import streamlit as st
import dspy
import pandas as pd
import re
import httpx
import json
from openai import OpenAI
from st_aggrid import AgGrid, GridOptionsBuilder, GridUpdateMode, DataReturnMode
from typing import Optional, Dict, Any
import os

# --- Page Configuration ---
st. set_page_config(
    layout="wide",
    page_title="GEPA Regex Optimizer",
    page_icon="🧬",
    initial_sidebar_state="expanded"
)

# --- Session State Initialization ---
DEFAULT_STATE = {
    'dataset': None,
    'optimized_program': None,
    'optimization_history': [],
    'config':  {
        'model_name': 'gpt-4o',
        'api_key': '',
        'base_url': 'https://api.openai.com/v1',
        'timeout': 30,
        'max_retries': 3,
        'temperature': 0.7,
        'max_tokens': 1024,
    },
    'gepa_config': {
        'num_iterations': 5,
        'num_candidates': 3,
        'early_stopping_threshold':  0.95,
    },
    'prompts': {
        'system_instruction': "You are a Regex Expert. Given the input text, provide a high-precision Python regex pattern to extract the target text.",
        'gepa_meta_prompt':  "Focus on precision.  If the feedback says the match was too broad, use more specific character classes or anchors. If it missed the target, suggest more flexible patterns.",
        'output_description': "A Python-compatible regular expression",
    },
    'train_test_split': 0.8,
    'regex_flags': [],
}

for key, value in DEFAULT_STATE.items():
    if key not in st.session_state:
        st.session_state[key] = value


# --- Configuration Manager ---
class ConfigManager:
    """Manages application configuration with persistence."""
    
    CONFIG_FILE = "gepa_config.json"
    
    @staticmethod
    def save_config():
        """Save current configuration to file."""
        config_data = {
            'config': st.session_state. config,
            'gepa_config': st.session_state. gepa_config,
            'prompts': st.session_state.prompts,
            'train_test_split': st.session_state. train_test_split,
            'regex_flags': st. session_state.regex_flags,
        }
        try:
            with open(ConfigManager.CONFIG_FILE, 'w') as f:
                json.dump(config_data, f, indent=2)
            return True
        except Exception as e:
            st.error(f"Failed to save config: {e}")
            return False
    
    @staticmethod
    def load_config():
        """Load configuration from file."""
        try: 
            if os.path.exists(ConfigManager.CONFIG_FILE):
                with open(ConfigManager.CONFIG_FILE, 'r') as f:
                    config_data = json.load(f)
                for key, value in config_data. items():
                    if key in st.session_state:
                        if isinstance(value, dict):
                            st. session_state[key].update(value)
                        else: 
                            st. session_state[key] = value
                return True
        except Exception as e: 
            st.warning(f"Failed to load config: {e}")
        return False
    
    @staticmethod
    def reset_to_defaults():
        """Reset all configuration to defaults."""
        for key, value in DEFAULT_STATE.items():
            if key not in ['dataset', 'optimized_program', 'optimization_history']: 
                st.session_state[key] = value. copy() if isinstance(value, (dict, list)) else value


# --- LLM Setup ---
def setup_dspy() -> bool:
    """Configure DSPy with current settings."""
    config = st.session_state. config
    try:
        http_client = httpx.Client(
            timeout=config['timeout'],
            limits=httpx.Limits(max_retries=config['max_retries'])
        )
        
        custom_openai_client = OpenAI(
            api_key=config['api_key'] or os.getenv("OPENAI_API_KEY", "empty"),
            base_url=config['base_url'] or None,
            http_client=http_client
        )
        
        lm = dspy.LM(
            model=config['model_name'],
            client=custom_openai_client,
            temperature=config['temperature'],
            max_tokens=config['max_tokens']
        )
        dspy.configure(lm=lm)
        return True
    except Exception as e:
        st. error(f"LLM Configuration Error: {e}")
        return False


# --- Metric Function ---
def create_regex_metric(flags: list):
    """Factory function to create metric with configurable regex flags."""
    
    compiled_flags = 0
    for flag in flags:
        compiled_flags |= getattr(re, flag, 0)
    
    def regex_metric_with_feedback(example, prediction, trace=None):
        """GEPA Metric with rich feedback for regex optimization."""
        target = example. ground_truth. strip()
        raw_text = example. raw_text
        pred_pattern = getattr(prediction, 'regex_pattern', '').strip()

        # Handle missing output
        if not pred_pattern:
            feedback = (
                f"No regex pattern provided. Target text: '{target}'.  "
                "Please output a valid Python regex string."
            )
            return dspy. Prediction(score=0.0, feedback=feedback)

