"""
Terraform AWS Knowledge Base (TF-KB)
=====================================
Build & query a knowledge base from the AWS Terraform provider schema.
Used for prompt preprocessing — maps NL prompts to exact resource types,
required arguments, and dependency chains.

Usage:
    from tf_knowledge_base import TerraformKB
    kb = TerraformKB()
    
    # Find resources mentioned in a prompt
    resources = kb.extract_resources("Create an S3 bucket with versioning")
    # → [{'resource_type': 'aws_s3_bucket', 'confidence': 0.9, ...}]
    
    # Get schema for a resource
    schema = kb.get_resource_schema('aws_s3_bucket')
    # → {'required': [...], 'optional': [...], 'nested_blocks': {...}}
    
    # Get dependencies
    deps = kb.get_dependencies('aws_route53_record')
    # → ['aws_route53_zone']
"""

import json
import os
import re
from pathlib import Path
from difflib import SequenceMatcher

KB_DIR = Path(__file__).parent / "tf_kb"
REGISTRY_PATH = KB_DIR / "resource_registry.json"
NL_MAPPING_PATH = KB_DIR / "nl_mapping.json"
DEP_GRAPH_PATH = KB_DIR / "dependency_graph.json"

# Load dependency graph from auto-generated JSON
# core_dependencies: always inject (IAM roles, parent resources)
# optional_dependencies: only inject when prompt mentions related features
def _load_dependency_map():
    if DEP_GRAPH_PATH.exists():
        with open(DEP_GRAPH_PATH) as f:
            data = json.load(f)
        # Prefer core_dependencies (filtered), fall back to full dependencies
        return data.get("core_dependencies", data.get("dependencies", {}))
    # Fallback to minimal hardcoded map if file missing
    return {
    "aws_route53_record": ["aws_route53_zone"],
    "aws_route53_zone_association": ["aws_route53_zone", "aws_vpc"],
    "aws_route53_vpc_association_authorization": ["aws_route53_zone", "aws_vpc"],
    "aws_route53_query_log": ["aws_route53_zone", "aws_cloudwatch_log_group"],
    "aws_subnet": ["aws_vpc"],
    "aws_security_group": ["aws_vpc"],
    "aws_security_group_rule": ["aws_security_group"],
    "aws_internet_gateway": ["aws_vpc"],
    "aws_nat_gateway": ["aws_subnet", "aws_eip"],
    "aws_route_table": ["aws_vpc"],
    "aws_route_table_association": ["aws_route_table", "aws_subnet"],
    "aws_route": ["aws_route_table"],
    "aws_network_acl": ["aws_vpc"],
    "aws_instance": ["aws_subnet", "aws_security_group"],
    "aws_lb": ["aws_subnet", "aws_security_group"],
    "aws_lb_target_group": ["aws_vpc"],
    "aws_lb_listener": ["aws_lb"],
    "aws_lb_listener_rule": ["aws_lb_listener"],
    "aws_db_instance": ["aws_db_subnet_group"],
    "aws_db_subnet_group": ["aws_subnet"],
    "aws_elasticache_cluster": ["aws_elasticache_subnet_group"],
    "aws_elasticache_subnet_group": ["aws_subnet"],
    "aws_elastic_beanstalk_environment": ["aws_elastic_beanstalk_application", "aws_iam_instance_profile"],
    "aws_elastic_beanstalk_application_version": ["aws_elastic_beanstalk_application", "aws_s3_bucket", "aws_s3_object"],
    "aws_iam_instance_profile": ["aws_iam_role"],
    "aws_iam_role_policy_attachment": ["aws_iam_role", "aws_iam_policy"],
    "aws_iam_role_policy": ["aws_iam_role"],
    "aws_iam_policy_document": [],
    "aws_lambda_function": ["aws_iam_role"],
    "aws_lambda_permission": ["aws_lambda_function"],
    "aws_lambda_event_source_mapping": ["aws_lambda_function"],
    "aws_ecs_service": ["aws_ecs_cluster", "aws_ecs_task_definition"],
    "aws_ecs_task_definition": ["aws_iam_role"],
    "aws_eks_node_group": ["aws_eks_cluster", "aws_subnet", "aws_iam_role"],
    "aws_s3_bucket_versioning": ["aws_s3_bucket"],
    "aws_s3_bucket_server_side_encryption_configuration": ["aws_s3_bucket"],
    "aws_s3_bucket_lifecycle_configuration": ["aws_s3_bucket"],
    "aws_s3_bucket_logging": ["aws_s3_bucket"],
    "aws_s3_bucket_policy": ["aws_s3_bucket"],
    "aws_s3_bucket_public_access_block": ["aws_s3_bucket"],
    "aws_s3_bucket_acl": ["aws_s3_bucket"],
    "aws_s3_bucket_cors_configuration": ["aws_s3_bucket"],
    "aws_s3_bucket_website_configuration": ["aws_s3_bucket"],
    "aws_s3_bucket_notification": ["aws_s3_bucket"],
    "aws_s3_object": ["aws_s3_bucket"],
    "aws_cloudwatch_log_resource_policy": ["aws_cloudwatch_log_group"],
    "aws_cloudwatch_metric_alarm": [],
    "aws_cloudfront_distribution": [],
    "aws_acm_certificate_validation": ["aws_acm_certificate", "aws_route53_record"],
    "aws_autoscaling_group": ["aws_launch_template"],
    "aws_launch_template": ["aws_security_group"],
    "aws_codebuild_project": ["aws_iam_role"],
    "aws_codepipeline": ["aws_iam_role", "aws_s3_bucket"],
    "aws_sfn_state_machine": ["aws_iam_role"],
    "aws_api_gateway_rest_api": [],
    "aws_api_gateway_resource": ["aws_api_gateway_rest_api"],
    "aws_api_gateway_method": ["aws_api_gateway_rest_api", "aws_api_gateway_resource"],
    "aws_kms_alias": ["aws_kms_key"],
    }

