import cv2
import numpy as np
from moviepy.editor import VideoFileClip


# ───── Effect Functions ───── #

def blur_effect(frame, steps=30, max_blur=15):
    """
    Applies a gradually increasing blur.
    """
    h, w = frame.shape[:2]
    blurred_frames = []
    for i in range(steps):
        blur_strength = int((i / (steps - 1)) * max_blur)
        if blur_strength % 2 == 0:  # Blur kernel must be odd
            blur_strength += 1
        blurred = cv2.GaussianBlur(frame, (blur_strength, blur_strength), 0)
        blurred_frames.append(blurred)
    return blurred_frames


def brightness_pulse_effect(frame, steps=30, max_change=50):
    """
    Pulses brightness up and down.
    """
    frame = frame.astype(np.float32)
    output_frames = []
    for i in range(steps):
        factor = 1 + (np.sin(i / steps * 2 * np.pi) * (max_change / 255))
        bright = np.clip(frame * factor, 0, 255).astype(np.uint8)
        output_frames.append(bright)
    return output_frames


def fade_in_effect(frame, steps=30):
    """
    Fades in the frame from black.
    """
    output_frames = []
    black = np.zeros_like(frame)
    for i in range(steps):
        alpha = i / (steps - 1)
        blended = cv2.addWeighted(frame, alpha, black, 1 - alpha, 0)
        output_frames.append(blended)
    return output_frames


def slide_in_left_effect(frame, steps=30):
    """
    Slides the frame in from the left.
    """
    h, w = frame.shape[:2]
    output_frames = []
    for i in range(steps):
        x_offset = int(w * (1 - i / (steps - 1)))
        canvas = np.zeros_like(frame)
        canvas[:, max(0, x_offset):] = frame[:, :w - max(0, x_offset)]
        output_frames.append(canvas)
    return output_frames


def rotate_effect(frame, steps=30, max_angle=15):
    """
    Rotates frame gradually.
    """
    h, w = frame.shape[:2]
    center = (w // 2, h // 2)
    output_frames = []
    for i in range(steps):
        angle = max_angle * (i / (steps - 1))
        matrix = cv2.getRotationMatrix2D(center, angle, 1.0)
        rotated = cv2.warpAffine(frame, matrix, (w, h), borderMode=cv2.BORDER_REFLECT)
        output_frames.append(rotated)
    return output_frames


def zoom_center_effect(frame, steps=30, zoom_factor=1.2):
    h, w = frame.shape[:2]
    frames = []
    for i in range(steps):
        scale = 1 + (zoom_factor - 1) * (i / (steps - 1))
        new_w, new_h = int(w / scale), int(h / scale)
        x1, y1 = (w - new_w) // 2, (h - new_h) // 2
        crop = frame[y1:y1 + new_h, x1:x1 + new_w]
        resized = cv2.resize(crop, (w, h), interpolation=cv2.INTER_LINEAR)
        frames.append(resized)
    return frames


def grayscale_effect(frame, steps=30):
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    gray_colored = cv2.cvtColor(gray, cv2.COLOR_GRAY2BGR)
    return [gray_colored] * steps


def none_effect(frame, steps=30):
    return [frame] * steps


# ───── Frame Extractor ───── #

def extract_frames_one_per_second(video_path):
    cap = cv2.VideoCapture(video_path)
    if not cap.isOpened():
        raise ValueError(f"Error opening video: {video_path}")

    fps = cap.get(cv2.CAP_PROP_FPS)
    total_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
    duration_sec = int(total_frames / fps)

    frames = []
    for sec in range(duration_sec):
        cap.set(cv2.CAP_PROP_POS_MSEC, sec * 1000)
        success, frame = cap.read()
        if success:
            frames.append(frame)
        else:
            print(f"⚠️ Skipped second {sec}")
    cap.release()
    return frames


def extract_frames_by_interval(video_path, interval_sec=1.0):
    cap = cv2.VideoCapture(video_path)
    if not cap.isOpened():
        raise ValueError(f"Error opening video: {video_path}")

    input_fps = cap.get(cv2.CAP_PROP_FPS)
    total_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
    duration_sec = total_frames / input_fps

    timestamps = np.arange(0, duration_sec, interval_sec)
    frames = []

