from typing import Optional, List
from fastapi import FastAPI, Header, HTTPException
from pydantic import BaseModel
import datetime
import databases
import sqlalchemy
from sqlite3 import OperationalError

API_VERSION_MAJOR = 1
API_VERSION_MINOR = 0

REST_API_ROOT = f"/energy/v{API_VERSION_MAJOR}/"
REST_API_VERSION = REST_API_ROOT + ".0"

DATABASE_URL = "sqlite:///./energyDB.sqlite"
# DATABASE_URL = "sqlite://"
db = databases.Database(DATABASE_URL)
metadata = sqlalchemy.MetaData()
energy = sqlalchemy.Table(
    "energy",
    metadata,
    sqlalchemy.Column("timestamp", sqlalchemy.DateTime, primary_key=True),
    sqlalchemy.Column("channel_id", sqlalchemy.Integer(), nullable=False),
    sqlalchemy.Column("value", sqlalchemy.Float),
    sqlalchemy.UniqueConstraint("timestamp"),
)
engine = sqlalchemy.create_engine(
    DATABASE_URL, connect_args={"check_same_thread": False}
)
metadata.create_all(engine)

class EnergyValue(BaseModel):
    timestamp: datetime.datetime
    value: float

class ChannelData(BaseModel):
    channel_id: int
    data: List[EnergyValue]
    msg: Optional[str]

class BulkData(BaseModel):
    bulk: List[ChannelData]
    msg: Optional[str]

class BulkDataRequest(BaseModel):
    channel_ids: List[int]
    fromTime: datetime.datetime
    tillTime: datetime.datetime = datetime.datetime.now()

app = FastAPI(debug=True)

@app.on_event("startup")
async def startup():
    """On startup connect to the database"""
    await db.connect()

@app.on_event("shutdown")
async def shutdown():
    """On shutdow diconnect from the database"""
    await db.disconnect()

# def _raiseHttpExceptionOnWrongToken(token : str):
#     if token != fake_secret_token:
#         raise HTTPException(status_code=400, detail="Invalid X-Token header")

@app.put(REST_API_ROOT + "bulkData")
async def putBulkEnergyData(bulkData: BulkData):
    valuesToInsert = []
    for channelData in bulkData.bulk:
        for measurement in channelData.data:
            valuesToInsert.append({
                "channel_id": channelData.channel_id,
                "timestamp": measurement.timestamp,
                "value": measurement.value})
    query = energy.insert().values(valuesToInsert)
    result = await db.execute(query)
    return {
        "valuesToInsert": valuesToInsert
    }

@app.get(REST_API_ROOT + "bulkData", response_model = BulkData)
async def getBulkEnergyData(bulkDataRequest: BulkDataRequest):
    bulkData = []
    for ch in bulkDataRequest.channel_ids:
        query = sqlalchemy.select([energy.c.timestamp, energy.c.value]) \
                          .where(energy.c.channel_id == ch) \
                          .where(energy.c.timestamp >= bulkDataRequest.fromTime) \
                          .where(energy.c.timestamp <= bulkDataRequest.tillTime)
        data = await db.fetch_all(query)
        bulkData.append({"channel_id": ch, "data": data})

    return {
        "bulk": bulkData,
        "msg": __name__ + " - " +str(query.compile())
        }


@app.get("/energy/{channel_id}", response_model = ChannelData)
async def getChannelData(channel_id: int):
    try:
        query = sqlalchemy.select([energy.c.timestamp, energy.c.value]).where(energy.c.channel_id == channel_id)
        result = await db.fetch_all(query)
        return {
            "channel_id": channel_id,
            "data":    result
        }
    except Exception as ex:
        raise HTTPException(status_code=500, detail=f"Internal error: {type(ex)} - \"{ex}\"")

@app.put("/energy/{channel_id}") #, response_model = EnergyValue)
async def putChannelData(channel_id: int, data: EnergyValue):
    query = energy.insert().values(
        timestamp=data.timestamp,
        channel_id=channel_id,
        value=data.value)
    result = await db.execute(query)
    # # return await db.fetch_all(query)
    return {
        "timestamp": datetime.datetime.now(),
        # "channel" : data.channel,
        "value": data.value,
        "msg": str(result)
    }