#!/usr/bin/env bash

# Behavioral coverage for the QML handoff after the helper commits a restore.
# The harness has a unique shell identity, isolated XDG roots, and fake external
# consumers. It records the real SettingsBackup call order without touching the
# daily-driver shell, compositor, keymap, or wallpaper.

set -euo pipefail

repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
service="$repo_dir/config/dot/quickshell/services/SettingsBackup.qml"
harness="$repo_dir/config/dot/quickshell/settings-backup-harness.qml"
work="$(mktemp -d /tmp/panama-settings-backup-live.XXXXXX)"

fail() {
    printf 'settings backup live contract: %s\n' "$1" >&2
    exit 1
}

qs_test() {
    XDG_CONFIG_HOME="$work/config" XDG_STATE_HOME="$work/state" qs -p "$harness" "$@"
}

cleanup() {
    qs_test kill >/dev/null 2>&1 || true
    rm -rf "$work"
}
trap cleanup EXIT

# The production command boundary must remain argv-only.
rg -Fq 'actionRun.exec([root.helperPath, "save", root.serializeHomeState()]);' "$service" \
    || fail 'save does not pass live Home state as one argument'
rg -Fq 'actionRun.exec([root.helperPath, "restore", name]);' "$service" \
    || fail 'restore is not executed through an argument array'
if rg -q 'bash.*-c|sh.*-c' "$service"; then
    fail 'the restore service constructs a shell command'
fi

# The harness replaces these seams, while these mappings prove the production
# defaults still delegate to Panama's existing public service APIs.
for mapping in \
    'HomePreferences.resetHomeDefaults();' \
    'HomePreferences.initialize(ids);' \
    'HomePreferences.setAlias(id, alias);' \
    'DesktopPreferences.reload();' \
    'DesktopPreferences.set("displays", value);' \
    'Displays.currentLayout();' \
    'Displays.applyProtectedLayout(layout);' \
    'Displays.canConfirm;' \
    'Displays.confirm();' \
    'IdleLock.apply();' \
    'Displays.externalChangeBlocked = blocked;' \
    'SystemSettings.applyPersistedDisplayPolicy();' \
    'Keybinds.applyReload();' \
    'Wallpaper.applyCurrentPolicy(false);' \
    'LockScreen.regenerate();' \
    'Quickshell.reload(false);'; do
    rg -Fq "$mapping" "$service" || fail "production restore seam is missing: $mapping"
done

qs_test --daemonize >"$work/quickshell.log" 2>&1
ready=false
for _ in $(seq 1 60); do
    if qs_test ipc show 2>/dev/null | rg -q '^target settings-backup-behavior$'; then
        ready=true
        break
    fi
    sleep 0.1
done
if [[ "$ready" != true ]]; then
    sed -n '1,200p' "$work/quickshell.log" >&2
    fail 'isolated SettingsBackup harness did not start'
fi

qs_test ipc call settings-backup-behavior reset >/dev/null
payload='{"restored":"settings-20260818-010203004.json","home":{"present":true,"data":{"initialized":true,"favorites":[{"id":"light.desk","alias":"Desk"},{"id":"light.office","alias":"Office"}]}}}'
[[ "$(qs_test ipc call settings-backup-behavior apply "$payload")" == "true" ]] \
    || fail 'valid restore output was rejected'

status=""
for _ in $(seq 1 50); do
    status="$(qs_test ipc call settings-backup-behavior status)"
    jq -e '.calls[-1] == "shell.reload"' <<<"$status" >/dev/null 2>&1 && break
    sleep 0.1
done
jq -e '
    .calls == [
        "home.reset",
        "home.initialize:light.desk,light.office",
        "home.alias:light.desk=Desk",
        "home.alias:light.office=Office",
        "desktop.reload",
        "display.apply:[{\"name\":\"DP-2\",\"width\":4500,\"height\":3000,\"refreshRate\":60,\"mode\":\"4500x3000@60\",\"scale\":1.5,\"transform\":0,\"x\":-2560,\"y\":0,\"primary\":false},{\"name\":\"HDMI-A-1\",\"width\":2560,\"height\":1440,\"refreshRate\":60,\"mode\":\"2560x1440@60\",\"scale\":1,\"transform\":0,\"x\":0,\"y\":0,\"primary\":true}]",
        "display.confirm",
        "idle.apply",
        "lock.regenerate",
        "wallpaper.apply-policy",
        "keybinds.reload",
        "system.apply",
        "display.block:false",
        "shell.reload"
    ]
    and .initialized == true
    and .favorites == [
        {"id":"light.desk","alias":"Desk"},
        {"id":"light.office","alias":"Office"}
    ]
' <<<"$status" >/dev/null || fail "restore handoff order/state was wrong: $status"