        # Syntax validation
        try: 
            compiled = re.compile(pred_pattern, compiled_flags)
        except re.error as e:
            feedback = (
                f"Invalid regex:  '{pred_pattern}'.  "
                f"Error: {str(e)}. Check syntax and escape characters."
            )
            return dspy. Prediction(score=0.0, feedback=feedback)

        # Match evaluation
        match = compiled.search(raw_text)
        extracted = match.group(0) if match else ""
        
        if extracted == target:
            return dspy.Prediction(
                score=1.0, 
                feedback=f"Perfect match! Correctly extracted '{target}'."
            )
        
        # Failure analysis
        score = 0.0
        feedback = f"Pattern '{pred_pattern}' produced incorrect result.\n"
        
        if not match:
            feedback += f"NO MATCH found. Target: '{target}'."
        elif target in extracted:
            score = 0.3
            feedback += (
                f"TOO BROAD:  Extracted '{extracted}' contains target '{target}' "
                "plus extra characters. Use stricter boundaries or non-greedy quantifiers."
            )
        elif extracted in target:
            score = 0.3
            feedback += (
                f"TOO NARROW:  Extracted '{extracted}' but target is '{target}'.  "
                "Make pattern more inclusive."
            )
        else:
            feedback += f"WRONG MATCH: Got '{extracted}' instead of '{target}'."

        feedback += "\nAnalyze the target structure to isolate it uniquely."
        return dspy.Prediction(score=score, feedback=feedback)
    
    return regex_metric_with_feedback


# --- DSPy Program ---
class RegexSignature(dspy. Signature):
    """Dynamic signature for regex generation."""
    raw_text = dspy. InputField()
    regex_pattern = dspy.OutputField()


class RegexGenerator(dspy.Module):
    """Configurable regex generation module."""
    
    def __init__(self, doc:  str, output_desc: str):
        super().__init__()
        self.predictor = dspy.Predict(RegexSignature)
        self.predictor.signature.__doc__ = doc
        self.predictor.signature.regex_pattern. desc = output_desc

    def forward(self, raw_text:  str):
        return self. predictor(raw_text=raw_text)


# --- Sidebar Configuration ---
def render_sidebar():
    """Render the configuration sidebar."""
    with st.sidebar:
        st.title("⚙️ Configuration")
        
        # Config management buttons
        col1, col2, col3 = st.columns(3)
        with col1:
            if st.button("💾 Save", use_container_width=True):
                if ConfigManager.save_config():
                    st.success("Saved!")
        with col2:
            if st.button("📂 Load", use_container_width=True):
                if ConfigManager.load_config():
                    st.success("Loaded!")
                    st.rerun()
        with col3:
            if st.button("🔄 Reset", use_container_width=True):
                ConfigManager.reset_to_defaults()
                st.rerun()
        
        st.divider()
        
        # LLM Configuration
        with st.expander("🤖 LLM Settings", expanded=True):
            st.session_state.config['model_name'] = st.text_input(
                "Model Name",
                value=st.session_state.config['model_name'],
                help="e.g., gpt-4o, gpt-3.5-turbo, claude-3-opus"
            )
            
            st.session_state.config['api_key'] = st.text_input(
                "API Key",
                value=st.session_state.config['api_key'],
                type="password",
                help="Leave empty to use OPENAI_API_KEY env var"
            )
            
            st.session_state.config['base_url'] = st.text_input(
                "Base URL",
                value=st.session_state.config['base_url'],
                help="Custom API endpoint (e.g., for Azure, local models)"
            )
            
            col1, col2 = st.columns(2)
            with col1:
                st.session_state.config['timeout'] = st.number_input(
                    "Timeout (s)",
                    min_value=5,
                    max_value=300,
                    value=st.session_state.config['timeout']
                )
            with col2:
                st.session_state.config['max_retries'] = st.number_input(
                    "Max Retries",
                    min_value=0,
                    max_value=10,
                    value=st.session_state.config['max_retries']
                )
            
            col1, col2 = st.columns(2)
            with col1:
                st.session_state.config['temperature'] = st.slider(
                    "Temperature",
                    min_value=0.0,
                    max_value=2.0,
                    value=st. session_state.config['temperature'],
                    step=0.1
                )
            with col2:
                st.session_state.config['max_tokens'] = st.number_input(
                    "Max Tokens",
                    min_value=64,
                    max_value=8192,
                    value=st.session_state.config['max_tokens']
                )
        