    for t in timestamps:
        cap.set(cv2.CAP_PROP_POS_MSEC, t * 1000)
        success, frame = cap.read()
        if success:
            frames.append(frame)
        else:
            print(f"⚠️ Skipped timestamp {t:.2f}s")

    cap.release()
    return frames, duration_sec


# ───── Video Creator ───── #

# def create_effect_video(frames, output_path, fps=30, effect_fn=None, **kwargs):
#     if not frames:
#         raise ValueError("No frames provided.")
#
#     h, w = frames[0].shape[:2]
#     fourcc = cv2.VideoWriter_fourcc(*'mp4v')
#     out = cv2.VideoWriter(output_path, fourcc, fps, (w, h))
#
#     for idx, frame in enumerate(frames):
#         if effect_fn is not None:
#             effect_frames = effect_fn(frame, steps=fps, **kwargs)
#         else:
#             effect_frames = [frame] * fps
#
#         for f in effect_frames:
#             out.write(f)
#
#     out.release()
#     print(f"✅ Video saved to: {output_path}")
#
def create_effect_video(frames, output_path, duration_sec, fps=30, effect_fn=None, **kwargs):
    if not frames:
        raise ValueError("No frames provided.")

    h, w = frames[0].shape[:2]
    total_output_frames = int(duration_sec * fps)
    frames_per_input = total_output_frames // len(frames)

    fourcc = cv2.VideoWriter_fourcc(*'mp4v')
    out = cv2.VideoWriter(output_path, fourcc, fps, (w, h))

    for frame in frames:
        if effect_fn is not None:
            effect_frames = effect_fn(frame, steps=frames_per_input, **kwargs)
        else:
            effect_frames = [frame] * frames_per_input

        for f in effect_frames:
            out.write(f)

    # Add padding if needed
    actual_written = len(frames) * frames_per_input
    remaining = total_output_frames - actual_written
    if remaining > 0:
        last_frame = frames[-1]
        for _ in range(remaining):
            out.write(last_frame)

    out.release()
    print(f"✅ Video saved to: {output_path} ({duration_sec:.2f} sec @ {fps} fps)")


# ───── MAIN ───── #


def main(video_file="your_video.mp4", output_file="final_output.mp4", effect_name="Zoom Center",    interval = 5,    fps = 30):


    effect_fn, effect_kwargs = EFFECTS[effect_name]

    frames, duration = extract_frames_by_interval(video_file, interval_sec=interval)

    # Temporary video without audio
    temp_video_path = "temp_no_audio.mp4"
    create_effect_video(frames, temp_video_path, duration_sec=duration, fps=fps, effect_fn=effect_fn, **effect_kwargs)

    # Add original audio back using moviepy
    original_clip = VideoFileClip(video_file)
    processed_clip = VideoFileClip(temp_video_path)
    final_clip = processed_clip.set_audio(original_clip.audio)
    final_clip.write_videofile(output_file, codec="libx264", audio_codec="aac")

    return output_file


# ───── Usage Example ───── #
EFFECTS = {
    "Zoom Center": (zoom_center_effect, {"zoom_factor": 1.2}),
    "Grayscale": (grayscale_effect, {}),
    "Blur": (blur_effect, {"max_blur": 15}),
    "None": (none_effect, {}),
    "Brightness Pulse": (brightness_pulse_effect, {"max_change": 50}),
    "Fade In": (fade_in_effect, {}),
    "Slide In Left": (slide_in_left_effect, {}),
    "Rotate": (rotate_effect, {"max_angle": 15}),
}

if __name__ == "__main__":
    video_file = "your_video.mp4"
    output_file = "final_output.mp4"
    # fps = 30
    fps = 30
    interval = 5
    zoom_factor = 1.2

    # Available effects: zoom_center_effect, grayscale_effect, none_effect, or custom
    # chosen_effect = rotate_effect
    effect_kwargs = {}

    chosen_effect = zoom_center_effect
    # effect_kwargs = {'zoom_factor': zoom_factor}  # Optional arguments for the effect

    # frames = extract_frames_one_per_second(video_file)
    # create_effect_video(frames, output_file, fps=fps, effect_fn=chosen_effect, **effect_kwargs)

    frames, duration = extract_frames_by_interval(video_file, interval_sec=interval)
    create_effect_video(frames, output_file, duration_sec=duration, fps=fps, effect_fn=chosen_effect, **effect_kwargs)