# Invalid output is rejected before Home state or external consumers change.
qs_test ipc call settings-backup-behavior reset >/dev/null
invalid='{"home":{"present":true,"data":{"initialized":true,"favorites":[{"id":"light.desk","alias":"One"},{"id":"light.desk","alias":"Two"}]}}}'
[[ "$(qs_test ipc call settings-backup-behavior apply "$invalid")" == "false" ]] \
    || fail 'duplicate Home state was accepted'
status="$(qs_test ipc call settings-backup-behavior status)"
jq -e '.calls == [] and .initialized == false and .favorites == []' <<<"$status" >/dev/null \
    || fail 'invalid restore output caused partial live mutations'

# An absent Home generation uses the same ordered external handoff but leaves
# the live Home service reset rather than manufacturing an initialized store.
qs_test ipc call settings-backup-behavior reset >/dev/null
absent='{"restored":"settings-20260818-010203005.json","home":{"present":false}}'
[[ "$(qs_test ipc call settings-backup-behavior apply "$absent")" == "true" ]] \
    || fail 'absent Home restore output was rejected'
for _ in $(seq 1 50); do
    status="$(qs_test ipc call settings-backup-behavior status)"
    jq -e '.calls[-1] == "shell.reload"' <<<"$status" >/dev/null 2>&1 && break
    sleep 0.1
done
jq -e '
    .calls == [
        "home.reset",
        "desktop.reload",
        "display.apply:[{\"name\":\"DP-2\",\"width\":4500,\"height\":3000,\"refreshRate\":60,\"mode\":\"4500x3000@60\",\"scale\":1.5,\"transform\":0,\"x\":-2560,\"y\":0,\"primary\":false},{\"name\":\"HDMI-A-1\",\"width\":2560,\"height\":1440,\"refreshRate\":60,\"mode\":\"2560x1440@60\",\"scale\":1,\"transform\":0,\"x\":0,\"y\":0,\"primary\":true}]",
        "display.confirm",
        "idle.apply",
        "lock.regenerate",
        "wallpaper.apply-policy",
        "keybinds.reload",
        "system.apply",
        "display.block:false",
        "shell.reload"
    ]
    and .initialized == false
    and .favorites == []
' <<<"$status" >/dev/null || fail "absent Home handoff was wrong: $status"

# If the restored complete layout is rejected before it can be verified, the
# original persisted layout is put back and the shell is not reloaded over an
# unproven display state.
qs_test ipc call settings-backup-behavior reset >/dev/null
[[ "$(qs_test ipc call settings-backup-behavior applyDisplayFailure "$payload")" == "false" ]] \
    || fail 'a rejected restored display layout was reported as successful'
status="$(qs_test ipc call settings-backup-behavior status)"
jq -e '.calls == [
    "home.reset",
    "home.initialize:light.desk,light.office",
    "home.alias:light.desk=Desk",
    "home.alias:light.office=Office",
    "desktop.reload",
    "display.apply:[{\"name\":\"DP-2\",\"width\":4500,\"height\":3000,\"refreshRate\":60,\"mode\":\"4500x3000@60\",\"scale\":1.5,\"transform\":0,\"x\":-2560,\"y\":0,\"primary\":false},{\"name\":\"HDMI-A-1\",\"width\":2560,\"height\":1440,\"refreshRate\":60,\"mode\":\"2560x1440@60\",\"scale\":1,\"transform\":0,\"x\":0,\"y\":0,\"primary\":true}]",
    "display.protect:{\"DP-2\":{\"mode\":\"4500x3000@60\",\"scale\":1.5,\"transform\":0,\"x\":0,\"y\":0,\"primary\":true},\"HDMI-A-1\":{\"mode\":\"2560x1440@60\",\"scale\":1,\"transform\":0,\"x\":3000,\"y\":0,\"primary\":false}}",
    "display.block:false"
] and (.lastError | contains("display layout"))' <<<"$status" >/dev/null \
    || fail "rejected display restore did not retain the original layout: $status"

# Restore refuses before launching the helper while a display apply/recovery is
# active, so no snapshot can race the confirmation boundary.
qs_test ipc call settings-backup-behavior reset >/dev/null
[[ "$(qs_test ipc call settings-backup-behavior restoreWhileDisplayBusy)" == "false" ]] \
    || fail 'snapshot restore started during an active display operation'
status="$(qs_test ipc call settings-backup-behavior status)"
jq -e '.calls == [] and (.lastError | contains("display change"))' <<<"$status" >/dev/null \
    || fail "display-busy restore refusal was not clean: $status"

