package game

import (
	"encoding/json"
	"fmt"

	"omctf.ru/block-game-backend/schema"
	"omctf.ru/block-game-backend/utils/xy"
)

type Tile struct {
	Kind string          `json:"kind"`
	Pos  xy.Point        `json:"pos"`
	Data json.RawMessage `json:"data"`
}

type Tiles struct {
	size  int
	Tiles []Tile
}

func NewTiles(size int, tiles []schema.Tile) Tiles {
	var result Tiles
	result.size = size
	for _, tile := range tiles {
		result.Tiles = append(result.Tiles, Tile{
			Kind: tile.Kind,
			Pos:  tile.Pos,
			Data: tile.Data,
		})
	}
	return result
}

func (t *Tiles) Size() int {
	return t.size
}

func (t *Tiles) inBounds(p xy.Point) bool {
	return p.X >= 0 && p.Y >= 0 && p.X < t.size && p.Y < t.size
}

func (t *Tiles) GetPlayerTile() (*Tile, error) {
	playerIdx, err := t.GetTheOnlyIdx("player")
	if err != nil {
		return nil, err
	}
	if playerIdx == -1 {
		return nil, fmt.Errorf("player not found")
	}
	return &t.Tiles[playerIdx], nil
}

func (t *Tiles) Index(tile *Tile) int {
	for i := range t.Tiles {
		if &t.Tiles[i] == tile {
			return i
		}
	}
	return -1
}

func (t *Tiles) GetTheOnlyIdx(kind string) (int, error) {
	result := -1
	for i, tile := range t.Tiles {
		if tile.Kind == kind {
			if result != -1 {
				return -1, ErrDuplicateType{}
			}
			result = i
		}
	}
	return result, nil
}

func (t *Tiles) GetTheOnly(kind string) (*Tile, error) {
	i, err := t.GetTheOnlyIdx(kind)
	if err != nil {
		return nil, err
	}
	if i == -1 {
		return nil, nil
	}
	return &t.Tiles[i], nil
}

type TilesAt []*Tile

func (t *Tiles) At(p xy.Point) TilesAt {
	var result TilesAt
	for i := range t.Tiles {
		if t.Tiles[i].Pos == p {
			result = append(result, &t.Tiles[i])
		}
	}
	return result
}

type ErrDuplicateType struct{}

func (e ErrDuplicateType) Error() string {
	return "multiple tiles of the requested type"
}

func (t TilesAt) Has(kind string) bool {
	for _, tile := range t {
		if tile.Kind == kind {
			return true
		}
	}
	return false
}

func (t TilesAt) GetTheOnlyIdx(kind string) (int, error) {
	result := -1
	for i, tile := range t {
		if tile.Kind == kind {
			if result != -1 {
				return -1, ErrDuplicateType{}
			}
			result = i
		}
	}
	return result, nil
}

func (t TilesAt) GetTheOnly(kind string) (*Tile, error) {
	i, err := t.GetTheOnlyIdx(kind)
	if err != nil {
		return nil, err
	}
	if i == -1 {
		return nil, nil
	}
	return t[i], nil
}