using UnityEngine;
using System;
using System.Collections;

namespace WPM {
    [Serializable]
    public class TickerTextAnimator : MonoBehaviour {

        [SerializeField]
        public TickerText tickerText;
        public WorldMapGlobe map;
        float startTime, fadeOutTime;
        TextMesh tm, tmShadow;
        bool fadeIn, fadeOut;
        float alpha, alphaShadow;
        bool blinking = false;
        int blinkingCount;
        float blinkingLapTime;
        Vector3 scale;
        TickerBand tickerBand;
        float scrollSpeed;

        void Start() {
            tm = GetComponent<TextMesh>();
            if (tickerText == null || tm == null)
                DestroyImmediate(this);

            tickerBand = map.GetComponent<WorldMapTicker>().tickerBands[tickerText.tickerLine];
            scrollSpeed = tickerBand.scrollSpeed;

            Transform t = transform.Find("shadow");
            if (t != null) {
                tmShadow = t.GetComponent<TextMesh>();
            }

            startTime = Time.time;
            fadeIn = tickerText.fadeDuration > 0;
            fadeOut = tickerText.fadeDuration > 0 && tickerText.duration > 0 && tickerBand.scrollSpeed == 0;
            if (fadeOut)
                fadeOutTime = tickerText.duration - tickerText.fadeDuration;
            alpha = tm.color.a;
            if (tmShadow != null)
                alphaShadow = tmShadow.color.a;
            blinkingCount = 0;
            blinkingLapTime = startTime;
            blinking = tickerText.blinkInterval > 0;
            scale = transform.parent.transform.localScale;

            if (tickerText.horizontalOffsetAutomatic) {
                float x = ComputeCenteredHorizontalOffset();
                transform.localPosition = new Vector3(x - 0.5f, transform.localPosition.y, transform.localPosition.z);
            }

            Update();
        }

        public void Update() {
            map.requestMapperCamShot = true;
            if (tickerText == null || tickerBand == null) {
                DestroyImmediate(gameObject);
                return;
            }

            float elapsedTime = Time.time - startTime;
            // check duration
            if (tickerBand.scrollSpeed == 0 && tickerText.duration > 0 && elapsedTime > tickerText.duration) {
                Destroy(gameObject);
                return;
            }

            float newAlpha = alpha, newAlphaShadow = alphaShadow;
            // fade
            if (fadeIn) {
                float a = Mathf.Clamp01(elapsedTime / tickerText.fadeDuration);
                newAlpha = a * alpha;
                newAlphaShadow = a * alphaShadow;
                if (elapsedTime > tickerText.fadeDuration)
                    fadeIn = false;
            }
            if (fadeOut) {
                if (elapsedTime >= fadeOutTime) {
                    float a = 1.0f - Mathf.Clamp01((elapsedTime - fadeOutTime) / tickerText.fadeDuration);
                    newAlpha = a * alpha;
                    newAlphaShadow = a * alphaShadow;
                }
            }

            // blinking
            if (blinking) {
                if (Time.time - blinkingLapTime >= tickerText.blinkInterval) {
                    blinkingLapTime = Time.time;
                    blinkingCount++;
                    if (tickerText.blinkRepetitions > 0 && blinkingCount >= tickerText.blinkRepetitions) {
                        blinking = false;
                    }
                }
                if (blinkingCount % 2 == 0) {
                    newAlpha = newAlphaShadow = 0;
                }
            }

            if (tm.color.a != newAlpha) {
                tm.color = new Color(tm.color.r, tm.color.g, tm.color.b, newAlpha);
            }
            if (tmShadow != null && tmShadow.color.a != newAlphaShadow) {
                tmShadow.color = new Color(tmShadow.color.r, tmShadow.color.g, tmShadow.color.b, newAlphaShadow);
            }

            // scrolling or auto-centering
            if (tickerText.stayOnCenter) {
                float x = ComputeCenteredHorizontalOffset();
                transform.localPosition = new Vector3(x - 0.5f, transform.localPosition.y, transform.localPosition.z);
            } else {
                scrollSpeed = tickerBand.scrollSpeed;
                if (scrollSpeed != 0) {
                    float x = transform.localPosition.x + Time.deltaTime * scrollSpeed;
                    // exits overlay?
                    float tmw = tickerText.textMeshSize.x / scale.x;
                    float max = 0.5f + tmw * 0.5f;
                    if ((x > max && scrollSpeed > 0) || (x < -max && scrollSpeed < 0)) {
                        Destroy(gameObject);
                    } else {
                        transform.localPosition = new Vector3(x, transform.localPosition.y, transform.localPosition.z);
                    }
                }
            }

        }

        float ComputeCenteredHorizontalOffset() {
            Vector3 centerLocation = map.GetCurrentMapLocation();
            Vector2 uv = Conversion.GetUVFromSpherePoint(centerLocation);
            return uv.x;
        }
    }
}