DEPENDENCY_MAP = _load_dependency_map()


class TerraformKB:
    def __init__(self):
        with open(REGISTRY_PATH) as f:
            data = json.load(f)
        self.resources = data["resources"]
        self.data_sources = data["data_sources"]
        self.resource_types = set(self.resources.keys())
        
        with open(NL_MAPPING_PATH) as f:
            self.nl_mapping = json.load(f)
    
    def get_resource_schema(self, resource_type: str) -> dict | None:
        """Get full schema for a resource type."""
        return self.resources.get(resource_type)
    
    def get_required_args(self, resource_type: str) -> list[str]:
        """Get required argument names for a resource."""
        schema = self.resources.get(resource_type, {})
        args = [a["name"] for a in schema.get("required", [])]
        # Also check nested blocks with min_items > 0
        for bname, binfo in schema.get("nested_blocks", {}).items():
            if binfo.get("min_items", 0) > 0:
                args.append(f"{bname} {{...}}")
        return args
    
    def get_optional_args(self, resource_type: str) -> list[str]:
        """Get optional argument names for a resource."""
        schema = self.resources.get(resource_type, {})
        return [a["name"] for a in schema.get("optional", [])]
    
    def get_nested_blocks(self, resource_type: str) -> list[str]:
        """Get nested block names for a resource."""
        schema = self.resources.get(resource_type, {})
        return list(schema.get("nested_blocks", {}).keys())
    
    def get_dependencies(self, resource_type: str) -> list[str]:
        """Get common dependencies for a resource type."""
        return DEPENDENCY_MAP.get(resource_type, [])
    
    def resource_exists(self, resource_type: str) -> bool:
        """Check if a resource type exists in the AWS provider."""
        return resource_type in self.resource_types
    
    def find_similar_resources(self, name: str, top_k: int = 5) -> list[tuple[str, float]]:
        """Find similar resource types by fuzzy matching."""
        scores = []
        for rtype in self.resource_types:
            score = SequenceMatcher(None, name.lower(), rtype.lower()).ratio()
            scores.append((rtype, score))
        scores.sort(key=lambda x: x[1], reverse=True)
        return scores[:top_k]
    
    def extract_resources(self, prompt: str) -> list[dict]:
        """
        Extract likely AWS resource types from a natural language prompt.
        Returns list of {'resource_type': str, 'confidence': float, 'matched_text': str}
        """
        prompt_lower = prompt.lower()
        candidates = {}  # resource_type → best match info
        
