import json
import sqlite3
import time
from typing import List, Optional

from .workflow_definition import Workflow


class WorkflowStorage:
    def __init__(self, db_path: str):
        self.db_path = db_path
        self._initialize_storage()

    def _initialize_storage(self):
        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        cursor.execute(
            """
            CREATE TABLE IF NOT EXISTS workflows (
                workflow_id TEXT PRIMARY KEY,
                name TEXT NOT NULL,
                description TEXT,
                workflow_data TEXT NOT NULL,
                created_at INTEGER NOT NULL,
                updated_at INTEGER NOT NULL,
                execution_count INTEGER DEFAULT 0,
                last_execution_at INTEGER,
                tags TEXT
            )
        """
        )

        cursor.execute(
            """
            CREATE TABLE IF NOT EXISTS workflow_executions (
                execution_id TEXT PRIMARY KEY,
                workflow_id TEXT NOT NULL,
                started_at INTEGER NOT NULL,
                completed_at INTEGER,
                status TEXT NOT NULL,
                execution_log TEXT,
                variables TEXT,
                step_results TEXT,
                FOREIGN KEY (workflow_id) REFERENCES workflows(workflow_id)
            )
        """
        )

        cursor.execute(
            """
            CREATE INDEX IF NOT EXISTS idx_workflow_name ON workflows(name)
        """
        )
        cursor.execute(
            """
            CREATE INDEX IF NOT EXISTS idx_execution_workflow ON workflow_executions(workflow_id)
        """
        )
        cursor.execute(
            """
            CREATE INDEX IF NOT EXISTS idx_execution_started ON workflow_executions(started_at)
        """
        )

        conn.commit()
        conn.close()

    def save_workflow(self, workflow: Workflow) -> str:
        import hashlib

        workflow_data = json.dumps(workflow.to_dict())
        workflow_id = hashlib.sha256(workflow.name.encode()).hexdigest()[:16]

        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        current_time = int(time.time())
        tags_json = json.dumps(workflow.tags)

        cursor.execute(
            """
            INSERT OR REPLACE INTO workflows
            (workflow_id, name, description, workflow_data, created_at, updated_at, tags)
            VALUES (?, ?, ?, ?, ?, ?, ?)
        """,
            (
                workflow_id,
                workflow.name,
                workflow.description,
                workflow_data,
                current_time,
                current_time,
                tags_json,
            ),
        )

        conn.commit()
        conn.close()

        return workflow_id

    def load_workflow(self, workflow_id: str) -> Optional[Workflow]:
        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        cursor.execute("SELECT workflow_data FROM workflows WHERE workflow_id = ?", (workflow_id,))
        row = cursor.fetchone()
        conn.close()

        if row:
            workflow_dict = json.loads(row[0])
            return Workflow.from_dict(workflow_dict)
        return None

    def load_workflow_by_name(self, name: str) -> Optional[Workflow]:
        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        cursor.execute("SELECT workflow_data FROM workflows WHERE name = ?", (name,))
        row = cursor.fetchone()
        conn.close()

        if row:
            workflow_dict = json.loads(row[0])
            return Workflow.from_dict(workflow_dict)
        return None

    def list_workflows(self, tag: Optional[str] = None) -> List[dict]:
        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        if tag:
            cursor.execute(
                """
                SELECT workflow_id, name, description, execution_count, last_execution_at, tags
                FROM workflows
                WHERE tags LIKE ?
                ORDER BY name
            """,
                (f'%"{tag}"%',),
            )
        else:
            cursor.execute(
                """
                SELECT workflow_id, name, description, execution_count, last_execution_at, tags
                FROM workflows
                ORDER BY name
            """
            )

        workflows = []
        for row in cursor.fetchall():
            workflows.append(
                {
                    "workflow_id": row[0],
                    "name": row[1],
                    "description": row[2],
                    "execution_count": row[3],
                    "last_execution_at": row[4],
                    "tags": json.loads(row[5]) if row[5] else [],
                }
            )

        conn.close()
        return workflows

    def delete_workflow(self, workflow_id: str) -> bool:
        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        cursor.execute("DELETE FROM workflows WHERE workflow_id = ?", (workflow_id,))
        deleted = cursor.rowcount > 0

        cursor.execute("DELETE FROM workflow_executions WHERE workflow_id = ?", (workflow_id,))

        conn.commit()
        conn.close()

        return deleted

    def save_execution(
        self, workflow_id: str, execution_context: "WorkflowExecutionContext"
    ) -> str:
        import uuid

        execution_id = str(uuid.uuid4())[:16]

        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        started_at = (
            int(execution_context.execution_log[0]["timestamp"])
            if execution_context.execution_log
            else int(time.time())
        )
        completed_at = int(time.time())

        cursor.execute(
            """
            INSERT INTO workflow_executions
            (execution_id, workflow_id, started_at, completed_at, status, execution_log, variables, step_results)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?)
        """,
            (
                execution_id,
                workflow_id,
                started_at,
                completed_at,
                "completed",
                json.dumps(execution_context.execution_log),
                json.dumps(execution_context.variables),
                json.dumps(execution_context.step_results),
            ),
        )

        cursor.execute(
            """
            UPDATE workflows
            SET execution_count = execution_count + 1,
                last_execution_at = ?
            WHERE workflow_id = ?
        """,
            (completed_at, workflow_id),
        )

        conn.commit()
        conn.close()

        return execution_id

    def get_execution_history(self, workflow_id: str, limit: int = 10) -> List[dict]:
        conn = sqlite3.connect(self.db_path, check_same_thread=False)
        cursor = conn.cursor()

        cursor.execute(
            """
            SELECT execution_id, started_at, completed_at, status
            FROM workflow_executions
            WHERE workflow_id = ?
            ORDER BY started_at DESC
            LIMIT ?
        """,
            (workflow_id, limit),
        )

        executions = []
        for row in cursor.fetchall():
            executions.append(
                {
                    "execution_id": row[0],
                    "started_at": row[1],
                    "completed_at": row[2],
                    "status": row[3],
                }
            )

        conn.close()
        return executions