import Phaser from 'phaser'
import { TILE_SIZE, FORESTER_ZONE_RADIUS } from '../config'
import { PLANTABLE_TILES } from '../types'
import type { TileType } from '../types'
import { stateManager } from '../StateManager'
import type { LocalAdapter } from '../NetworkAdapter'

/** Colors used for zone rendering. */
const COLOR_IN_RADIUS  = 0x44aa44  // unselected tile within radius (edit mode only)
const COLOR_ZONE_TILE  = 0x00ff44  // tile marked as part of the zone
const ALPHA_VIEW       = 0.18      // always-on zone overlay
const ALPHA_RADIUS     = 0.12      // in-radius tiles while editing
const ALPHA_ZONE_EDIT  = 0.45      // zone tiles while editing

export class ForesterZoneSystem {
  private scene: Phaser.Scene
  private adapter: LocalAdapter

  /** Graphics layer for the always-visible zone overlay. */
  private zoneGraphics!: Phaser.GameObjects.Graphics
  /** Graphics layer for the edit-mode radius/tile overlay. */
  private editGraphics!: Phaser.GameObjects.Graphics

  /** Building ID currently being edited, or null when not in edit mode. */
  private editBuildingId: string | null = null

  /**
   * Callback invoked after a tile toggle so callers can react (e.g. refresh the panel).
   * Receives the updated zone tiles array.
   */
  onZoneChanged?: (buildingId: string, tiles: string[]) => void

  /**
   * Callback invoked when the user exits edit mode (right-click or programmatic close).
   * UIScene listens to this to close the zone edit indicator.
   */
  onEditEnded?: () => void

  /**
   * @param scene   - The Phaser scene this system belongs to
   * @param adapter - Network adapter for dispatching state actions
   */
  constructor(scene: Phaser.Scene, adapter: LocalAdapter) {
    this.scene   = scene
    this.adapter = adapter
  }

  /** Creates the graphics layers and registers the pointer listener. */
  create(): void {
    this.zoneGraphics = this.scene.add.graphics().setDepth(3)
    this.editGraphics = this.scene.add.graphics().setDepth(4)

    this.scene.input.on('pointerdown', (ptr: Phaser.Input.Pointer) => {
      if (!this.editBuildingId) return
      if (ptr.rightButtonDown()) {
        this.exitEditMode()
        return
      }
      this.handleTileClick(ptr.worldX, ptr.worldY)
    })
  }

  /**
   * Redraws all zone overlays for every forester hut in the current state.
   * Should be called whenever the zone data changes.
   */
  refreshOverlay(): void {
    this.zoneGraphics.clear()
    const state = stateManager.getState()
    for (const zone of Object.values(state.world.foresterZones)) {
      for (const key of zone.tiles) {
        const [tx, ty] = key.split(',').map(Number)
        this.zoneGraphics.fillStyle(COLOR_ZONE_TILE, ALPHA_VIEW)
        this.zoneGraphics.fillRect(tx * TILE_SIZE, ty * TILE_SIZE, TILE_SIZE, TILE_SIZE)
      }
    }
  }

  /**
   * Activates zone-editing mode for the given forester hut.
   * Draws the radius indicator and zone tiles in edit colors.
   * @param buildingId - ID of the forester_hut building to edit
   */
  startEditMode(buildingId: string): void {
    this.editBuildingId = buildingId
    this.drawEditOverlay()
  }

  /**
   * Deactivates zone-editing mode and clears the edit overlay.
   * Triggers the onEditEnded callback.
   */
  exitEditMode(): void {
    if (!this.editBuildingId) return
    this.editBuildingId = null
    this.editGraphics.clear()
    this.onEditEnded?.()
  }

  /** Returns true when the zone editor is currently active. */
  isEditing(): boolean {
    return this.editBuildingId !== null
  }

  /** Destroys all graphics objects. */
  destroy(): void {
    this.zoneGraphics.destroy()
    this.editGraphics.destroy()
  }

  // ─── Private helpers ──────────────────────────────────────────────────────

  /**
   * Handles a left-click during edit mode.
   * Toggles the clicked tile in the zone if it is within radius and plantable.
   * @param worldX - World pixel X of the pointer
   * @param worldY - World pixel Y of the pointer
   */
  private handleTileClick(worldX: number, worldY: number): void {
    const id = this.editBuildingId
    if (!id) return

    const state    = stateManager.getState()
    const building = state.world.buildings[id]
    if (!building) { this.exitEditMode(); return }

    const tileX = Math.floor(worldX / TILE_SIZE)
    const tileY = Math.floor(worldY / TILE_SIZE)

    // Chebyshev distance — must be within radius
    const dx = Math.abs(tileX - building.tileX)
    const dy = Math.abs(tileY - building.tileY)
    if (Math.max(dx, dy) > FORESTER_ZONE_RADIUS) return

    const zone = state.world.foresterZones[id]
    if (!zone) return

    const key   = `${tileX},${tileY}`
    const idx   = zone.tiles.indexOf(key)
    const tiles = idx >= 0
      ? zone.tiles.filter(t => t !== key)   // remove
      : [...zone.tiles, key]                 // add

    this.adapter.send({ type: 'FORESTER_ZONE_UPDATE', buildingId: id, tiles })
    this.refreshOverlay()
    this.drawEditOverlay()
    this.onZoneChanged?.(id, tiles)
  }

  /**
   * Redraws the edit-mode overlay showing the valid radius and current zone tiles.
   * Only called while editBuildingId is set.
   */
  private drawEditOverlay(): void {
    this.editGraphics.clear()
    const id = this.editBuildingId
    if (!id) return

    const state    = stateManager.getState()
    const building = state.world.buildings[id]
    if (!building) return

    const zone       = state.world.foresterZones[id]
    const zoneSet    = new Set(zone?.tiles ?? [])
    const r          = FORESTER_ZONE_RADIUS

    for (let dy = -r; dy <= r; dy++) {
      for (let dx = -r; dx <= r; dx++) {
        const tx  = building.tileX + dx
        const ty  = building.tileY + dy
        const key = `${tx},${ty}`

        // Only draw on plantable terrain
        const tileType = state.world.tiles[ty * 512 + tx] as TileType
        if (!PLANTABLE_TILES.has(tileType)) continue

        if (zoneSet.has(key)) {
          this.editGraphics.fillStyle(COLOR_ZONE_TILE, ALPHA_ZONE_EDIT)
          this.editGraphics.strokeRect(tx * TILE_SIZE, ty * TILE_SIZE, TILE_SIZE, TILE_SIZE)
        } else {
          this.editGraphics.fillStyle(COLOR_IN_RADIUS, ALPHA_RADIUS)
        }
        this.editGraphics.fillRect(tx * TILE_SIZE, ty * TILE_SIZE, TILE_SIZE, TILE_SIZE)
      }
    }

    // Draw a subtle border around the entire radius square
    const bx = (building.tileX - r) * TILE_SIZE
    const by = (building.tileY - r) * TILE_SIZE
    const bw = (2 * r + 1) * TILE_SIZE
    this.editGraphics.lineStyle(1, COLOR_ZONE_TILE, 0.4)
    this.editGraphics.strokeRect(bx, by, bw, bw)
  }
}