        # Strategy 1: Direct resource type mention (aws_xxx_yyy)
        direct_matches = re.findall(r'aws_[a-z_]+', prompt_lower)
        for match in direct_matches:
            if match in self.resource_types:
                candidates[match] = {'confidence': 1.0, 'matched_text': match, 'strategy': 'direct'}
        
        # Strategy 2: NL keyword matching
        # Check bigrams first (more specific), then unigrams
        words = re.findall(r'[a-z][a-z0-9]+', prompt_lower)
        
        # Bigrams — prefer exact base resource over sub-resources
        for i in range(len(words) - 1):
            bigram = f"{words[i]}_{words[i+1]}"
            if bigram in self.nl_mapping:
                matched = self.nl_mapping[bigram]
                # Prefer the shortest/base resource (e.g., aws_s3_bucket over aws_s3_bucket_acl)
                base_resource = f"aws_{bigram}"
                for rtype in matched:
                    if rtype == base_resource:
                        # Exact base match gets high confidence
                        candidates[rtype] = {
                            'confidence': 0.9,
                            'matched_text': f"{words[i]} {words[i+1]}",
                            'strategy': 'bigram_exact'
                        }
                    elif rtype not in candidates:
                        # Sub-resources get lower confidence — only added if
                        # prompt specifically mentions them
                        candidates[rtype] = {
                            'confidence': 0.3,
                            'matched_text': f"{words[i]} {words[i+1]}",
                            'strategy': 'bigram_sub'
                        }
            # Also check as single key (e.g., "security group", "load balancer")
            phrase = f"{words[i]} {words[i+1]}"
            if phrase in self.nl_mapping:
                for rtype in self.nl_mapping[phrase]:
                    if rtype not in candidates or candidates[rtype]['confidence'] < 0.85:
                        candidates[rtype] = {
                            'confidence': 0.85,
                            'matched_text': phrase,
                            'strategy': 'phrase'
                        }
        
        # Unigrams (lower confidence, skip common English words)
        STOPWORDS = {'create', 'set', 'up', 'add', 'with', 'and', 'the', 'for',
                     'this', 'that', 'from', 'into', 'use', 'using', 'make',
                     'has', 'have', 'get', 'put', 'new', 'two', 'three', 'one',
                     'all', 'each', 'any', 'both', 'should', 'must', 'will',
                     'can', 'may', 'also', 'deploy', 'provision', 'configure',
                     'enable', 'enabled', 'disable', 'disabled', 'include',
                     'including', 'specify', 'specified', 'ensure', 'allow',
                     'name', 'named', 'type', 'value', 'key', 'default',
                     'index', 'global', 'local', 'primary', 'secondary',
                     'public', 'private', 'internal', 'external'}
        for word in words:
            # Try exact match, then singular form (strip trailing 's'/'es')
            lookup_words = [word]
            if word.endswith('ies'):
                lookup_words.append(word[:-3] + 'y')  # policies → policy
            elif word.endswith('ses') or word.endswith('xes') or word.endswith('zes'):
                lookup_words.append(word[:-2])  # instances → instance
            elif word.endswith('s') and not word.endswith('ss'):
                lookup_words.append(word[:-1])  # subnets → subnet
            
            for lw in lookup_words:
                if lw in self.nl_mapping and len(lw) > 2 and lw not in STOPWORDS:
                    for rtype in self.nl_mapping[lw]:
                        if rtype not in candidates:
                            candidates[rtype] = {
                                'confidence': 0.5,
                                'matched_text': word,
                                'strategy': 'unigram'
                            }
                    break  # found match, don't try other forms
        
