:-}"
    local root
    root="$(fixture "$name" 72 1)"
    printf '%s\n' "$full" >"$root/sys/class/power_supply/BAT0/${prefix}_full"
    printf '%s\n' "$design" >"$root/sys/class/power_supply/BAT0/${prefix}_full_design"
    [[ -n "$cycles" ]] && printf '%s\n' "$cycles" >"$root/sys/class/power_supply/BAT0/cycle_count"
    printf '%s\n' "$root"
}

# A pack that has lost a tenth of its design capacity, in energy units.
energy="$(with_health energy energy 45000000 50000000 312)"
status="$(ask "$energy" status)"
[[ "$(field "$status" .healthPercent)" == "90" ]] \
    || note "health is not computed from energy_full against energy_full_design (got $(field "$status" .healthPercent))"
[[ "$(field "$status" .cycleCount)" == "312" ]] \
    || note "the charge cycle count is not reported (got $(field "$status" .cycleCount))"

# The same pack, on a driver that reports charge rather than energy.
charge="$(with_health charge charge 45000000 50000000 312)"
status="$(ask "$charge" status)"
[[ "$(field "$status" .healthPercent)" == "90" ]] \
    || note 'health is not read from the charge_full spelling, so a driver that reports charge shows no health at all'

# A pack that reports neither. Absent, null, or zero -- anything but a number
# that looks like an answer.
plain="$(ask "$laptop" status)"
for key in healthPercent cycleCount; do
    value="$(field "$plain" ".$key")"
    case "$value" in
        ""|null|0) ;;
        *) note "a battery whose firmware reports no $key was given one anyway ($value), which is a confident wrong answer about whether the hardware is dying" ;;
    esac
done

# And a machine with no battery at all invents nothing.
desktop_status="$(ask "$desktop" status)"
for key in healthPercent cycleCount; do
    value="$(field "$desktop_status" ".$key")"
    case "$value" in
        ""|null|0) ;;
        *) note "a machine with no battery reported a $key of $value" ;;
    esac
done

# A design capacity of zero would divide by it. Firmware does report this.
zeroed="$(with_health zeroed energy 45000000 0)"
status="$(ask "$zeroed" status)"
value="$(field "$status" .healthPercent)"
case "$value" in
    ""|null|0) ;;
    *) note "a zero design capacity produced a health percentage of $value" ;;
esac

# The status JSON stays parseable in every one of those cases -- an empty
# substitution would have made it valid-looking but wrong above, and invalid
# here.
for candidate in "$energy" "$charge" "$laptop" "$desktop" "$zeroed"; do
    jq -e . >/dev/null 2>&1 <<<"$(ask "$candidate" status)" \
        || note 'status stopped emitting valid JSON once the health fields were added'
done

# The service carries them through, and null-safely: `null > 0` is false in
# QML, which is what makes an absent reading hide rather than render as an
# empty tile.
for property in healthPercent cycleCount; do
    grep -q "property .*$property" "$service" \
        || note "the battery service does not expose $property, so the tile would read undefined"
done

# ── 6. The QML side hides itself ─────────────────────────────────────────────

grep -q 'property bool available' "$service" \
    || note 'the battery service has no availability flag'
grep -q 'Settings.showBattery && Battery.available' "$cluster" \
    || note 'the bar indicator does not gate on both the preference and the hardware'
# The Power page and the components it is built from. A card lifted into a
# component of its own is a normal thing to do, and every assertion below would
# quietly stop meaning anything if it only ever read PowerPage.qml.
power_surface=("$page")
for candidate in "$(dirname "$page")"/{Power,Battery,Idle}*.qml; do
    [[ -r "$candidate" && "$candidate" != "$page" ]] && power_surface+=("$candidate")
done

grep -q 'visible: Battery.available' "${power_surface[@]}" \
    || note 'the Power page battery card does not hide on a machine without one'
grep -q 'visible: Battery.chargeLimitSupported' "${power_surface[@]}" \
    || note 'the charge limit control does not hide where the firmware has none'

# The health tiles follow the same rule as everything else here: a reading the
# firmware did not give is a tile that is not drawn.
for property in healthPercent cycleCount; do
    grep -q "Battery.$property" "${power_surface[@]}" \
        || note "the Power page never shows $property, so the battery health the helper reads goes nowhere"
    grep -qE "visible: .*Battery\.$property" "${power_surface[@]}" \
        || note "the $property tile is drawn unconditionally, so a battery that reports none shows an empty one"
done

# The alias layer has to carry the key, or the binding silently reads undefined
# and the indicator never appears. This exact mistake was made writing it.
for key in showBattery batteryLowPercent batteryCriticalPercent; do
    grep -q "property .*$key" "$aliases" \
        || note "Settings.qml does not alias $key, so the binding reads undefined"
done

for key in showBattery batteryLowPercent batteryCriticalPercent batteryChargeLimit; do
    grep -q "key: \"$key\"" "$schema" || note "the schema has no $key entry"
done

# No subprocess on the polling path: the whole point of resolving paths once.
if grep -A4 'Timer {' "$service" | grep -q 'running: true' && grep -q 'Process' "$service"; then
    grep -q 'onTriggered: root.refresh()' "$service" \
        || note 'the poll timer does something other than re-read files'
fi

if (( ${#findings[@]} > 0 )); then
    printf 'battery contract: %d finding(s)\n' "${#findings[@]}" >&2
    printf '  - %s\n' "${findings[@]}" >&2
    exit 1
fi

printf 'battery contract: PASS\n'