/**
 * SIM-12: Flussmanagement — Canvas Renderer
 *
 * Zeichnet eine Landschaft mit Fluss, Vegetation, Siedlung, Auen.
 * Alle visuellen Elemente reagieren auf den Simulationszustand.
 */

import type { State, Controls } from './logic'

export class FlussRenderer {
  private ctx: CanvasRenderingContext2D
  private w: number
  private h: number
  private time = 0

  constructor(private canvas: HTMLCanvasElement) {
    this.ctx = canvas.getContext('2d')!
    this.w = canvas.width
    this.h = canvas.height
  }

  resize(): void {
    const rect = this.canvas.getBoundingClientRect()
    const dpr = window.devicePixelRatio || 1
    this.canvas.width = rect.width * dpr
    this.canvas.height = rect.height * dpr
    this.ctx.scale(dpr, dpr)
    this.w = rect.width
    this.h = rect.height
  }

  render(state: State, controls: Controls): void {
    this.time += 0.02
    const ctx = this.ctx
    const w = this.w
    const h = this.h

    // Hintergrund — Himmel
    const skyGrad = ctx.createLinearGradient(0, 0, 0, h * 0.4)
    skyGrad.addColorStop(0, '#87CEEB')
    skyGrad.addColorStop(1, '#B0E0E6')
    ctx.fillStyle = skyGrad
    ctx.fillRect(0, 0, w, h)

    // Grund — Erde/Gras
    const groundY = h * 0.35
    const groundGrad = ctx.createLinearGradient(0, groundY, 0, h)
    const greenIntensity = Math.round(80 + state.biodiversity * 0.8)
    groundGrad.addColorStop(0, `rgb(${120 - state.soilFertility * 0.3}, ${greenIntensity}, ${60 - state.erosion * 0.3})`)
    groundGrad.addColorStop(1, `rgb(${140 - state.soilFertility * 0.2}, ${100 + state.biodiversity * 0.4}, ${70})`)
    ctx.fillStyle = groundGrad
    ctx.fillRect(0, groundY, w, h - groundY)

    // Berge im Hintergrund
    this.drawMountains(ctx, w, h)

    // Auen-Bereich (wenn freigegeben)
    if (controls.floodplainRelease > 10) {
      this.drawFloodplains(ctx, w, h, controls.floodplainRelease, state)
    }

    // Fluss zeichnen
    this.drawRiver(ctx, w, h, state, controls)

    // Deiche
    if (controls.levees > 10) {
      this.drawLevees(ctx, w, h, controls.levees)
    }

    // Hochwasser-Overlay
    if (state.floodLocal > 50) {
      this.drawFlood(ctx, w, h, state.floodLocal)
    }

    // Vegetation / Baeume (Biodiversitaet)
    this.drawVegetation(ctx, w, h, state.biodiversity, state.soilFertility)

    // Siedlung
    this.drawSettlement(ctx, w, h, state.economy, state.usableLand)

    // Felder (Landwirtschaft)
    this.drawFarms(ctx, w, h, state.soilFertility, controls.irrigation)

    // Erosionsspuren
    if (state.erosion > 40) {
      this.drawErosion(ctx, w, h, state.erosion)
    }

    // Wolken
    this.drawClouds(ctx, w, h)
  }

  private drawMountains(ctx: CanvasRenderingContext2D, w: number, h: number): void {
    const baseY = h * 0.35
    ctx.fillStyle = '#8BA89A'
    ctx.beginPath()
    ctx.moveTo(0, baseY)
    ctx.lineTo(w * 0.1, baseY - h * 0.15)
    ctx.lineTo(w * 0.2, baseY - h * 0.08)
    ctx.lineTo(w * 0.35, baseY - h * 0.2)
    ctx.lineTo(w * 0.5, baseY - h * 0.05)
    ctx.lineTo(w * 0.65, baseY - h * 0.18)
    ctx.lineTo(w * 0.8, baseY - h * 0.1)
    ctx.lineTo(w * 0.9, baseY - h * 0.14)
    ctx.lineTo(w, baseY)
    ctx.closePath()
    ctx.fill()

    // Schneedecke
    ctx.fillStyle = 'rgba(255,255,255,0.5)'
    ctx.beginPath()
    ctx.moveTo(w * 0.33, baseY - h * 0.2)
    ctx.lineTo(w * 0.35, baseY - h * 0.2)
    ctx.lineTo(w * 0.37, baseY - h * 0.17)
    ctx.lineTo(w * 0.31, baseY - h * 0.17)
    ctx.closePath()
    ctx.fill()
  }

  private drawRiver(ctx: CanvasRenderingContext2D, w: number, h: number, state: State, controls: Controls): void {
    const riverWidth = 20 + (100 - controls.straightening) * 0.15
    const meander = (100 - controls.straightening) * 0.4 // Maeander-Amplitude
    const riverY = h * 0.55