        # Strategy 3: Common service name patterns
        service_patterns = {
            r'\bs3\b': ['aws_s3_bucket'],
            r'\bec2\b': ['aws_instance'],
            r'\brds\b': ['aws_db_instance'],
            r'\bvpc\b': ['aws_vpc'],
            r'\blambda\b': ['aws_lambda_function'],
            r'\bdynamodb\b': ['aws_dynamodb_table'],
            r'\bsqs\b': ['aws_sqs_queue'],
            r'\bsns\b': ['aws_sns_topic'],
            r'\becs\b': ['aws_ecs_cluster'],
            r'\beks\b': ['aws_eks_cluster'],
            r'\becr\b': ['aws_ecr_repository'],
            r'\bkms\b': ['aws_kms_key'],
            r'\bacm\b': ['aws_acm_certificate'],
            r'\biam\b': ['aws_iam_role'],
            r'\bwaf\b': ['aws_wafv2_web_acl'],
            r'\bssm\b': ['aws_ssm_parameter'],
            r'\bsubnets?\b': ['aws_subnet'],
            r'\bsecurity.?groups?\b': ['aws_security_group'],
            r'\bnat.?gateways?\b': ['aws_nat_gateway'],
            r'\binternet.?gateways?\b': ['aws_internet_gateway'],
            r'\broute.?tables?\b': ['aws_route_table'],
            r'\belastic.?beanstalk\b': ['aws_elastic_beanstalk_application', 'aws_elastic_beanstalk_environment'],
            r'\bcloud.?front\b': ['aws_cloudfront_distribution'],
            r'\bauto.?scaling\b': ['aws_autoscaling_group'],
            r'\belastic.?cache\b': ['aws_elasticache_cluster'],
            r'\bredshift\b': ['aws_redshift_cluster'],
            r'\bcloud.?watch\b': ['aws_cloudwatch_metric_alarm'],
            r'\bcode.?pipeline\b': ['aws_codepipeline'],
            r'\bcode.?build\b': ['aws_codebuild_project'],
            r'\bstep.?functions?\b': ['aws_sfn_state_machine'],
            r'\bapi.?gateway\b': ['aws_api_gateway_rest_api'],
            r'\bfargate\b': ['aws_ecs_cluster', 'aws_ecs_service', 'aws_ecs_task_definition'],
            r'\balb\b|\bapplication.?load.?balancer\b': ['aws_lb', 'aws_lb_target_group', 'aws_lb_listener'],
            r'\bnlb\b|\bnetwork.?load.?balancer\b': ['aws_lb'],
            r'\broute.?53\b': ['aws_route53_zone'],
        }
        for pattern, rtypes in service_patterns.items():
            if re.search(pattern, prompt_lower):
                for rtype in rtypes:
                    if rtype not in candidates or candidates[rtype]['confidence'] < 0.7:
                        candidates[rtype] = {
                            'confidence': 0.7,
                            'matched_text': re.search(pattern, prompt_lower).group(),
                            'strategy': 'service_pattern'
                        }
        
        # Build result list sorted by confidence
        results = []
        for rtype, info in candidates.items():
            results.append({
                'resource_type': rtype,
                'confidence': info['confidence'],
                'matched_text': info['matched_text'],
                'strategy': info['strategy']
            })
        results.sort(key=lambda x: x['confidence'], reverse=True)
        # Filter: only return high-confidence matches by default
        # Keep sub-resources only if their base is also matched
        base_types = {r['resource_type'] for r in results if r['confidence'] >= 0.7}
        filtered = []
        for r in results:
            if r['confidence'] >= 0.5:
                filtered.append(r)
            elif r['strategy'] == 'bigram_sub':
                # Keep sub-resource only if base resource is in scope
                # e.g., keep aws_s3_bucket_versioning if aws_s3_bucket matched
                base = '_'.join(r['resource_type'].split('_')[:3])  # aws_s3_bucket
                if base in base_types:
                    continue  # skip sub-resources, they'll be suggested via nested_blocks
        return filtered
    
    def get_resource_summary(self, resource_type: str) -> str:
        """Get a concise text summary of a resource for prompt injection."""
        if resource_type not in self.resources:
            similar = self.find_similar_resources(resource_type, top_k=3)
            return f"WARNING: '{resource_type}' does not exist. Did you mean: {', '.join(s[0] for s in similar)}?"
        
