#!/usr/bin/env bash

set -euo pipefail

repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
component="$repo_dir/config/dot/quickshell/modules/settings/DisplayArrangement.qml"
page="$repo_dir/config/dot/quickshell/modules/settings/DisplaysPage.qml"
harness="$repo_dir/config/dot/quickshell/display-arrangement-harness.qml"

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

[[ -f "$component" ]] || fail 'DisplayArrangement.qml is missing'
for contract in \
    'required property var displayService' \
    'property var draftLayout:' \
    'function setDraftPosition(' \
    'function nudge(' \
    'function applyDraft(' \
    'function makePrimary(' \
    'Accessible.name: "Move "' \
    'DragHandler {' \
    'Keys.onPressed:'; do
    rg -Fq "$contract" "$component" \
        || fail "arrangement interaction is missing: $contract"
done
rg -Fq 'DisplayArrangement {' "$page" \
    || fail 'Displays page does not expose the arrangement canvas'
rg -Fq 'visible: Displays.monitors.length > 1' "$page" \
    || fail 'arrangement is shown for a single display'

state_home="$(mktemp -d /tmp/panama-display-arrangement-state.XXXXXX)"
harness_pid=""
cleanup() {
    [[ "$harness_pid" =~ ^[0-9]+$ ]] && kill "$harness_pid" 2>/dev/null || true
    rm -rf "$state_home"
}
trap cleanup EXIT

XDG_STATE_HOME="$state_home" qs -p "$harness" --daemonize >/dev/null
for _ in $(seq 1 60); do
    harness_pid="$(qs list --all 2>/dev/null | awk -v expected="$harness" '
        /^Instance / {pid=""} /^[[:space:]]*Process ID:/ {pid=$3}
        /^[[:space:]]*Config path:/ {path=$0; sub(/^[[:space:]]*Config path: /,"",path); if(path==expected) print pid}' | head -1)"
    [[ "$harness_pid" =~ ^[0-9]+$ ]] \
        && XDG_STATE_HOME="$state_home" qs -p "$harness" ipc --pid "$harness_pid" show 2>/dev/null \
            | rg -q '^target display-arrangement-test$' && break
    sleep 0.1
done
[[ "$harness_pid" =~ ^[0-9]+$ ]] || fail 'arrangement harness did not start'

ipc() {
    XDG_STATE_HOME="$state_home" qs -p "$harness" ipc --pid "$harness_pid" \
        call display-arrangement-test "$@"
}

wide="$(ipc status 800)"
narrow="$(ipc status 500)"
for snapshot in "$wide" "$narrow"; do
    jq -e '(.rects | length) == 2
        and .scale > 0
        and (.rects[0].width / .rects[0].height - 1.5 | fabs) < 0.0001
        and (.rects[1].width / .rects[1].height - (2560 / 1440) | fabs) < 0.0001' \
        <<<"$snapshot" >/dev/null \
        || fail "canvas lost monitor geometry at a supported width: $snapshot"
done

drag="$(ipc dragFixture)"
jq -e '.[0].x == 0 and .[1].x == 3000' <<<"$drag" >/dev/null \
    || fail "drag release did not snap and apply the complete layout: $drag"

keyboard="$(ipc keyboardFixture)"
jq -e '.afterArrow == 2990 and .afterShiftArrow == 2890' <<<"$keyboard" >/dev/null \
    || fail "keyboard movement did not use 10/100 logical-pixel steps: $keyboard"

primary="$(ipc primaryFixture)"
jq -e '. == [
    {"name":"DP-2","x":-3000,"y":0,"primary":false},
    {"name":"HDMI-A-1","x":0,"y":0,"primary":true}
]' <<<"$primary" >/dev/null \
    || fail "Make primary did not normalize the selected output to 0,0: $primary"

printf 'display arrangement contract: PASS\n'