import os
import json
import uuid
from typing import Optional
from datetime import datetime
from fastapi import FastAPI, HTTPException, Path
from pydantic import BaseModel, Field
import argparse
import uvicorn

app = FastAPI(title="Tour Voting API")

# ─── Pydantic MODELS ──────────────────────────────────────────────────────────

class Idea(BaseModel):
    id: str
    name: str
    start_time: Optional[datetime] = None
    end_time:   Optional[datetime] = None
    description: str
    voters: list[str] = Field(default_factory=list)

class Tour(BaseModel):
    id: str
    name: str
    start_date: Optional[datetime] = None
    end_date:   Optional[datetime] = None
    description: str
    ideas: list[Idea] = Field(default_factory=list)
    createdAt: datetime

class TourCreate(BaseModel):
    name: str
    start_date: Optional[datetime] = None
    end_date:   Optional[datetime] = None
    description: str

class IdeaCreate(BaseModel):
    name: str
    start_time: Optional[datetime] = None
    end_time:   Optional[datetime] = None
    description: str

class Vote(BaseModel):
    voterName: str

# ─── GLOBAL CONFIG ────────────────────────────────────────────────────────────

DATA_DIR = ""  # will be overridden via command line

def get_tour_filepath(tour_id: str) -> str:
    return os.path.join(DATA_DIR, f"{tour_id}.json")

# ─── ENDPOINT: CREATE TOUR ─────────────────────────────────────────────────────

@app.post("/tour/v1/tours", response_model=Tour)
def create_tour(tour: TourCreate):
    """
    Create a new tour. Generates its own UUID and timestamp, then writes to {tour_id}.json.
    """
    tour_id = str(uuid.uuid4())
    created_at = datetime.utcnow()

    new_tour = Tour(
        id=tour_id,
        name=tour.name,
        start_date=tour.start_date,
        end_date=tour.end_date,
        description=tour.description,
        ideas=[],
        createdAt=created_at,
    )

    filepath = get_tour_filepath(tour_id)
    with open(filepath, "w") as f:
        # Using default=str so that datetime objects become ISO strings
        json.dump(new_tour.dict(), f, default=str)

    return new_tour

# ─── ENDPOINT: GET TOUR ────────────────────────────────────────────────────────

@app.get("/tour/v1/tours/{tour_id}", response_model=Tour)
def get_tour(tour_id: str = Path(...)):
    """
    Retrieve an existing tour by ID. Loads {tour_id}.json and parses back into a Tour.
    """
    filepath = get_tour_filepath(tour_id)
    if not os.path.exists(filepath):
        raise HTTPException(status_code=404, detail="Tour not found")

    with open(filepath) as f:
        data = json.load(f)

    if data.get("start_date"):
        data["start_date"] = datetime.fromisoformat(data["start_date"])
    if data.get("end_date"):
        data["end_date"] = datetime.fromisoformat(data["end_date"])
    data["createdAt"] = datetime.fromisoformat(data["createdAt"])

    # Convert nested idea timestamps as well
    for idea in data["ideas"]:
        if idea.get("start_time"):
            idea["start_time"] = datetime.fromisoformat(idea["start_time"])
        if idea.get("end_time"):
            idea["end_time"] = datetime.fromisoformat(idea["end_time"])
    return Tour(**data)

# ─── ENDPOINT: ADD IDEA ─────────────────────────────────────────────────────────

@app.post("/tour/v1/tours/{tour_id}/ideas", response_model=Idea)
def add_idea(tour_id: str, idea: IdeaCreate):
    """
    Add a new idea to the given tour. Generates a new UUID for the idea and appends it.
    """
    filepath = get_tour_filepath(tour_id)
    if not os.path.exists(filepath):
        raise HTTPException(status_code=404, detail="Tour not found")

    with open(filepath) as f:
        data = json.load(f)

    idea_id = str(uuid.uuid4())
    new_idea = Idea(
        id=idea_id,
        name=idea.name,
        description=idea.description,
        voters=[],
        start_time=idea.start_time,
        end_time=idea.end_time,
    )

    data["ideas"].append(new_idea.dict())
    with open(filepath, "w") as f:
        json.dump(data, f, default=str)

    return new_idea

# ─── ENDPOINT: VOTE FOR IDEA ───────────────────────────────────────────────────

@app.post("/tour/v1/tours/{tour_id}/ideas/{idea_id}/vote", response_model=Idea)
def vote_idea(tour_id: str, idea_id: str, vote: Vote):
    """
    Cast a vote on a specific idea. Adds voterName if not already present.
    """
    filepath = get_tour_filepath(tour_id)
    if not os.path.exists(filepath):
        raise HTTPException(status_code=404, detail="Tour not found")

    with open(filepath) as f:
        data = json.load(f)

    for idea in data["ideas"]:
        if idea["id"] == idea_id:
            if vote.voterName not in idea["voters"]:
                idea["voters"].append(vote.voterName)
                # Persist the change
                with open(filepath, "w") as f:
                    json.dump(data, f, default=str)
            return Idea(**idea)

    raise HTTPException(status_code=404, detail="Idea not found")

# ─── MAIN: RUN UVIDORN WITH COMMAND-LINE DATA DIR ──────────────────────────────

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Run Tour Voting API server")
    parser.add_argument(
        "--data-dir",
        required=True,
        help="Directory in which to store tour JSON files (one file per tour_id)",
    )
    parser.add_argument(
        "--host",
        default="0.0.0.0",
        help="Host to run the server on",
    )
    parser.add_argument(
        "--port",
        type=int,
        default=8000,
        help="Port to run the server on",
    )
    args = parser.parse_args()

    DATA_DIR = args.data_dir
    os.makedirs(DATA_DIR, exist_ok=True)

    uvicorn.run(app, host=args.host, port=args.port, reload=False)