        schema = self.resources[resource_type]
        required = [a["name"] for a in schema.get("required", [])]
        nested = list(schema.get("nested_blocks", {}).keys())
        # Filter out 'timeouts' from nested — it's always there and not useful
        nested = [n for n in nested if n != "timeouts"]
        
        deps = self.get_dependencies(resource_type)
        
        lines = [f"  {resource_type}:"]
        if required:
            lines.append(f"    Required args: {', '.join(required)}")
        if nested:
            lines.append(f"    Nested blocks: {', '.join(nested)}")
        if deps:
            lines.append(f"    Typically needs: {', '.join(deps)}")
        
        return "\n".join(lines)
    
    def build_enrichment(self, resource_types: list[str]) -> str:
        """
        Build enrichment text for a list of resource types.
        Includes schemas + auto-resolved dependencies.
        """
        all_resources = set(resource_types)
        # Auto-resolve dependencies
        to_check = list(resource_types)
        while to_check:
            rt = to_check.pop()
            for dep in self.get_dependencies(rt):
                if dep not in all_resources:
                    all_resources.add(dep)
                    to_check.append(dep)
        
        lines = ["Resources and their schemas:"]
        for rt in sorted(all_resources):
            lines.append(self.get_resource_summary(rt))
        
        # Add dependency info
        dep_lines = []
        for rt in sorted(all_resources):
            deps = self.get_dependencies(rt)
            deps_in_scope = [d for d in deps if d in all_resources]
            if deps_in_scope:
                dep_lines.append(f"  {rt} → depends on: {', '.join(deps_in_scope)}")
        
        if dep_lines:
            lines.append("\nDependency chain:")
            lines.extend(dep_lines)
        
        return "\n".join(lines)


def build_kb():
    """Rebuild the knowledge base from terraform provider schema."""
    import subprocess
    
    tmpdir = "/tmp/tf-schema"
    os.makedirs(tmpdir, exist_ok=True)
    
    main_tf = os.path.join(tmpdir, "main.tf")
    with open(main_tf, "w") as f:
        f.write('''terraform {
  required_providers {
    aws = { source = "hashicorp/aws", version = "~> 5.0" }
  }
}
provider "aws" {
  region                      = "us-east-1"
  skip_credentials_validation = true
  skip_metadata_api_check     = true
  skip_requesting_account_id  = true
  access_key                  = "mock"
  secret_key                  = "mock"
}
''')
    
    print("Running terraform init...")
    subprocess.run(["terraform", "init", "-input=false"], cwd=tmpdir, capture_output=True)
    
    print("Extracting provider schema...")
    result = subprocess.run(
        ["terraform", "providers", "schema", "-json"],
        cwd=tmpdir, capture_output=True, text=True
    )
    schema = json.loads(result.stdout)
    
    # Parse and save (same logic as build script)
    provider_key = [k for k in schema['provider_schemas'] if 'aws' in k][0]
    ps = schema['provider_schemas'][provider_key]
    # ... (parsing logic)
    print(f"Schema extracted from {provider_key}")


# Quick test
if __name__ == "__main__":
    kb = TerraformKB()
    
    print(f"=== TF-KB Stats ===")
    print(f"Resources: {len(kb.resources)}")
    print(f"Data sources: {len(kb.data_sources)}")
    print()
    
    # Test extract
    test_prompts = [
        "Create an S3 bucket with versioning enabled",
        "Set up a VPC with two subnets and an internet gateway",
        "Create a Route53 zone and add a DNS record",
        "Deploy an Elastic Beanstalk application with an IAM role",
        "Create a DynamoDB table with a global secondary index",
    ]
    
    for prompt in test_prompts:
        print(f"Prompt: {prompt}")
        resources = kb.extract_resources(prompt)
        for r in resources[:5]:
            print(f"  → {r['resource_type']} (conf={r['confidence']:.1f}, via {r['strategy']}: '{r['matched_text']}')")
        
        # Show enrichment for top resources
        top_types = [r['resource_type'] for r in resources[:3]]
        if top_types:
            enrichment = kb.build_enrichment(top_types)
            print(f"\n  Enrichment:\n{enrichment}")
        print()