import json
import graphviz
import trino
import os
import sys
import logging
import concurrent.futures
from concurrent.futures import ThreadPoolExecutor
from cachier import cachier
import datetime

logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
logger = logging.getLogger("trino")
logger.setLevel(logging.DEBUG)

def create_trino_connection():
    return trino.dbapi.connect(
        host=os.getenv("STARBURST_HOST"),
        port=443,
        http_scheme="https",
        verify=True,
        user=os.getenv("STARBURST_DEV_USER"),
        auth=trino.auth.OAuth2Authentication(),
    )

def read_manifest(file_path):
    with open(file_path, 'r') as f:
        return json.load(f)


def build_graphviz_graph(manifest, previous_stages_dict):

    dot = graphviz.Digraph(comment='DBT Models')
    dot.graph_attr['rankdir'] = 'LR'
    threshold = 10.0  # Set your threshold value

    if os.path.exists('results.tsv'):
        os.remove('results.tsv')

    with open('results.tsv', 'w') as f:
        f.write('node_name\tstages\n')

        with ThreadPoolExecutor(max_workers=4) as executor:
            futures = {executor.submit(get_query_stages, node_name, node_data['compiled_code']): node_name for node_name, node_data in manifest['nodes'].items() if node_data['compiled_code'] and not node_name.startswith('test.')}

            for future in futures:
                node_name, stages = future.result()
                f.write(f"{node_name}\t{stages}\n")

                # Check for high relative increase in stages
                dependencies = manifest['nodes'][node_name].get('depends_on', {}).get('nodes', [])
                input_stages = [previous_stages_dict.get(dep, 0) for dep in dependencies]

                if input_stages:
                    avg_input_stages = sum(input_stages) / len(input_stages)
                    if avg_input_stages > 0 and stages / avg_input_stages >= threshold:  # Check for non-zero
                        dot.node(node_name, f"{node_name.split('.')[-1]}\n{stages} stages", style="filled", fillcolor="red")
                    else:
                        dot.node(node_name, f"{node_name.split('.')[-1]}\n{stages} stages")
                else:
                    dot.node(node_name, f"{node_name.split('.')[-1]}\n{stages} stages")

                for dep in dependencies:
                    dot.edge(dep, node_name)

                previous_stages_dict[node_name] = stages

    return dot

@cachier(stale_after=datetime.timedelta(minutes=60))
def get_plan(node_name, sql):
    # remove ; from any part of the statement
    sql = sql.replace(';', '')
    cur = create_trino_connection().cursor()
    cur.execute(f"EXPLAIN (TYPE DISTRIBUTED, FORMAT JSON) {sql}")
    row = cur.fetchone()
    explain_json = json.loads(row[0])
    cur.close()
    return explain_json


def get_query_stages(node_name, sql):
    stages = count_stages_in_query_plan(get_plan(node_name, sql))
    return node_name, stages

def is_virtual_stage(stage):
    # Check for 'estimates' key in the stage
    estimates_list = stage.get('estimates', [])

    for estimates in estimates_list:
        # Check for 'NaN' or 0.0 in relevant fields
        if not (
            estimates.get('outputSizeInBytes', 'NaN') == 'NaN' and
            estimates.get('cpuCost', 'NaN') == 'NaN' and
            estimates.get('memoryCost', 0.0) == 0.0 and
            estimates.get('networkCost', 0.0) == 0.0
        ):
            return False
    return True

def count_stages_in_query_plan(query_plan):
    stage_count = 0

    if isinstance(query_plan, dict):
        # If this stage is "virtual" (has no cost), do not count it
        if not is_virtual_stage(query_plan):
            stage_count += 1

        for key, value in query_plan.items():
            if isinstance(value, dict):
                # Count this as a stage and explore its children
                stage_count += count_stages_in_query_plan(value)
            elif isinstance(value, list):
                for item in value:
                    if isinstance(item, dict):
                        stage_count += count_stages_in_query_plan(item)
            else:
                print(f"Warning: Unexpected non-dict value encountered for stage {key}: {value}")

    return stage_count

if __name__ == "__main__":
    manifest_file_path = "./target/manifest.json"
    manifest = read_manifest(manifest_file_path)
    previous_stages_dict = {}
    dot = build_graphviz_graph(manifest, previous_stages_dict)
    # save dotfile to disk
    dot.save('output.dot')
    dot.render('output', view=True, format='png')