import { Container, Graphics, Text, TextStyle } from 'pixi.js'
import { CELL_SIZE } from 'shared/board.ts'
import { theme, getThemeBackgroundImage, getThemeMode } from '../theme.ts'

const GRID_WIDTH = 1
const GRID_MAJOR_WIDTH = 2
const BORDER_WIDTH = 2
const BOARD_PAD = 1.2

const p = (gx: number, gy: number) => ({
  x: gx * CELL_SIZE,
  y: gy * CELL_SIZE,
})

export class GridRenderer {
  container: Container
  private graphics: Graphics
  private coordsContainer: Container
  private coordLabels: Text[] = []
  private lastBoardSize = 0

  constructor() {
    this.graphics = new Graphics()
    this.coordsContainer = new Container()
    this.coordsContainer.eventMode = 'none'
    this.container = new Container()
    this.container.addChild(this.graphics)
    this.container.addChild(this.coordsContainer)
  }

  private ensureCoords(boardSize: number): void {
    if (boardSize === this.lastBoardSize && this.coordLabels.length > 0) return
    this.lastBoardSize = boardSize
    this.coordsContainer.removeChildren()
    this.coordLabels.length = 0
    const style = new TextStyle({ fontFamily: 'monospace', fontSize: 9, fill: 0xc0b8e8 })

    const cols = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
    for (let c = 0; c < boardSize; c++) {
      const cx = (c + 0.5) * CELL_SIZE
      const tT = new Text({ text: cols[c], style }); tT.alpha = 0.15; tT.anchor.set(0.5, 1); tT.position.set(cx, -5); this.coordsContainer.addChild(tT); this.coordLabels.push(tT)
      const tB = new Text({ text: cols[c], style }); tB.alpha = 0.15; tB.anchor.set(0.5, 0); tB.position.set(cx, boardSize * CELL_SIZE + 5); this.coordsContainer.addChild(tB); this.coordLabels.push(tB)
    }
    for (let r = 0; r < boardSize; r++) {
      const cy = (r + 0.5) * CELL_SIZE
      const tL = new Text({ text: String(r + 1), style }); tL.alpha = 0.15; tL.anchor.set(1, 0.5); tL.position.set(-7, cy); this.coordsContainer.addChild(tL); this.coordLabels.push(tL)
      const tR = new Text({ text: String(r + 1), style }); tR.alpha = 0.15; tR.anchor.set(0, 0.5); tR.position.set(boardSize * CELL_SIZE + 7, cy); this.coordsContainer.addChild(tR); this.coordLabels.push(tR)
    }
  }

  draw(boardSize: number = 15): void {
    this.graphics.clear()

    const isGarden = getThemeMode() === 'garden'
    const hasThemeBackgroundImage = getThemeBackgroundImage() !== null
    const cellFillAlpha = hasThemeBackgroundImage ? 0.58 : 0.95

    const gridColor = theme.gridMinor
    const gridMajorColor = theme.gridMajor
    const borderColor = theme.gridBorder
    const start = 0
    const end = boardSize

    // Board shadow
    const pad = BOARD_PAD
    const sTL = p(start - pad, start - pad)
    const sBR = p(end + pad, end + pad)
    const bw = sBR.x - sTL.x
    const bh = sBR.y - sTL.y
    for (let i = 0; i < 6; i += 2) {
      this.graphics.rect(sTL.x + i, sTL.y + i, bw, bh)
      this.graphics.fill({ color: 0x000000, alpha: 0.03 + i * 0.005 })
    }

    // Cell fills (alternating board pattern)
    for (let r = start; r < end; r++) {
      for (let c = start; c < end; c++) {
        const idx = r * boardSize + c
        const isOdd = idx % 2 === 1
        const fill = isOdd ? theme.cellFillAlt : theme.cellFill
        const a = p(c, r)
        const b = p(c + 1, r + 1)
        this.graphics.rect(a.x, a.y, b.x - a.x, b.y - a.y)
        this.graphics.fill({ color: fill, alpha: cellFillAlpha })
      }
    }

    // Floor cast shadow (garden theme — stacked ellipses below board)
    if (isGarden) {
      const boardBot = boardSize * CELL_SIZE
      const boardCx = (boardSize / 2) * CELL_SIZE
      const boardHalfW = (boardSize / 2) * CELL_SIZE
      for (let i = 0; i < 6; i++) {
        const t = i / 5
        const rx = boardHalfW * (0.7 + t * 0.45)
        const ry = 2 + t * 5
        const alpha = 0.28 * (1 - t * 0.9)
        const yOff = 2 + t * 7
        this.graphics.ellipse(boardCx, boardBot + yOff, rx, ry)
        this.graphics.fill({ color: 0x000000, alpha })
      }
    }

    // Board base (3D edge — visible thickness at bottom)
    const edgeH = 10
    this.graphics.rect(sTL.x, sTL.y + edgeH, bw, bh)
    this.graphics.fill({ color: 0x000000, alpha: 0.12 })
    this.graphics.rect(sTL.x, sTL.y, bw, bh)
    this.graphics.fill({ color: 0x000000, alpha: 0.06 })

    // Grid lines — vertical
    for (let col = start; col <= end; col++) {
      const isMajor = col % 5 === 0
      const a = p(col, start)
      const b = p(col, end)
      this.graphics.moveTo(a.x, a.y)
      this.graphics.lineTo(b.x, b.y)
      this.graphics.stroke({
        width: isMajor ? GRID_MAJOR_WIDTH : GRID_WIDTH,
        color: isMajor ? gridMajorColor : gridColor,
        alpha: isMajor ? 1 : 0.6,
      })
    }

    // Grid lines — horizontal
    for (let row = start; row <= end; row++) {
      const isMajor = row % 5 === 0
      const a = p(start, row)
      const b = p(end, row)
      this.graphics.moveTo(a.x, a.y)
      this.graphics.lineTo(b.x, b.y)
      this.graphics.stroke({
        width: isMajor ? GRID_MAJOR_WIDTH : GRID_WIDTH,
        color: isMajor ? gridMajorColor : gridColor,
        alpha: isMajor ? 1 : 0.6,
      })
    }

    // Border
    const border = p(start, start)
    this.graphics.rect(border.x, border.y, (end - start) * CELL_SIZE, (end - start) * CELL_SIZE)
    this.graphics.stroke({ width: BORDER_WIDTH, color: borderColor })

    this.ensureCoords(boardSize)
    this.coordsContainer.visible = isGarden
  }
}