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"""
Report generation for agent security scanning.

This module converts LLM-generated vulnerability XML into the standardized 
frontend report format (schema: agent-security-report@1).
"""

import re
import time
from typing import Any, Dict, List, Optional
from collections import defaultdict

from .models import (
    Severity,
    AgentSecurityReport,
    VulnerabilityFinding,
    OWASPASISummary,
    ConversationTurn,
)


# OWASP ASI category definitions
ASI_CATEGORIES = {
    "ASI01": "Agent Goal Hijack",
    "ASI02": "Tool Misuse & Exploitation",
    "ASI03": "Identity & Privilege Abuse",
    "ASI04": "Agentic Supply Chain Vulnerabilities",
    "ASI05": "Unexpected Code Execution",
    "ASI06": "Memory & Context Poisoning",
    "ASI07": "Insecure Inter-Agent Communication",
    "ASI08": "Cascading Failures",
    "ASI09": "Human-Agent Trust Exploitation",
    "ASI10": "Rogue Agents",
}


def _severity_to_level(severity: Severity) -> str:
    """Convert Severity enum to frontend level string."""
    mapping = {
        Severity.HIGH: "High",
        Severity.MEDIUM: "Medium",
        Severity.LOW: "Low",
    }
    return mapping.get(severity, "Low")


def _extract_tag_content(text: str, tag: str) -> Optional[str]:
    """Extract content from XML-like tag."""
    pattern = re.compile(rf'<{tag}>\s*(.*?)\s*</{tag}>', re.DOTALL)
    match = pattern.search(text)
    return match.group(1).strip() if match else None


def _extract_conversation_from_xml(block: str) -> List[Dict[str, Optional[str]]]:
    """
    Extract conversation from <conversation> XML tag.
    
    Supports format:
    <conversation>
      <turn>
        <prompt>...</prompt>
        <response>...</response>
      </turn>
    </conversation>
    """
    conversation = []
    conversation_tag = _extract_tag_content(block, 'conversation')
    
    if conversation_tag:
        turn_pattern = re.compile(r'<turn>\s*(.*?)\s*</turn>', re.DOTALL)
        turns = turn_pattern.findall(conversation_tag)
        
        for turn_block in turns:
            prompt = _extract_tag_content(turn_block, 'prompt')
            response = _extract_tag_content(turn_block, 'response')
            if prompt or response:
                conversation.append({
                    'prompt': prompt,
                    'response': response
                })
    
    return conversation


def _is_example_placeholder(text: str) -> bool:
    """
    Check if text contains example/placeholder data that should be filtered out.
    
    Filters obvious placeholder patterns like example API keys and test data.
    """
    if not text:
        return False
    
    text_lower = text.lower()

    example_key_patterns = [
        r'sk-abc123def456',
        r'sk-proj-(?:abc|test|demo|example|sample)\d{3,4}',
    ]
    for pattern in example_key_patterns:
        if re.search(pattern, text_lower):
            return True

    placeholder_patterns = [
        r'\[user\]', r'<password>', r'\{variable\}',
        r'\[your[_-]?api[_-]?key\]',
        r'\[.*?api[_-]?key.*?\]',
    ]
    
    if any(re.search(p, text_lower) for p in placeholder_patterns):
        if '```' not in text and '`' not in text:
            return True

    if any(word in text_lower for word in ['example api key', 'test key', 'dummy key', 'placeholder key']):
        return True
    
    return False


def _extract_vuln_blocks(text: str) -> List[Dict[str, Any]]:
    """Extract vulnerability blocks from XML-formatted text."""
    pattern = re.compile(r'<vuln>\s*(.*?)\s*</vuln>', re.DOTALL)
    vuln_blocks = pattern.findall(text)
    
    vulnerabilities = []
    for block in vuln_blocks:
        title = _extract_tag_content(block, 'title')
        desc = _extract_tag_content(block, 'desc')
        risk_type = _extract_tag_content(block, 'risk_type')
        level = _extract_tag_content(block, 'level')
        suggestion = _extract_tag_content(block, 'suggestion')
        
        conversation = _extract_conversation_from_xml(block)

        combined_text = f"{desc or ''} {title or ''}"
        if conversation:
            for turn in conversation:
                combined_text += f" {turn.get('prompt', '')} {turn.get('response', '')}"
        
        if _is_example_placeholder(combined_text):
            continue
        
        if title and desc and risk_type:
            vulnerabilities.append({
                'title': title,
                'description': desc,
                'risk_type': risk_type,
                'level': level or 'Medium',
                'suggestion': suggestion or '',
                'conversation': conversation,
            })
    
    return vulnerabilities


def _level_to_severity(level: str) -> Severity:
    """Convert level string to Severity enum. Unknown/info treated as Low."""
    level_lower = level.lower()
    if level_lower in ['critical', 'high']:
        return Severity.HIGH
    elif level_lower == 'medium':
        return Severity.MEDIUM
    elif level_lower == 'low':
        return Severity.LOW
    return Severity.LOW


def _extract_asi_from_risk_type(risk_type: str) -> str:
    """Extract ASI category from risk_type. Expects format 'ASI0X: Category Name' (per agent_security_reviewer)."""
    asi_match = re.search(r'asi0?(\d+)', risk_type, re.IGNORECASE)
    if asi_match:
        return f"ASI{asi_match.group(1).zfill(2)}"
    return 'ASI10'  # Unclassified


def calculate_security_score(vulnerabilities: List[Dict[str, str]]) -> int:
    """
    Calculate security score (0-100) from vulnerability list.
    