        # GEPA Optimizer Settings
        with st. expander("🧬 GEPA Optimizer", expanded=False):
            st.session_state.gepa_config['num_iterations'] = st.slider(
                "Iterations",
                min_value=1,
                max_value=20,
                value=st. session_state.gepa_config['num_iterations'],
                help="Number of optimization iterations"
            )
            
            st.session_state. gepa_config['num_candidates'] = st.slider(
                "Candidates per Iteration",
                min_value=1,
                max_value=10,
                value=st.session_state.gepa_config['num_candidates'],
                help="Number of candidate patterns to evaluate"
            )
            
            st. session_state.gepa_config['early_stopping_threshold'] = st.slider(
                "Early Stopping Threshold",
                min_value=0.5,
                max_value=1.0,
                value=st.session_state.gepa_config['early_stopping_threshold'],
                step=0.05,
                help="Stop if this score is reached"
            )
        
        # Prompt Configuration
        with st.expander("📝 Prompts", expanded=False):
            st.session_state.prompts['system_instruction'] = st.text_area(
                "System Instruction",
                value=st.session_state.prompts['system_instruction'],
                height=100,
                help="Initial instruction for regex generation"
            )
            
            st.session_state. prompts['gepa_meta_prompt'] = st.text_area(
                "GEPA Evolution Prompt",
                value=st.session_state.prompts['gepa_meta_prompt'],
                height=100,
                help="Instructions for GEPA's prompt evolution"
            )
            
            st.session_state. prompts['output_description'] = st. text_input(
                "Output Field Description",
                value=st.session_state.prompts['output_description'],
                help="Description for the regex output field"
            )
        
        # Regex Configuration
        with st. expander("🔧 Regex Options", expanded=False):
            flag_options = ['IGNORECASE', 'MULTILINE', 'DOTALL', 'VERBOSE', 'ASCII']
            st.session_state. regex_flags = st.multiselect(
                "Regex Flags",
                options=flag_options,
                default=st.session_state. regex_flags,
                help="Python regex flags to apply"
            )
        
        # Data Split Configuration
        with st.expander("📊 Data Settings", expanded=False):
            st.session_state.train_test_split = st.slider(
                "Train/Validation Split",
                min_value=0.5,
                max_value=0.95,
                value=st.session_state.train_test_split,
                step=0.05,
                help="Proportion of data for training"
            )


# --- Main Application Tabs ---
def render_data_ingestion_tab():
    """Render the data ingestion tab."""
    st.header("📥 Data Ingestion & Annotation")
    
    col1, col2 = st.columns([2, 1])
    
    with col1:
        uploaded = st.file_uploader(
            "Upload Dataset",
            type=["csv", "json", "xlsx"],
            help="CSV/JSON/Excel with 'text' column (ground_truth optional)"
        )
    
    with col2:
        st.markdown("**Expected Format:**")
        st.code("text,ground_truth\n'Sample text','expected'", language="csv")
    
    if uploaded: 
        # Load based on file type
        try:
            if uploaded.name.endswith('.csv'):
                df = pd.read_csv(uploaded)
            elif uploaded.name. endswith('.json'):
                df = pd.read_json(uploaded)
            else:
                df = pd.read_excel(uploaded)
            
            # Ensure required columns
            if 'text' not in df.columns:
                st.error("Dataset must have a 'text' column.")
                return
            
            if 'ground_truth' not in df. columns:
                df['ground_truth'] = ''
            
            st.session_state. dataset = df
            
        except Exception as e: 
            st.error(f"Failed to load file: {e}")
            return
    
    if st.session_state.dataset is not None:
        df = st.session_state. dataset
        
        st.subheader("📝 Annotate Ground Truth")
        st.caption("Edit the 'ground_truth' column to specify expected extractions.")
        
        # Configure AgGrid
        gb = GridOptionsBuilder.from_dataframe(df)
        gb.configure_default_column(
            resizable=True,
            filterable=True,
            sortable=True
        )
        gb.configure_column(
            "text",
            width=500,
            wrapText=True,
            autoHeight=True,
            editable=False
        )
        gb.configure_column(
            "ground_truth",
            editable=True,
            width=300,
            cellStyle={'backgroundColor': '#fffde7'}
        )
        gb.configure_selection(
            selection_mode='multiple',
            use_checkbox=True
        )
        gb.configure_pagination(paginationAutoPageSize=False, paginationPageSize=10)
        
        grid_response = AgGrid(
            df,
            gridOptions=gb.build(),
            update_mode=GridUpdateMode.VALUE_CHANGED,
            data_return_mode=DataReturnMode.FILTERED_AND_SORTED,
            fit_columns_on_grid_load=False,
            theme='streamlit',
            height=400
        )
        
