#!/usr/bin/env bash

set -u

readonly REPO="/home/Rbanh/Documents/Bevy"
readonly TARGET_DIR="$REPO/target"
readonly EDITOR_BINARY="$TARGET_DIR/debug/editor"
readonly LAUNCHER_BINARY="$TARGET_DIR/debug/project_launcher"
readonly STATE_DIR="${XDG_STATE_HOME:-$HOME/.local/state}/blacksite-editor"
readonly LOG_FILE="$STATE_DIR/launch.log"
readonly STATUS_FILE="$STATE_DIR/splash.status"
readonly SPLASH="$REPO/scripts/editor/splash.py"
readonly BUILD_PROGRESS="$REPO/scripts/editor/build_progress.py"
readonly BUILD_STORAGE="$REPO/scripts/codex/build_storage.py"

build_only=false
project_browser=false
gpu_validation=0
sdr_fallback=false
splash_pid=""
keep_splash=false

case "${1:-}" in
    --build-only) build_only=true ;;
    --launcher) project_browser=true ;;
    --gpu-validation) gpu_validation=1 ;;
    --sdr) sdr_fallback=true ;;
    "") ;;
    *)
        printf 'Unknown option: %s\n' "$1" >&2
        exit 2
        ;;
esac

if $project_browser; then
    binary="$LAUNCHER_BINARY"
    process_name="project_launcher"
    service_description="Blacksite Project Browser"
else
    binary="$EDITOR_BINARY"
    process_name="editor"
    service_description="Blacksite Editor"
fi

if ! $build_only && [[ "${BLACKSITE_EDITOR_SERVICE:-0}" != 1 ]]; then
    service_environment=(--setenv=BLACKSITE_EDITOR_SERVICE=1 --setenv=PATH)
    for variable in \
        WAYLAND_DISPLAY DISPLAY XAUTHORITY XDG_RUNTIME_DIR \
        HYPRLAND_INSTANCE_SIGNATURE DBUS_SESSION_BUS_ADDRESS \
        XDG_CURRENT_DESKTOP XDG_SESSION_DESKTOP XDG_SESSION_TYPE \
        XDG_DATA_HOME XDG_CONFIG_HOME XDG_STATE_HOME GDK_BACKEND; do
        if [[ -v "$variable" ]]; then
            service_environment+=(--setenv="$variable")
        fi
    done
    launcher_arguments=()
    [[ $# -gt 0 ]] && launcher_arguments+=("$1")
    exec systemd-run --user --collect --quiet --service-type=exec \
        --description="$service_description" \
        "${service_environment[@]}" \
        "$0" "${launcher_arguments[@]}"
fi

write_status() {
    local phase="$1"
    local detail="$2"
    local progress="$3"
    local state="${4:-running}"
    local crate_count="${5:-}"
    printf '%s\n%s\n%s\n%s\n%s\n' \
        "$phase" "$detail" "$progress" "$state" "$crate_count" >"$STATUS_FILE.tmp"
    mv "$STATUS_FILE.tmp" "$STATUS_FILE"
}

close_splash() {
    if [[ -n "$splash_pid" ]] && ! $keep_splash; then
        write_status "Editor ready" "Opening workspace" 100 close
    fi
}
trap close_splash EXIT

find_existing() {
    local pid executable
    while read -r pid; do
        [[ -n "$pid" ]] || continue
        executable="$(readlink -f "/proc/$pid/exe" 2>/dev/null || true)"
        if [[ "$executable" == "$binary" ]]; then
            printf '%s\n' "$pid"
            return 0
        fi
    done < <(pgrep -x "$process_name" 2>/dev/null || true)
    return 1
}

focus_process() {
    local pid="$1"
    if command -v hyprctl >/dev/null 2>&1; then
        hyprctl dispatch focuswindow "pid:$pid" >/dev/null 2>&1 || true
    fi
}

running_binary_is_current() {
    local pid="$1"
    local running_identity current_identity
    running_identity="$(stat -Lc '%d:%i' "/proc/$pid/exe" 2>/dev/null || true)"
    current_identity="$(stat -Lc '%d:%i' "$binary" 2>/dev/null || true)"
    [[ -n "$running_identity" && "$running_identity" == "$current_identity" ]]
}

build_current_editor() {
    write_status "Checking build storage" "Validating the managed development lane" 6
    if ! python3 "$BUILD_STORAGE" enforce --phase pre >>"$LOG_FILE" 2>&1; then
        write_status "Build storage limit reached" \
            "Open the launch log for the checked storage report" 6 error
        return 1
    fi

    python3 "$BUILD_PROGRESS" "$STATUS_FILE" "$LOG_FILE"
    local build_result=$?

