package minesweeper

import (
	"bytes"
	"fmt"
	"image/color"

	"github.com/hajimehoshi/ebiten/examples/resources/fonts"
	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
	"github.com/hajimehoshi/ebiten/v2/inpututil"
	"github.com/hajimehoshi/ebiten/v2/text/v2"
)

type Game struct {
	Width, Height  int
	CellSize       int
	rows, columns  int
	bombPercentage int
	cells          []Cell
	firstMove      bool
	lost           bool
	won            bool
	bombIndexes    map[int]struct{}
	faceSource     *text.GoTextFaceSource
}

func NewGame(width, height, cellSize, bombPercentage int) (*Game, error) {
	s, err := text.NewGoTextFaceSource(bytes.NewReader(fonts.MPlus1pRegular_ttf))
	if err != nil {
		return nil, err
	}

	rows := width / cellSize
	columns := height / cellSize

	g := &Game{
		Width:          width,
		Height:         height,
		CellSize:       cellSize,
		rows:           rows,
		columns:        columns,
		bombPercentage: bombPercentage,
		cells:          make([]Cell, rows*columns),
		firstMove:      false,
		lost:           false,
		won:            false,
		bombIndexes:    map[int]struct{}{},
		faceSource:     s,
	}

	g.Reset()

	return g, nil
}

func (g *Game) CheckWin() {
	for _, cell := range g.cells {
		if cell.cellType != BOMB && cell.state == FLAG {
			return
		} else if cell.cellType == BOMB && cell.state != FLAG {
			return
		} else if cell.state == DARK {
			return
		}
	}

	g.won = true
	return
}

func (g *Game) HandleFirstMove(i int) {
	if !g.firstMove {
		return
	}

	indexes := make([]int, 0)

	g.applyNeighbours(i, func(index int) {
		indexes = append(indexes, index)
		r := RandomUntilNoBomb(g.rows*g.columns, g.bombIndexes)
		g.cells[r].cellType = BOMB
	})

	for _, i := range indexes {
		g.cells[i].cellType = NO_BOMB
	}

	for i := range g.cells {
		g.cells[i].bombNeighbours = g.CalcNeighbourBombs(i)
	}

	g.SetBomblessNeighboursToOpen(i)
	g.firstMove = false
}

func (g *Game) Reset() {
	cells, indexes := g.SetupCells()
	g.cells = cells
	g.bombIndexes = indexes
	g.won = false
	g.lost = false
	g.firstMove = true
}

func (g *Game) Update() error {
	if !g.won && !g.lost {
		if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonLeft) {
			x, y := ebiten.CursorPosition()
			index := g.CursorPosToIndex(x, y)
			g.HandleFirstMove(index)

			if g.cells[index].cellType == BOMB && g.cells[index].state != FLAG {
				g.lost = true
			} else if g.cells[index].state != FLAG {
				g.cells[index].state = OPEN
				if g.cells[index].bombNeighbours == 0 {
					g.SetBomblessNeighboursToOpen(index)
				}
			}
		} else if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonRight) {
			x, y := ebiten.CursorPosition()
			index := g.CursorPosToIndex(x, y)
			if g.cells[index].state == DARK {
				g.cells[index].state = FLAG
			} else if g.cells[index].state == FLAG {
				g.cells[index].state = DARK
			}
		}
	}

	if inpututil.IsKeyJustPressed(ebiten.KeyR) {
		g.Reset()
	}

	g.CheckWin()
	return nil
}

func (g *Game) Draw(screen *ebiten.Image) {
	showBombs := false
	if g.lost {
		showBombs = true
		ebitenutil.DebugPrint(screen, "Game Over!")
	} else if g.won {
		ebitenutil.DebugPrint(screen, "Game Won :) YAAY!")
		return
	}

	g.DrawCells(screen, showBombs)
}

func (g *Game) DrawCells(screen *ebiten.Image, showBombs bool) {
	for _, cell := range g.cells {
		op := &ebiten.DrawImageOptions{}
		op.GeoM.Translate(float64(cell.left), float64(cell.top))

		borderImage := ebiten.NewImage(g.CellSize, g.CellSize)
		borderImage.Fill(color.Black)

		cellImage := ebiten.NewImage(g.CellSize-2, g.CellSize-2)
		if showBombs && cell.cellType == BOMB {
			cellImage.Fill(color.RGBA{255, 0, 0, 255})
		} else {
			cellImage.Fill(MatchColor(cell.state))
		}
		borderImage.DrawImage(cellImage, nil)

		if cell.state == OPEN && cell.bombNeighbours != 0 {
			txOp := &text.DrawOptions{}
			txOp.GeoM.Translate(float64(g.CellSize-24)/2, float64(g.CellSize-24)/2)
			text.Draw(borderImage, fmt.Sprintf("%v", cell.bombNeighbours), &text.GoTextFace{Source: g.faceSource, Size: 24}, txOp)
		}

		screen.DrawImage(borderImage, op)
	}
}

func (g *Game) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
	return outsideWidth, outsideHeight
}