        # Update session state with edited data
        st.session_state. dataset = pd.DataFrame(grid_response['data'])
        
        # Data statistics
        col1, col2, col3 = st.columns(3)
        annotated = (st.session_state. dataset['ground_truth'] != '').sum()
        total = len(st. session_state.dataset)
        train_size = int(total * st.session_state.train_test_split)
        
        with col1:
            st. metric("Total Samples", total)
        with col2:
            st.metric("Annotated", f"{annotated}/{total}")
        with col3:
            st.metric("Train/Val Split", f"{train_size}/{total - train_size}")
        
        # Sample data preview
        with st.expander("📋 Sample Preview"):
            st.dataframe(
                st.session_state.dataset.head(5),
                use_container_width=True
            )


def render_optimization_tab():
    """Render the optimization tab."""
    st.header("🧬 GEPA Optimization")
    
    if st.session_state. dataset is None:
        st.warning("⚠️ Please upload and annotate data first.")
        return
    
    df = st.session_state.dataset
    annotated_df = df[df['ground_truth'] != '']
    
    if len(annotated_df) < 2:
        st.warning("⚠️ Please annotate at least 2 samples.")
        return
    
    # Split configuration display
    split_idx = int(len(annotated_df) * st.session_state.train_test_split)
    train_df = annotated_df. iloc[:split_idx]
    val_df = annotated_df.iloc[split_idx:]
    
    col1, col2 = st.columns(2)
    with col1:
        st.info(f"📚 Training samples: {len(train_df)}")
    with col2:
        st.info(f"🧪 Validation samples: {len(val_df)}")
    
    # Optimization controls
    col1, col2, col3 = st.columns([1, 1, 2])
    
    with col1:
        run_button = st.button(
            "🚀 Run Optimization",
            type="primary",
            use_container_width=True
        )
    
    with col2:
        if st.button("🔄 Reset Results", use_container_width=True):
            st.session_state.optimized_program = None
            st.session_state.optimization_history = []
            st.rerun()
    
    if run_button:
        if not setup_dspy():
            return
        
        # Prepare training set
        trainset = [
            dspy.Example(
                raw_text=row['text'],
                ground_truth=row['ground_truth']
            ).with_inputs('raw_text')
            for _, row in train_df.iterrows()
        ]
        
        valset = [
            dspy.Example(
                raw_text=row['text'],
                ground_truth=row['ground_truth']
            ).with_inputs('raw_text')
            for _, row in val_df.iterrows()
        ]
        
        # Progress tracking
        progress_bar = st.progress(0)
        status_text = st. empty()
        
        try:
            with st.spinner("🧬 GEPA is evolving regex patterns..."):
                status_text.text("Initializing optimizer...")
                
                optimizer = GEPA(
                    metric=create_regex_metric(st.session_state.regex_flags),
                    num_iterations=st. session_state.gepa_config['num_iterations'],
                    num_candidates=st.session_state.gepa_config['num_candidates'],
                )
                
                progress_bar.progress(20)
                status_text.text("Creating initial program...")
                
                program = RegexGenerator(
                    doc=st.session_state.prompts['system_instruction'],
                    output_desc=st. session_state.prompts['output_description']
                )
                
                progress_bar.progress(40)
                status_text.text("Running optimization...")
                
                optimized = optimizer.compile(
                    program,
                    trainset=trainset,
                )
                
                progress_bar.progress(80)
                status_text.text("Evaluating on validation set...")
                
                # Evaluate on validation set
                metric_fn = create_regex_metric(st.session_state.regex_flags)
                val_scores = []
                for example in valset: 
                    pred = optimized(raw_text=example. raw_text)
                    result = metric_fn(example, pred)
                    val_scores.append(result. score)
                
                avg_score = sum(val_scores) / len(val_scores) if val_scores else 0
                
                progress_bar. progress(100)
                status_text.text("Complete!")
                
                st.session_state. optimized_program = optimized
                st.session_state.optimization_history.append({
                    'score': avg_score,
                    'prompt': optimized.predictor.signature.__doc__,
                    'timestamp': pd.Timestamp.now()
                })
                
                st. success(f"✅ Optimization Complete!  Validation Score: {avg_score:.2%}")
                
        except Exception as e: 
            st.error(f"Optimization failed: {e}")
            return
    
    # Display results
    if st. session_state.optimized_program: 
        st.subheader("📊 Results")
        
        with st.expander("🔍 Evolved Prompt", expanded=True):
            st.code(
                st.session_state.optimized_program.predictor. signature.__doc__,
                language="text"
            )
        
