#!/usr/bin/env bash
set -euo pipefail

# Fixes nwg-displays not auto-updating monitor/workspace configs on hyprctl reload
# in Hyprland 0.55+ Lua-based configs.
#
# Problem: require() caches modules in package.loaded, so updated monitors.lua
# is ignored on config reload. Solution: clear the cache before require().
# Also auto-generates workspaces.lua from nwg-displays' workspace.conf if missing.
# See https://lua.org/manual/5.1/manual.html#pdf-require

HYPR_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/hypr"
MAIN_LUA="$HYPR_DIR/hyprland.lua"

if [ ! -f "$MAIN_LUA" ]; then
    echo "Error: $MAIN_LUA not found. Is Hyprland 0.55+ configured with Lua?"
    exit 1
fi

# Create a backup (only if none exists)
if [ ! -f "$MAIN_LUA.bak" ]; then
    cp "$MAIN_LUA" "$MAIN_LUA.bak"
    echo "Backup saved: $MAIN_LUA.bak"
fi

patched=0

# Fix monitors
if grep -q 'require("monitors")' "$MAIN_LUA" && \
   ! grep -q 'package.loaded\["monitors"\]' "$MAIN_LUA"; then
    sed -i 's/^\s*--\s*require("monitors")/package.loaded["monitors"] = nil\nrequire("monitors")/' "$MAIN_LUA"
    echo "Patched: monitors.lua require() cache cleared"
    patched=1
else
    echo "Skipped monitors: already patched or not found"
fi

# Fix workspaces
if grep -q 'require("workspaces")' "$MAIN_LUA" && \
   ! grep -q 'package.loaded\["workspaces"\]' "$MAIN_LUA"; then
    sed -i 's/^\s*--\s*require("workspaces")/package.loaded["workspaces"] = nil\nrequire("workspaces")/' "$MAIN_LUA"
    echo "Patched: workspaces.lua require() cache cleared"
    patched=1
else
    echo "Skipped workspaces: already patched or not found"
fi

# ---------------------------------------------------------------------------
# Generate workspaces.lua from nwg-displays' workspace.conf if it's missing
# ---------------------------------------------------------------------------
WORKSPACES_LUA="$HYPR_DIR/workspaces.lua"
WORKSPACE_CONF="$HYPR_DIR/workspace.conf"

if [ ! -f "$WORKSPACES_LUA" ]; then
    if [ -f "$WORKSPACE_CONF" ]; then
        echo "Generating $WORKSPACES_LUA from $WORKSPACE_CONF ..."

        # Read header comment (first line if it starts with #)
        HEADER_LINE=$(head -1 "$WORKSPACE_CONF")
        if [[ "$HEADER_LINE" =~ ^#(.*)$ ]]; then
            COMMENT_LINE="--${BASH_REMATCH[1]}"
        fi

        {
            [ -n "${COMMENT_LINE:-}" ] && echo "$COMMENT_LINE"
            echo ""

            while IFS=',' read -ra fields; do
                line="${fields[*]}"
                [[ "$line" =~ ^#.*$ ]] && continue
                [[ -z "$line" ]] && continue

                ws_id=""
                monitor_val=""

                # Parse workspace=N
                for field in "${fields[@]}"; do
                    field="$(echo "$field" | xargs)"
                    if [[ "$field" =~ ^workspace=([0-9]+)$ ]]; then
                        ws_id="${BASH_REMATCH[1]}"
                    elif [[ "$field" =~ ^monitor:(.+)$ ]]; then
                        monitor_val="${BASH_REMATCH[1]}"
                    fi
                done

                [ -z "$ws_id" ] && continue

                # Skip disabled workspaces (monitor:false)
                [ "$monitor_val" = "false" ] && continue

                if [ "$monitor_val" = "true" ] || [ -z "$monitor_val" ]; then
                    echo "hl.workspace_rule({ workspace = \"$ws_id\" })"
                else
                    echo "hl.workspace_rule({ workspace = \"$ws_id\", monitor = \"$monitor_val\" })"
                fi
            done < <(sed 's/,\s*/,/g' "$WORKSPACE_CONF")
        } > "$WORKSPACES_LUA"
        echo "Generated $WORKSPACES_LUA"
        patched=1
    else
        echo "Warning: $WORKSPACE_CONF not found. Creating default $WORKSPACES_LUA ..."
        cat > "$WORKSPACES_LUA" <<- 'LUA'
			-- Default workspaces generated by fix-nwg-hyprland-lua.sh
			-- Workspaces 1-10 are available on all monitors
			for i = 1, 10 do
			    hl.workspace_rule({ workspace = tostring(i) })
			end
		LUA
        echo "Created default $WORKSPACES_LUA"
        patched=1
    fi
else
    echo "Skipped workspaces.lua: already exists"
fi

# When monitors.lua is missing, only warn (conversion from monitors.conf is
# non-trivial; run nwg-displays to generate it, or `cp monitors.conf monitors.lua`
# is not valid because the formats differ).
if [ ! -f "$HYPR_DIR/monitors.lua" ]; then
    echo "Warning: $HYPR_DIR/monitors.lua not found."
    echo "  Run nwg-displays to generate it, or create it manually with hl.monitor() calls."
fi

if [ "$patched" -eq 1 ]; then
    echo ""
    echo "Done! Run 'hyprctl reload' or restart Hyprland for the fix to take effect."
    echo "nwg-displays changes should now apply immediately."
else
    echo ""
    echo "No changes needed."
fi