# ── The colour half of a display layout ─────────────────────────────────────
#
# Displays persists eleven fields per output. A restore read seven of them.
#
# The four it dropped -- VRR mode, colour profile, bit depth, SDR brightness
# and saturation, plus the mirror source -- are the ones nobody notices going
# missing, because the picture is still there and it is still the right size.
# Worse, `layoutsEqual` compared the same seven, so a snapshot whose colour
# settings differed from the live state compared EQUAL: the restore took the
# early return, decided there was nothing to apply, and reported success while
# leaving HDR off. A silent no-op that says it worked is the failure mode this
# whole codebase keeps relearning, and this is it in the one place where the
# evidence is a monitor looking slightly wrong.
#
# Both halves are asserted, because fixing either alone leaves the bug: reading
# the fields without comparing them means the restore never runs; comparing
# them without reading them means it runs and applies nothing.

full='{
  "DP-2":      {"mode":"4500x3000@60","scale":1.5,"transform":0,"x":-2560,"y":0,"primary":false,
                "vrrMode":2,"colorProfile":"hdr","bitdepth":10,"sdrBrightness":1.2,
                "sdrSaturation":0.9,"mirrorOf":""},
  "HDMI-A-1":  {"mode":"2560x1440@60","scale":1,"transform":0,"x":0,"y":0,"primary":true,
                "vrrMode":0,"colorProfile":"srgb","bitdepth":8,"sdrBrightness":1,
                "sdrSaturation":1,"mirrorOf":"DP-2"}
}'
plain='{
  "DP-2":      {"mode":"4500x3000@60","scale":1.5,"transform":0,"x":-2560,"y":0,"primary":false},
  "HDMI-A-1":  {"mode":"2560x1440@60","scale":1,"transform":0,"x":0,"y":0,"primary":true}
}'

qs_test ipc call settings-backup-behavior reset >/dev/null

restored="$(qs_test ipc call settings-backup-behavior layoutFor "$(jq -c . <<<"$full")")"
jq -e '
    (. != null) and (length == 2)
    and (.[] | select(.name == "DP-2")
         | .vrrMode == 2 and .colorProfile == "hdr" and .bitdepth == 10
           and .sdrBrightness == 1.2 and .sdrSaturation == 0.9 and .mirrorOf == "")
' <<<"$restored" >/dev/null \
    || fail "a stored layout's colour fields did not survive the trip back into a live layout: $restored"
jq -e '.[] | select(.name == "HDMI-A-1") | .mirrorOf == "DP-2" and .bitdepth == 8' \
    <<<"$restored" >/dev/null \
    || fail "the mirror source did not survive the trip back into a live layout: $restored"

# Back-compat, in the same shape Displays.isPersistedLayoutEntry uses: a record
# written before these fields existed is still a record. Refusing it would turn
# every snapshot anybody already has into one that cannot be restored.
legacy="$(qs_test ipc call settings-backup-behavior layoutFor "$(jq -c . <<<"$plain")")"
jq -e '(. != null) and (length == 2) and (.[] | select(.name == "DP-2") | .scale == 1.5)' \
    <<<"$legacy" >/dev/null \
    || fail "a stored layout without the colour fields was refused, so older snapshots cannot be restored: $legacy"

# And the comparison. Two layouts identical but for a colour profile are not
# equal -- this is the assertion the shipped behaviour FAILS, and the reason
# the restore silently did nothing.
# The two layouts travel as one object: the IPC client turns a top-level JSON
# array into one argument per element, so passing two layouts as two arguments
# arrives as four.
compare() {
    qs_test ipc call settings-backup-behavior layoutsMatch \
        "$(jq -c -n --argjson left "$1" --argjson right "$2" '{left: $left, right: $right}')"
}

drifted="$(jq -c '.[0].colorProfile = "srgb"' <<<"$restored")"
[[ "$(compare "$restored" "$drifted")" == "false" ]] \
    || fail 'layoutsEqual calls two layouts equal when their colour profiles differ, so a restore that should change the picture takes the early return and reports success'
for field in vrrMode bitdepth sdrBrightness sdrSaturation mirrorOf; do
    case "$field" in
        mirrorOf) drifted="$(jq -c --arg f "$field" '.[0][$f] = "HDMI-A-1"' <<<"$restored")" ;;
        *)        drifted="$(jq -c --arg f "$field" '.[0][$f] = 7' <<<"$restored")" ;;
    esac
    [[ "$(compare "$restored" "$drifted")" == "false" ]] \
        || fail "layoutsEqual ignores $field, so a snapshot differing only in it restores nothing"
done
[[ "$(compare "$restored" "$restored")" == "true" ]] \
    || fail 'layoutsEqual no longer calls a layout equal to itself, which would make every restore reapply the geometry it already has'

# The tolerance on the two float fields is a tolerance, not an exemption: a
# value that came back one ulp different is the same value, a value somebody
# changed is not.
nudged="$(jq -c '.[0].sdrBrightness = 1.2000001' <<<"$restored")"
[[ "$(compare "$restored" "$nudged")" == "true" ]] \
    || fail 'a float that came back with a rounding difference is treated as a change, so every restore would reapply the layout it already has'

trap - EXIT
cleanup
printf 'settings backup live contract: PASS\n'