        # Optimization history
        if st.session_state.optimization_history:
            with st.expander("📈 Optimization History"):
                history_df = pd. DataFrame(st.session_state. optimization_history)
                st.dataframe(history_df, use_container_width=True)


def render_testing_tab():
    """Render the testing tab."""
    st.header("🔍 Test & Validate")
    
    if st.session_state.optimized_program is None:
        st. warning("⚠️ Please run optimization first.")
        return
    
    # Single test
    st.subheader("🧪 Single Test")
    
    test_input = st.text_area(
        "Enter test text",
        height=100,
        placeholder="Paste text here to extract regex pattern..."
    )
    
    col1, col2 = st.columns([1, 3])
    with col1:
        test_button = st.button("▶️ Generate & Run", type="primary")
    
    if test_button and test_input: 
        if not setup_dspy():
            return
        
        with st.spinner("Generating regex... "):
            try:
                result = st.session_state.optimized_program(raw_text=test_input)
                pattern = result.regex_pattern
                
                st.code(f"Generated Regex: {pattern}", language="regex")
                
                # Compile and test
                flags = 0
                for flag in st.session_state.regex_flags:
                    flags |= getattr(re, flag, 0)
                
                compiled = re.compile(pattern, flags)
                matches = compiled.findall(test_input)
                
                if matches:
                    st.success(f"✅ Found {len(matches)} match(es):")
                    for i, match in enumerate(matches, 1):
                        st.markdown(f"**Match {i}:** `{match}`")
                    
                    # Highlight matches in text
                    highlighted = test_input
                    for match in matches: 
                        highlighted = highlighted.replace(
                            match,
                            f"**: green[{match}]**"
                        )
                    st.markdown("**Highlighted text:**")
                    st.markdown(highlighted)
                else: 
                    st. warning("No matches found.")
                    
            except re.error as e:
                st.error(f"Invalid regex generated: {e}")
            except Exception as e: 
                st.error(f"Error:  {e}")
    
    st.divider()
    
    # Batch testing
    st. subheader("📋 Batch Testing")
    
    batch_file = st.file_uploader(
        "Upload test data (CSV with 'text' column)",
        type=["csv"],
        key="batch_test"
    )
    
    if batch_file:
        test_df = pd. read_csv(batch_file)
        
        if 'text' not in test_df. columns:
            st.error("CSV must have 'text' column.")
            return
        
        if st.button("🚀 Run Batch Test"):
            if not setup_dspy():
                return
            
            results = []
            progress = st.progress(0)
            
            for i, row in test_df.iterrows():
                try:
                    result = st.session_state.optimized_program(raw_text=row['text'])
                    pattern = result.regex_pattern
                    
                    flags = 0
                    for flag in st.session_state. regex_flags: 
                        flags |= getattr(re, flag, 0)
                    
                    match = re.search(pattern, row['text'], flags)
                    extracted = match.group(0) if match else ""
                    
                    results.append({
                        'text': row['text'][: 100] + '...' if len(row['text']) > 100 else row['text'],
                        'pattern': pattern,
                        'extracted': extracted,
                        'success': bool(match)
                    })
                except Exception as e:
                    results.append({
                        'text': row['text'][:100] + '...',
                        'pattern': 'ERROR',
                        'extracted': str(e),
                        'success': False
                    })
                
                progress. progress((i + 1) / len(test_df))
            
            results_df = pd. DataFrame(results)
            
            # Summary metrics
            success_rate = results_df['success']. mean()
            col1, col2 = st.columns(2)
            with col1:
                st.metric("Success Rate", f"{success_rate:.1%}")
            with col2:
                st.metric("Total Tests", len(results_df))
            
            # Results table
            st.dataframe(results_df, use_container_width=True)
            
            # Download results
            csv = results_df. to_csv(index=False)
            st.download_button(
                "📥 Download Results",
                csv,
                "batch_test_results. csv",
                "text/csv"
            )


# --- Main Application ---
def main():
    render_sidebar()
    
    st.title("🧬 GEPA Regex Optimizer")
    st.caption("Automated regex generation with DSPy and evolutionary optimization")
    
    tab1, tab2, tab3 = st.tabs([
        "📥 Data Ingestion",
        "🧬 Optimization",
        "🔍 Testing"
    ])
    
    with tab1:
        render_data_ingestion_tab()
    
    with tab2:
        render_optimization_tab()
    
    with tab3:
        render_testing_tab()
    
    # Footer
    st.divider()
    st.caption(
        "Built with Streamlit, DSPy, and GEPA | "
        "Configuration is auto-saved in the sidebar"
    )


if __name__ == "__main__": 
    main()