package game

import (
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"

	"gopkg.in/yaml.v3"
	"thehouseoficarus/internal/net"
	"thehouseoficarus/internal/player"
	"thehouseoficarus/internal/world"
)

func (g *Game) executeUndig(sess *net.Session, args []string, rawInput string) {
	if !g.checkAdmin(sess) {
		sess.WriteLine("Unknown command.")
		return
	}
	p := sess.Player
	if p == nil {
		return
	}
	if len(args) == 0 {
		sess.WriteLine("Undig which direction?")
		return
	}

	dir := g.World.ResolveExit(args[0])
	if dir == "" {
		sess.WriteLine("Invalid direction. Use n/s/e/w/ne/nw/se/sw/u/d.")
		return
	}

	curRoom, err := g.World.LoadRoom(p.RoomID)
	if err != nil {
		sess.WriteLine("Error loading current room.")
		return
	}

	exitDef, ok := curRoom.Exits[dir]
	if !ok {
		sess.WriteLine(fmt.Sprintf("There is no exit to the %s from here.", dir))
		return
	}

	targetID := exitDef.Room
	targetRoom, err := g.World.LoadRoom(targetID)
	if err != nil {
		sess.WriteLine(fmt.Sprintf("Target room %d not found.", targetID))
		return
	}

	sess.PendingUndigDir = string(dir)
	sess.PendingUndigRoom = targetID
	sess.State = net.StateUndigConfirm

	sess.WriteLine(fmt.Sprintf("You are about to DELETE Room #%d (%s) and all exits leading to it.", targetID, targetRoom.Name))
	g.listUndigOrphans(sess, targetID)
	sess.WriteLine("")
	sess.WriteLine("Undig? [y/N]")
}

func (g *Game) listUndigOrphans(sess *net.Session, targetID int) {
	roomIndex := g.World.RoomIndex()

	inbound := make(map[int]bool)
	roomsDir := filepath.Join(g.DataDir, "rooms")
	re := regexp.MustCompile(fmt.Sprintf(`\b%d\b`, targetID))
	_ = filepath.WalkDir(roomsDir, func(path string, d os.DirEntry, err error) error {
		if err != nil || d.IsDir() || filepath.Ext(path) != ".yaml" {
			return nil
		}
		data, rerr := os.ReadFile(path)
		if rerr != nil {
			return nil
		}
		if re.MatchString(string(data)) {
			idStr := strings.TrimSuffix(filepath.Base(path), ".yaml")
			if rid, serr := strconv.Atoi(idStr); serr == nil && rid != targetID {
				inbound[rid] = true
			}
		}
		return nil
	})

	if len(inbound) == 0 {
		return
	}

	var orphans []int
	for rid := range inbound {
		room, err := g.World.LoadRoom(rid)
		if err != nil {
			continue
		}
		hasOtherExit := false
		for _, exitDef := range room.Exits {
			if roomIndex[exitDef.Room] && exitDef.Room != targetID {
				hasOtherExit = true
				break
			}
		}
		if !hasOtherExit {
			orphans = append(orphans, rid)
		}
	}

	if len(orphans) > 0 {
		sess.WriteLine(g.colorize(sess, "warning",
			fmt.Sprintf("WARNING: The following rooms will become unreachable after deletion:")))
		for _, rid := range orphans {
			room, err := g.World.LoadRoom(rid)
			name := fmt.Sprintf("#%d", rid)
			if err == nil {
				name = fmt.Sprintf("#%d (%s)", rid, room.Name)
			}
			sess.WriteLine(fmt.Sprintf("  %s", name))
		}
	}
}

func (g *Game) handleUndigConfirm(sess *net.Session, input string) {
	p := sess.Player
	if p == nil {
		sess.State = net.StateGame
		g.writePrompt(sess)
		return
	}

	choice := strings.ToLower(strings.TrimSpace(input))
	dir := sess.PendingUndigDir
	targetID := sess.PendingUndigRoom
	sess.PendingUndigDir = ""
	sess.PendingUndigRoom = 0
	sess.State = net.StateGame

	if dir == "" || targetID == 0 {
		g.writePrompt(sess)
		return
	}

	if choice != "y" && choice != "yes" {
		sess.WriteLine("Undig cancelled.")
		g.writePrompt(sess)
		return
	}

	g.performUndig(sess, p, targetID)
	g.writePrompt(sess)
}

func (g *Game) performUndig(sess *net.Session, p *player.Player, targetID int) {
	targetRoom, err := g.World.LoadRoom(targetID)
	roomName := fmt.Sprintf("#%d", targetID)
	if err == nil {
		roomName = fmt.Sprintf("#%d (%s)", targetID, targetRoom.Name)
	} else {
		sess.WriteLine(fmt.Sprintf("Target room %d no longer exists.", targetID))
		return
	}

	roomsDir := filepath.Join(g.DataDir, "rooms")
	re := regexp.MustCompile(fmt.Sprintf(`\b%d\b`, targetID))
	var cleaned int
	_ = filepath.WalkDir(roomsDir, func(path string, d os.DirEntry, err error) error {
		if err != nil || d.IsDir() || filepath.Ext(path) != ".yaml" {
			return nil
		}
		data, rerr := os.ReadFile(path)
		if rerr != nil {
			return nil
		}
		if !re.MatchString(string(data)) {
			return nil
		}

		idStr := strings.TrimSuffix(filepath.Base(path), ".yaml")
		rid, serr := strconv.Atoi(idStr)
		if serr != nil || rid == targetID {
			return nil
		}

		var room world.Room
		if yerr := yaml.Unmarshal(data, &room); yerr != nil {
			return nil
		}
		if room.Exits == nil {
			return nil
		}

		changed := false
		for ed, exitDef := range room.Exits {
			if exitDef.Room == targetID {
				delete(room.Exits, ed)
				changed = true
			}
		}

		if changed {
			newData, merr := yaml.Marshal(&room)
			if merr != nil {
				return nil
			}
			if werr := os.WriteFile(path, newData, 0644); werr != nil {
				return werr
			}
			cleaned++
		}
		return nil
	})

	targetPath, ok := g.World.GetRoomPath(targetID)
	if !ok {
		sess.WriteLine(fmt.Sprintf("Room file for %d not found.", targetID))
		return
	}
	if rerr := os.Remove(targetPath); rerr != nil {
		sess.WriteLine(fmt.Sprintf("Error deleting room file: %v", rerr))
		return
	}

	g.World.RebuildRoomIndex(g.DataDir)

	if p.RoomID == targetID {
		p.RoomID = 0
	}

	for _, other := range g.Hub.AllSessions() {
		if other.Player != nil && other.Player.RoomID == targetID {
			other.Player.RoomID = p.RoomID
			if g.Hub != nil {
				g.Hub.EnterRoom(other, p.RoomID)
			}
			other.WriteLine(fmt.Sprintf("The room around you dissolves. You find yourself elsewhere."))
			g.doLook(other)
		}
	}

	g.MobStore.RemoveMobsInRoom(targetID)
	g.World.ClearRoomState(targetID)

	sess.WriteLine(fmt.Sprintf("Deleted room %s and %d exit(s) pointing to it.", roomName, cleaned))
}