#!/usr/bin/env python3
import sys
import json
import logging
from pathlib import Path

logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

def validate_step(step, idx):
    required_keys = {
        "id": str,
        "name": str,
        "enabled": bool,
        "status": str,
        "exit_code": int,
        "duration_ms": int,
        "started_at": str,
        "ended_at": str,
        "command": str
    }
    
    for key, expected_type in required_keys.items():
        if key not in step:
            raise ValueError(f"Step[{idx}] missing required key: '{key}'")
        if not isinstance(step[key], expected_type):
            raise ValueError(f"Step[{idx}] '{key}' must be {expected_type.__name__}, got {type(step[key]).__name__}")

def validate_report(report_path: Path):
    if not report_path.exists():
        raise FileNotFoundError(f"Report file not found: {report_path}")

    try:
        report = json.loads(report_path.read_text(encoding="utf-8"))
    except json.JSONDecodeError as e:
        raise ValueError(f"Invalid JSON format: {e}")

    # Root Level
    if "schema_version" not in report or report["schema_version"] != "1.0":
        raise ValueError("Invalid or missing schema_version. Expected '1.0'")
    
    if "generated_at" not in report or not isinstance(report["generated_at"], str):
        raise ValueError("Missing or invalid 'generated_at' string")

    # Git
    if "git" not in report or not isinstance(report["git"], dict):
        raise ValueError("Missing or invalid 'git' object")
    if "sha" not in report["git"] or not isinstance(report["git"]["sha"], str):
        raise ValueError("Missing or invalid 'git.sha'")
    if "branch" not in report["git"] or not isinstance(report["git"]["branch"], str):
        raise ValueError("Missing or invalid 'git.branch'")

    # Overall
    if "overall" not in report or not isinstance(report["overall"], dict):
        raise ValueError("Missing or invalid 'overall' object")
    
    for key in ["duration_ms", "passed", "failed", "skipped", "total"]:
        if key not in report["overall"] or not isinstance(report["overall"][key], int):
            raise ValueError(f"Missing or invalid integer 'overall.{key}'")
    if "status" not in report["overall"] or not isinstance(report["overall"]["status"], str):
        raise ValueError("Missing or invalid string 'overall.status'")

    # Steps
    if "steps" not in report or not isinstance(report["steps"], list):
        raise ValueError("Missing or invalid 'steps' array")
    
    for idx, step in enumerate(report["steps"]):
        validate_step(step, idx)

    logging.info(f"Report {report_path} passed schema validation (v1.0).")

if __name__ == '__main__':
    if len(sys.argv) < 2:
        logging.error("Usage: validate_regression_report.py <path/to/report.json>")
        sys.exit(1)
        
    try:
        validate_report(Path(sys.argv[1]))
    except Exception as e:
        logging.error(f"Validation failed: {e}")
        sys.exit(1)