package main

import (
	"encoding/json"
	"fmt"
	"strconv"
)

func simulateChunk(sessionID string, inputs []Input, totalTicks int, vals map[string]string) (bool, int, []ActiveObstacle) {
	posY := parseOr(vals["pos_y"], PlayerYBase)
	velY := parseOr(vals["vel_y"], 0.0)
	score := int(parseOr(vals["score"], 0))
	rngStateVal, _ := strconv.ParseInt(vals["rng_state"], 10, 64)

	godLives := int(parseOr(vals["p_god_lives"], 0))
	hasBat := vals["p_has_bat"] == "1"
	bootTicks := int(parseOr(vals["p_boot_ticks"], 0))

	rng := NewRNG(rngStateVal)

	var obstacles []ActiveObstacle
	if val, ok := vals["obstacles"]; ok && val != "" {
		json.Unmarshal([]byte(val), &obstacles)
	} else {
		obstacles = []ActiveObstacle{}
	}

	playerDead := false

	for i := 0; i < totalTicks; i++ {
		currentSpeed := BaseSpeed + (float64(score) / 1000)
		if currentSpeed > 10.0 {
			currentSpeed = 10.0
		}

		currentJumpPower := JumpPower
		if bootTicks > 0 {
			currentJumpPower = HighJumpPower
			bootTicks--
		}

		didJump := false
		isCrouching := false
		for _, inp := range inputs {
			if inp.Tick == i {
				if inp.Act == "JUMP" {
					didJump = true
				}
				if inp.Act == "DUCK" {
					isCrouching = true
				}
			}
		}

		isGrounded := posY >= PlayerYBase-1.0
		currentHeight := PlayerHeight
		if isCrouching {
			currentHeight = PlayerHeight / 2
			if !isGrounded {
				velY += 2.0
			}
		}

		if didJump && isGrounded && !isCrouching {
			velY = currentJumpPower
		}

		velY += Gravity
		posY += velY
		if posY > PlayerYBase {
			posY = PlayerYBase
			velY = 0
		}

		hitboxY := posY
		if isCrouching {
			hitboxY = posY + (PlayerHeight - currentHeight)
		}

		nextObstacles := []ActiveObstacle{}
		rightmostX := 0.0

		for _, obs := range obstacles {
			obs.X -= currentSpeed

			if obs.X+obs.Width < -50.0 {
				continue
			}

			paddingX := 10.0
			realRightEdge := obs.X + obs.Width - paddingX

			if realRightEdge < 55.0 {
				nextObstacles = append(nextObstacles, obs)
				if obs.X+obs.Width > rightmostX {
					rightmostX = obs.X + obs.Width
				}
				continue
			}

			paddingY_Top := 10.0
			if obs.Type == "teacher" {
				paddingY_Top = 25.0
			}

			pLeft, pRight := 50.0+paddingX, 50.0+30.0-paddingX
			pTop, pBottom := hitboxY+paddingY_Top, hitboxY+currentHeight-5.0

			oLeft := obs.X + paddingX
			oRight := obs.X + obs.Width - paddingX + currentSpeed
			oTop, oBottom := obs.Y+paddingY_Top, obs.Y+obs.Height-5.0

			isCollision := pRight > oLeft && pLeft < oRight && pBottom > oTop && pTop < oBottom

			if isCollision {
				if obs.Type == "coin" {
					score += 2000
					continue
				} else if obs.Type == "powerup" {
					if obs.ID == "p_god" {
						godLives = 3
					}
					if obs.ID == "p_bat" {
						hasBat = true
					}
					if obs.ID == "p_boot" {
						bootTicks = 600
					}
					continue
				} else {
					if hasBat && obs.Type == "teacher" {
						hasBat = false
						continue
					}
					if godLives > 0 {
						godLives--
						continue
					}
					playerDead = true
				}
			}

			nextObstacles = append(nextObstacles, obs)
			if obs.X+obs.Width > rightmostX {
				rightmostX = obs.X + obs.Width
			}
		}
		obstacles = nextObstacles

		if rightmostX < GameWidth-10.0 {
			rawGap := 400.0 + rng.NextRange(0, 500)
			gap := float64(int(rawGap))
			spawnX := rightmostX + gap
			if spawnX < GameWidth {
				spawnX = GameWidth
			}

			isBossPhase := (score % 1500) > 1200
			var possibleDefs []ObstacleDef

			for _, d := range defaultConfig.Obstacles {
				if isBossPhase {
					if d.ID == "principal" || d.ID == "trashcan" {
						possibleDefs = append(possibleDefs, d)
					}
				} else {
					if d.ID == "principal" {
						continue
					}
					if d.ID == "eraser" && score < 500 {
						continue
					}
					possibleDefs = append(possibleDefs, d)
				}
			}

			def := rng.PickDef(possibleDefs)

			if def != nil && def.CanTalk {
				if rng.NextFloat() > 0.7 {
					rng.NextFloat()
				}
			}

			if def != nil {
				if def.Type == "powerup" && rng.NextFloat() > 0.1 {
					def = nil
				}

				if def != nil {
					spawnY := GroundY - def.Height - def.YOffset
					obstacles = append(obstacles, ActiveObstacle{
						ID:     def.ID,
						Type:   def.Type,
						X:      spawnX,
						Y:      spawnY,
						Width:  def.Width,
						Height: def.Height,
					})
				}
			}
		}

		if !playerDead {
			score++
		} else {
			break
		}
	}

	obsJson, _ := json.Marshal(obstacles)
	batStr := "0"
	if hasBat {
		batStr = "1"
	}

	rdb.HSet(ctx, "session:"+sessionID, map[string]interface{}{
		"score":        score,
		"pos_y":        fmt.Sprintf("%f", posY),
		"vel_y":        fmt.Sprintf("%f", velY),
		"rng_state":    rng.State,
		"obstacles":    string(obsJson),
		"p_god_lives":  godLives,
		"p_has_bat":    batStr,
		"p_boot_ticks": bootTicks,
	})

	return playerDead, score, obstacles
}

func parseOr(s string, def float64) float64 {
	if s == "" {
		return def
	}
	v, err := strconv.ParseFloat(s, 64)
	if err != nil {
		return def
	}
	return v
}