#!/usr/bin/env python3
from __future__ import annotations

import hashlib
import sys
from datetime import datetime, timezone, timedelta
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent

# Define source-to-bundle mapping
BUNDLES = {
    "gas_lib.gs": [
        "src/gas/core/gas_lib.gs"
    ],
    "gas_data_collect.gs": [
        "src/gas_adapter_parts/gdc_01_fetch_fundamentals.gs",
        "src/gas_adapter_parts/gdc_02_account_satellite.gs"
    ],
    "gas_data_feed.gs": [
        "src/gas_adapter_parts/gdf_01_price_metrics.gs",
        "src/gas_adapter_parts/gdf_02_harness_assembly.gs",
        "src/gas_adapter_parts/gdf_03_portfolio_gates.gs",
        "src/gas_adapter_parts/gdf_04_execution_quality.gs",
        "src/gas_adapter_parts/gdf_05_alpha_engines.gs",
        "src/gas_adapter_parts/gdf_06_rebalance.gs"
    ]
}

def get_now_kst() -> str:
    kst = timezone(timedelta(hours=9))
    return datetime.now(kst).strftime("%Y-%m-%d %H:%M:%S KST")

def compute_hash(contents: str) -> str:
    return hashlib.sha256(contents.encode("utf-8")).hexdigest()

def build_bundles() -> int:
    now_str = get_now_kst()
    print(f"[build_gas_bundle] Started bundling at {now_str}")
    
    for bundle_name, src_relative_paths in BUNDLES.items():
        dst_path = ROOT / bundle_name
        
        # Concatenate source file contents
        concatenated_lines = []
        for src_rel in src_relative_paths:
            src_path = ROOT / src_rel
            if not src_path.exists():
                print(f"ERROR: Source file not found: {src_rel}")
                return 1
            
            content = src_path.read_text(encoding="utf-8")
            concatenated_lines.append(f"// --- Source: {src_rel} ---")
            concatenated_lines.append(content)
            concatenated_lines.append("")
            
        full_source_content = "\n".join(concatenated_lines)
        source_hash = compute_hash(full_source_content)
        
        # Build the bundled file content with the generated header
        bundle_content = f"""// =========================================================================
// GENERATED BUNDLE - DO NOT EDIT THIS FILE MANUALLY
// Generated At: {now_str}
// Source Files: {", ".join(src_relative_paths)}
// Source Hash: {source_hash}
// =========================================================================

{full_source_content}"""
        
        # Write to destination
        dst_path.write_text(bundle_content, encoding="utf-8")
        print(f"  [build_gas_bundle] Generated bundle: {bundle_name} (Hash: {source_hash[:8]})")
        
    print("[build_gas_bundle] All bundles generated successfully.")
    return 0

if __name__ == "__main__":
    sys.exit(build_bundles())