    if ! python3 "$BUILD_STORAGE" enforce --phase post >>"$LOG_FILE" 2>&1; then
        printf '%s\n' \
            "warning: build-storage postflight failed; see the report above" \
            >>"$LOG_FILE"
    fi
    return "$build_result"
}

mkdir -p "$STATE_DIR"
exec 9>"$STATE_DIR/build.lock"
if ! flock -n 9; then
    exit 0
fi

: >"$LOG_FILE"
write_status "Preparing workspace" "Reading project configuration" 5

if ! $build_only; then
    GSK_RENDERER=gl python3 "$SPLASH" "$STATUS_FILE" "$LOG_FILE" &
    splash_pid=$!
fi

if ! cd "$REPO"; then
    write_status "Project unavailable" "$REPO could not be opened" 100 error
    keep_splash=true
    exit 1
fi

# Capture the process before Cargo may atomically replace the on-disk executable. A launcher click
# always checks/builds source updates first; it never silently focuses a stale process and makes the
# user believe the running editor already contains the rebuilt UI.
existing_pid=""
if ! $build_only; then
    existing_pid="$(find_existing || true)"
fi

if ! build_current_editor; then
    if $build_only; then
        tail -n 120 "$LOG_FILE" >&2
    else
        keep_splash=true
    fi
    exit 1
fi

if [[ -n "$existing_pid" ]] && kill -0 "$existing_pid" 2>/dev/null; then
    focus_process "$existing_pid"
    if running_binary_is_current "$existing_pid"; then
        write_status "Editor already open" "Focused the current development build" 100 close
    else
        write_status "Update ready" "Close and reopen the editor to activate it" 100 close
        if command -v notify-send >/dev/null 2>&1; then
            notify-send --app-name="Blacksite Editor" \
                "Blacksite update ready" \
                "Close the running editor normally, then reopen it to activate the rebuilt UI." \
                >/dev/null 2>&1 || true
        fi
    fi
    # The status above already asked the splash process to close. Prevent the EXIT trap from
    # replacing the meaningful "already open" or "update ready" result with a startup message.
    splash_pid=""
    exit 0
fi

if $build_only; then
    printf 'Blacksite editor and project browser are current.\n'
    exit 0
fi

if [[ ! -x "$binary" ]]; then
    write_status "Editor build unavailable" \
        "The managed build completed without the requested binary" 100 error
    keep_splash=true
    exit 1
fi

export RUST_BACKTRACE=1
export WGPU_VALIDATION="$gpu_validation"
if $sdr_fallback; then
    export BEVY_FPS_HDR=0
fi

export LD_LIBRARY_PATH="$TARGET_DIR/debug/deps${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
write_status "Starting editor" "Opening the current development build" 82

watch_editor_window() {
    local editor_pid="$1"
    trap - EXIT
    if command -v hyprctl >/dev/null 2>&1 && command -v jq >/dev/null 2>&1; then
        for ((attempt = 0; attempt < 300; attempt++)); do
            if ! kill -0 "$editor_pid" 2>/dev/null; then
                write_status "Editor stopped during startup" \
                    "Open the launch log for runtime details" 100 error
                return
            fi
            if hyprctl clients -j 2>/dev/null | jq -e --argjson pid "$editor_pid" \
                'any(.[]; .pid == $pid and .mapped == true)' >/dev/null; then
                write_status "Editor ready" "Opening workspace" 100
                sleep 0.4
                write_status "Editor ready" "Opening workspace" 100 close
                return
            fi
            if ((attempt == 10)); then
                write_status "Initializing renderer" "Connecting to the graphics device" 88
            elif ((attempt == 35)); then
                write_status "Loading editor scene" "Preparing the workspace" 94
            fi
            sleep 0.1
        done
    else
        write_status "Loading editor scene" "Preparing the workspace" 94
        sleep 5
        if kill -0 "$editor_pid" 2>/dev/null; then
            write_status "Editor ready" "Opening workspace" 100
            sleep 0.4
            write_status "Editor ready" "Opening workspace" 100 close
            return
        fi
    fi
    write_status "Editor is taking longer than expected" \
        "The process is still running; check the launch log" 100 error
}

# The lock protects the managed build and startup handoff, not the editor runtime. Leaving this
# descriptor inherited across `exec` prevents later build-only updates for as long as the editor is
# open.
flock -u 9
exec 9>&-
watch_editor_window "$$" &
exec "$binary" >>"$LOG_FILE" 2>&1

write_status "Editor could not be started" \
    "Open the launch log for runtime details" 100 error
keep_splash=true
exit 1