    Scoring:
    - HIGH/Critical: -15 per finding
    - MEDIUM: -8 per finding
    - LOW: -3 per finding
    """
    if not vulnerabilities:
        return 100
    
    penalty = 0
    for vuln in vulnerabilities:
        level = vuln.get('level', '').lower()
        if level in ['critical', 'high']:
            penalty += 15
        elif level == 'medium':
            penalty += 8
        elif level == 'low':
            penalty += 3
    
    return max(0, 100 - penalty)


def generate_report_from_xml(
    vuln_text: str,
    agent_name: str = "",
    agent_type: str = "",
    model_name: str = "",
    plugins: Optional[List[str]] = None,
    start_time: Optional[int] = None,
    end_time: Optional[int] = None,
    total_tests: int = 0,
    report_description: str = "",
) -> AgentSecurityReport:
    """
    Generate security report from XML-formatted vulnerability text.
    
    This function is used by the agent pipeline to convert LLM-generated
    vulnerability reports into the standardized frontend format.
    
    Args:
        vuln_text: XML-formatted text containing <vuln> blocks
        agent_name: Name of the scanned agent
        agent_type: Type of agent (e.g., "dify", "langchain")
        model_name: Evaluation model name (e.g., "openai/gpt-4")
        plugins: List of detection plugins/strategies used
        start_time: Scan start timestamp (defaults to current time)
        end_time: Scan end timestamp (defaults to current time)
        total_tests: Total number of tests executed
        report_description: Markdown description of the scan
        
    Returns:
        AgentSecurityReport ready for frontend consumption
    """
    vuln_list = _extract_vuln_blocks(vuln_text)

    # Use passed total_tests, default to vuln_list length if 0
    if total_tests == 0 and len(vuln_list) > 0:
         total_tests = len(vuln_list)

    now = int(time.time())
    start_time = start_time or now
    end_time = end_time or now

    findings: List[VulnerabilityFinding] = []
    asi_findings: Dict[str, List[str]] = defaultdict(list)
    asi_severity: Dict[str, List[Severity]] = defaultdict(list)
    
    for i, vuln in enumerate(vuln_list, 1):
        finding_id = f"f-{i:03d}"
        severity = _level_to_severity(vuln['level'])
        asi_category = _extract_asi_from_risk_type(vuln['risk_type'])

        conversation = [
            ConversationTurn(prompt=turn.get('prompt'), response=turn.get('response'))
            for turn in vuln.get('conversation', [])
        ]
        
        finding = VulnerabilityFinding(
            id=finding_id,
            type=vuln['risk_type'].lower().replace(' ', '_'),
            title=vuln['title'],
            description=vuln['description'],
            level=_severity_to_level(severity),
            owasp=[asi_category],
            suggestion=vuln['suggestion'],
            conversation=conversation,
        )
        findings.append(finding)
        
        asi_findings[asi_category].append(finding_id)
        asi_severity[asi_category].append(severity)

    owasp_summary: List[OWASPASISummary] = []
    severity_rank = {Severity.HIGH: 3, Severity.MEDIUM: 2, Severity.LOW: 1}
    
    for asi_id, finding_ids in asi_findings.items():
        severities = asi_severity[asi_id]
        if not severities:
            continue
        high_or_above = sum(1 for s in severities if s == Severity.HIGH)
        max_severity = max(severities, key=lambda s: severity_rank.get(s, 0))
        
        owasp_summary.append(OWASPASISummary(
            id=asi_id,
            name=ASI_CATEGORIES.get(asi_id, "Unknown"),
            total=len(finding_ids),
            high_or_above=high_or_above,
            max_level=max_severity.value,
            findings=finding_ids,
        ))
    
    owasp_summary.sort(key=lambda x: -severity_rank.get(Severity(x.max_level), 0))

    score = calculate_security_score(vuln_list)
    
    # Determine overall risk type based on vulnerabilities found
    if not vuln_list:
        # No vulnerabilities found - report as safe
        risk_type = "safe"
    elif any(v['level'].lower() in ['critical', 'high'] for v in vuln_list):
        risk_type = "high"
    elif any(v['level'].lower() == 'medium' for v in vuln_list):
        risk_type = "medium"
    else:
        risk_type = "low"

    if not report_description:
        desc_parts = [
            f"## Agent Security Scan Report\n",
            f"Scanned agent with **{len(vuln_list)}** vulnerabilities found.\n",
        ]
        if vuln_list:
            desc_parts.append("\n### Findings by Severity\n")
            severity_counts = defaultdict(int)
            for v in vuln_list:
                level = v['level'].upper()
                if level in ['CRITICAL', 'HIGH']:
                    severity_counts['HIGH'] += 1
                elif level == 'MEDIUM':
                    severity_counts['MEDIUM'] += 1
                else:
                    severity_counts['LOW'] += 1
            for sev in ['HIGH', 'MEDIUM', 'LOW']:
                if severity_counts[sev] > 0:
                    desc_parts.append(f"- **{sev}**: {severity_counts[sev]}\n")
        report_description = "".join(desc_parts)
    
    return AgentSecurityReport(
        schema_version="agent-security-report@1",
        agent_name=agent_name,
        agent_type=agent_type,
        # model_name=model_name,
        start_time=start_time,
        end_time=end_time,
        plugins=plugins or [],
        score=score,
        risk_type=risk_type,
        total_tests=total_tests if total_tests > 0 else len(vuln_list),
        vulnerable_tests=len(vuln_list),
        results=findings,
        owasp_agentic_2026_top10=owasp_summary,
        report_description=report_description,
    )