# ==========================================================
# ISPG VISUAL GENERATOR (PATCHED STABLE VERSION)
# FILE: models/visual_generator.py
# ==========================================================
# PURPOSE:
# - Generate Flowchart PNG (Methodology)
# - Generate Results Table PNG
# - Generate Simple Bar Chart PNG (Metrics)
# - Extract Numeric Metrics from bullets
#
# IMPORTANT PATCH:
# - Use matplotlib Agg backend (NO tkinter GUI)
# - Prevent Flask threading crash: "main thread is not in main loop"
# ==========================================================

import os
import re
from typing import List, Dict, Any

# ==========================================================
# IMPORTANT FIX (MUST BE BEFORE pyplot import)
# ==========================================================
import matplotlib
matplotlib.use("Agg")

import matplotlib.pyplot as plt


# ==========================================================
# HELPER: Extract numeric values from bullet strings
# ==========================================================
def extract_numeric_metrics(bullets: List[str]) -> Dict[str, float]:
    """
    Example bullet:
    "Accuracy: 92.5%"
    "F1-score = 0.84"
    "Execution time 12.4 seconds"

    Returns dict:
    {"Accuracy":92.5, "F1-score":0.84, "Execution time":12.4}
    """

    metrics = {}

    if not bullets or not isinstance(bullets, list):
        return metrics

    for b in bullets:
        if not isinstance(b, str):
            continue

        text = b.strip()
        if not text:
            continue

        # Match key + number (float/int)
        match = re.search(r"([A-Za-z0-9\-\s]+)[:=]?\s*([0-9]+(\.[0-9]+)?)", text)

        if match:
            key = match.group(1).strip()
            val = match.group(2).strip()

            try:
                val = float(val)
            except:
                continue

            if key:
                metrics[key] = val

    return metrics


# ==========================================================
# FLOWCHART PNG GENERATOR
# ==========================================================
def generate_flowchart_png(steps: List[str], output_path: str) -> bool:
    """
    Creates a simple vertical flowchart image using matplotlib.
    """

    try:
        if not steps or not isinstance(steps, list):
            return False

        steps = [s.strip() for s in steps if isinstance(s, str) and s.strip()]
        if not steps:
            return False

        os.makedirs(os.path.dirname(output_path), exist_ok=True)

        fig, ax = plt.subplots(figsize=(8, max(6, len(steps) * 1.2)))
        ax.axis("off")

        y = 1.0
        spacing = 1.0 / (len(steps) + 1)

        for i, step in enumerate(steps):
            ax.text(
                0.5,
                y,
                f"{i+1}. {step}",
                ha="center",
                va="center",
                fontsize=12,
                fontweight="bold",
                bbox=dict(
                    boxstyle="round,pad=0.5",
                    fc="white",
                    ec="black"
                )
            )

            # Draw arrow except last
            if i < len(steps) - 1:
                ax.annotate(
                    "",
                    xy=(0.5, y - spacing * 0.7),
                    xytext=(0.5, y - spacing * 0.2),
                    arrowprops=dict(arrowstyle="->", lw=2)
                )

            y -= spacing

        plt.tight_layout()
        plt.savefig(output_path, dpi=200, bbox_inches="tight")
        plt.close(fig)

        return os.path.exists(output_path)

    except Exception as e:
        print("❌ generate_flowchart_png failed:", str(e))
        return False


# ==========================================================
# RESULTS TABLE PNG GENERATOR
# ==========================================================
def generate_results_table_png(results_tables: List[Dict[str, Any]], output_path: str) -> bool:
    """
    Generate PNG table from first detected results table.
    """

    try:
        if not results_tables or not isinstance(results_tables, list):
            return False

        table = results_tables[0]
        if not isinstance(table, dict):
            return False

        headers = table.get("headers", [])
        rows = table.get("rows", [])

        if not headers or not rows:
            return False

        os.makedirs(os.path.dirname(output_path), exist_ok=True)

        # Adjust figure height dynamically
        fig_height = max(4, min(10, len(rows) * 0.6))
        fig, ax = plt.subplots(figsize=(12, fig_height))
        ax.axis("off")

        table_plot = ax.table(
            cellText=rows,
            colLabels=headers,
            cellLoc="center",
            loc="center"
        )

        table_plot.auto_set_font_size(False)
        table_plot.set_fontsize(10)
        table_plot.scale(1.2, 1.3)

        plt.tight_layout()
        plt.savefig(output_path, dpi=200, bbox_inches="tight")
        plt.close(fig)

        return os.path.exists(output_path)

    except Exception as e:
        print("❌ generate_results_table_png failed:", str(e))
        return False


# ==========================================================
# RESULTS CHART PNG GENERATOR
# ==========================================================
def generate_results_chart_png(metrics_dict: Dict[str, float], output_path: str) -> bool:
    """
    Generate bar chart from numeric metrics.
    """

    try:
        if not metrics_dict or not isinstance(metrics_dict, dict):
            return False

        labels = list(metrics_dict.keys())[:8]
        values = []

        for k in labels:
            try:
                values.append(float(metrics_dict[k]))
            except:
                values.append(0)

        if not labels or not values:
            return False

        os.makedirs(os.path.dirname(output_path), exist_ok=True)

        fig, ax = plt.subplots(figsize=(10, 5))
        ax.bar(labels, values)

        ax.set_title("Results Metrics")
        ax.set_ylabel("Value")
        ax.tick_params(axis="x", rotation=25)

        plt.tight_layout()
        plt.savefig(output_path, dpi=200, bbox_inches="tight")
        plt.close(fig)

        return os.path.exists(output_path)

    except Exception as e:
        print("❌ generate_results_chart_png failed:", str(e))
        return False