    // Flussverlauf (von links nach rechts)
    ctx.beginPath()
    ctx.moveTo(0, riverY)

    const steps = 50
    for (let i = 0; i <= steps; i++) {
      const x = (i / steps) * w
      const progress = i / steps
      const wave = Math.sin(progress * Math.PI * 3 + this.time) * meander
      const y = riverY + wave
      ctx.lineTo(x, y)
    }
    // Untere Kante (Flussbreite)
    for (let i = steps; i >= 0; i--) {
      const x = (i / steps) * w
      const progress = i / steps
      const wave = Math.sin(progress * Math.PI * 3 + this.time) * meander
      const y = riverY + wave + riverWidth
      ctx.lineTo(x, y)
    }
    ctx.closePath()

    // Flussfarbe: klar (biodiversitaet hoch) bis trueb (erosion hoch)
    const clarity = Math.max(0, Math.min(1, (state.biodiversity - state.erosion * 0.5) / 80))
    const r = Math.round(30 + (1 - clarity) * 60)
    const g = Math.round(100 + clarity * 50)
    const b = Math.round(160 + clarity * 40)
    ctx.fillStyle = `rgba(${r}, ${g}, ${b}, 0.85)`
    ctx.fill()

    // Wasseroberflaeche Glanz
    ctx.strokeStyle = 'rgba(255, 255, 255, 0.3)'
    ctx.lineWidth = 1
    for (let i = 0; i < 5; i++) {
      const sx = Math.random() * w
      const sy = riverY + Math.sin(sx / w * Math.PI * 3 + this.time) * meander + riverWidth * 0.3
      ctx.beginPath()
      ctx.moveTo(sx, sy)
      ctx.lineTo(sx + 15 + Math.random() * 20, sy - 1)
      ctx.stroke()
    }
  }

  private drawLevees(ctx: CanvasRenderingContext2D, w: number, h: number, intensity: number): void {
    const leveeH = 3 + intensity * 0.08
    const riverY = h * 0.55
    ctx.fillStyle = '#8B7355'

    // Oberer Deich
    ctx.fillRect(0, riverY - leveeH - 5, w, leveeH)
    // Unterer Deich
    ctx.fillRect(0, riverY + 30, w, leveeH)
  }

  private drawFloodplains(ctx: CanvasRenderingContext2D, w: number, h: number, intensity: number, state: State): void {
    const riverY = h * 0.55
    const extent = intensity * 0.3
    const alpha = 0.15 + intensity * 0.002

    ctx.fillStyle = `rgba(100, 180, 140, ${alpha})`
    // Aue oben
    ctx.fillRect(0, riverY - extent - 20, w, extent)
    // Aue unten
    ctx.fillRect(0, riverY + 35, w, extent)

    // Schilf in den Auen
    if (intensity > 30) {
      ctx.fillStyle = '#5A8A3E'
      for (let i = 0; i < intensity * 0.3; i++) {
        const x = (i * 47 + 20) % w
        const y = riverY - 25 - Math.random() * extent * 0.5
        this.drawReeds(ctx, x, y)
      }
    }
  }

  private drawReeds(ctx: CanvasRenderingContext2D, x: number, y: number): void {
    ctx.save()
    ctx.strokeStyle = '#4A7A2E'
    ctx.lineWidth = 1.5
    for (let i = 0; i < 3; i++) {
      const lean = Math.sin(this.time * 2 + x * 0.1) * 3
      ctx.beginPath()
      ctx.moveTo(x + i * 3, y)
      ctx.quadraticCurveTo(x + i * 3 + lean, y - 8, x + i * 3 + lean * 1.5, y - 15)
      ctx.stroke()
    }
    ctx.restore()
  }

  private drawFlood(ctx: CanvasRenderingContext2D, w: number, h: number, intensity: number): void {
    const alpha = Math.min(0.4, (intensity - 50) / 100)
    const extent = (intensity - 50) * 0.8
    const riverY = h * 0.55

    ctx.fillStyle = `rgba(70, 130, 180, ${alpha})`
    // Ueberflutung breitet sich vom Fluss aus
    ctx.fillRect(0, riverY - extent, w, extent * 2 + 30)

    // Wellenlinien
    ctx.strokeStyle = `rgba(255, 255, 255, ${alpha * 0.5})`
    ctx.lineWidth = 1
    for (let row = 0; row < 3; row++) {
      ctx.beginPath()
      const baseY = riverY - extent + row * extent * 0.6
      for (let x = 0; x < w; x += 5) {
        const y = baseY + Math.sin(x * 0.05 + this.time * 3 + row) * 3
        x === 0 ? ctx.moveTo(x, y) : ctx.lineTo(x, y)
      }
      ctx.stroke()
    }
  }

  private drawVegetation(ctx: CanvasRenderingContext2D, w: number, h: number, biodiversity: number, fertility: number): void {
    const treeCount = Math.floor(biodiversity * 0.15)
    const groundY = h * 0.35

    for (let i = 0; i < treeCount; i++) {
      const seed = i * 137.5 // goldener Winkel fuer Verteilung
      const x = (seed % w)
      const yBase = groundY + 10 + (seed * 7 % (h * 0.15))

