#education purpose
#!!atention, code can have errors, check double!
#Error: [internal] functions can only be declared in the global scope or inside classes as methods
# indie:lang_version = 4
from indie import indicator, param, plot, color, Plot
from indie.algorithms import Highest, Lowest, MutSeriesF

@indicator("Support, Resistance and Median with Trend", overlay_main_pane=True)
@param.int("length", default=22, title="Historical Length", options=[22, 44, 66])
def Main(self, length):
    # Calculate support and resistance levels
    highest_high = Highest.new(self.high, length)[0]
    lowest_low = Lowest.new(self.low, length)[0]
    
    # Adjust levels
    resistance_level = highest_high
    support_level = lowest_low
    
    # Calculate median
    median_level = (resistance_level + support_level) / 2
    
    # Trend detection
    is_uptrend = self.close[0] > median_level and self.close[1] > median_level
    is_downtrend = self.close[0] < median_level and self.close[1] < median_level
    
    # Plot levels
    @plot("Resistance", color=color.RED, width=2)
    def plot_resistance():
        return resistance_level
    
    @plot("Support", color=color.GREEN, width=2)
    def plot_support():
        return support_level
    
    @plot("Median", color=color.WHITE, width=1)
    def plot_median():
        return median_level
    
    # Trend indication
    trend_color = color.GRAY
    trend_text = "Neutral"
    if is_uptrend:
        trend_color = color.GREEN
        trend_text = "Uptrend"
    elif is_downtrend:
        trend_color = color.RED
        trend_text = "Downtrend"
    
    # Draw text box in top right corner
    self.draw_text("trend_text", trend_text, x=self.bar_index[0], y=highest_high, color=trend_color)
    
    # Projection for future periods
    projection_periods = 8
    resistance_proj = MutSeriesF.new(resistance_level)
    support_proj = MutSeriesF.new(support_level)
    median_proj = MutSeriesF.new(median_level)
    
    for i in range(1, projection_periods + 1):
        resistance_proj[0] = resistance_level
        support_proj[0] = support_level
        median_proj[0] = median_level
        
        self.draw_line("res_line_" + str(i), self.bar_index[0], resistance_proj[0], self.bar_index[0] + i, resistance_proj[0], color=color.RED, width=2)
        self.draw_line("sup_line_" + str(i), self.bar_index[0], support_proj[0], self.bar_index[0] + i, support_proj[0], color=color.GREEN, width=2)
        self.draw_line("med_line_" + str(i), self.bar_index[0], median_proj[0], self.bar_index[0] + i, median_proj[0], color=color.WHITE, width=1)