      // Nur Baeume die nicht im Flussbereich sind
      if (yBase > h * 0.5 && yBase < h * 0.65) continue

      const treeH = 12 + (fertility * 0.1) + (i % 5) * 2
      const green = Math.round(60 + biodiversity * 0.8 + (i % 3) * 20)

      // Stamm
      ctx.fillStyle = '#6B4423'
      ctx.fillRect(x - 1.5, yBase - treeH * 0.4, 3, treeH * 0.4)

      // Krone
      ctx.fillStyle = `rgb(${40 + (i % 20)}, ${green}, ${30 + (i % 15)})`
      ctx.beginPath()
      ctx.arc(x, yBase - treeH * 0.5, treeH * 0.35, 0, Math.PI * 2)
      ctx.fill()
    }
  }

  private drawSettlement(ctx: CanvasRenderingContext2D, w: number, h: number, economy: number, usableLand: number): void {
    const houseCount = Math.floor(3 + economy * 0.08)
    const startX = w * 0.6
    const baseY = h * 0.42

    for (let i = 0; i < houseCount; i++) {
      const x = startX + (i % 4) * 30 + Math.floor(i / 4) * 15
      const y = baseY + Math.floor(i / 4) * 20
      const houseH = 12 + (economy * 0.05)

      if (x > w - 20) continue

      // Haus
      ctx.fillStyle = i < 3 ? '#D4A574' : '#C4956A'
      ctx.fillRect(x, y - houseH, 16, houseH)

      // Dach
      ctx.fillStyle = '#8B4513'
      ctx.beginPath()
      ctx.moveTo(x - 3, y - houseH)
      ctx.lineTo(x + 8, y - houseH - 8)
      ctx.lineTo(x + 19, y - houseH)
      ctx.closePath()
      ctx.fill()

      // Fenster
      ctx.fillStyle = '#FFF8DC'
      ctx.fillRect(x + 3, y - houseH + 3, 4, 4)
      ctx.fillRect(x + 9, y - houseH + 3, 4, 4)
    }
  }

  private drawFarms(ctx: CanvasRenderingContext2D, w: number, h: number, fertility: number, irrigation: number): void {
    const farmArea = h * 0.75
    const rows = Math.floor(3 + fertility * 0.04)

    for (let r = 0; r < rows; r++) {
      const y = farmArea + r * 12
      const x = w * 0.05 + r * 20

      // Feldstreifen
      const green = Math.round(100 + fertility * 0.8)
      const brown = Math.round(180 - fertility * 0.5)
      ctx.fillStyle = r % 2 === 0
        ? `rgb(${brown}, ${green}, 60)`
        : `rgb(${brown - 20}, ${Math.min(180, green + 20)}, 40)`
      ctx.fillRect(x, y, w * 0.25, 8)

      // Bewaesserungskanaele
      if (irrigation > 20) {
        ctx.strokeStyle = 'rgba(70, 130, 200, 0.4)'
        ctx.lineWidth = 1
        ctx.setLineDash([3, 3])
        ctx.beginPath()
        ctx.moveTo(x, y + 4)
        ctx.lineTo(x + w * 0.25, y + 4)
        ctx.stroke()
        ctx.setLineDash([])
      }
    }
  }

  private drawErosion(ctx: CanvasRenderingContext2D, w: number, h: number, erosion: number): void {
    const count = Math.floor((erosion - 40) * 0.2)
    ctx.fillStyle = 'rgba(139, 115, 85, 0.3)'
    for (let i = 0; i < count; i++) {
      const x = (i * 89 + 30) % w
      const y = h * 0.6 + (i * 43 % (h * 0.2))
      ctx.beginPath()
      ctx.ellipse(x, y, 8 + erosion * 0.05, 3, 0.3, 0, Math.PI * 2)
      ctx.fill()
    }
  }

  private drawClouds(ctx: CanvasRenderingContext2D, w: number, h: number): void {
    ctx.fillStyle = 'rgba(255, 255, 255, 0.7)'
    for (let i = 0; i < 3; i++) {
      const cx = (i * 250 + this.time * 15) % (w + 100) - 50
      const cy = 30 + i * 25
      ctx.beginPath()
      ctx.arc(cx, cy, 20, 0, Math.PI * 2)
      ctx.arc(cx + 15, cy - 5, 15, 0, Math.PI * 2)
      ctx.arc(cx + 30, cy, 18, 0, Math.PI * 2)
      ctx.arc(cx - 12, cy + 2, 14, 0, Math.PI * 2)
      ctx.fill()
    }
  }
}