from contextlib import asynccontextmanager
from pathlib import Path
from typing import Any
from datetime import date, datetime
import os

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel, Field

import db
import graph
from parser import CsvValidationError, parse_target_csv
from scheduler import SchedulerTest, compile_schedule, remove_from_active, reset_scheduler_state
from watcher import configure_result_watcher, stop_result_watcher


APP_ROOT = Path(__file__).resolve().parent
DB_PATH = APP_ROOT / "scheduler.db"
DUT = os.getenv("DUT", "CGW453").strip()
REF = os.getenv("REF", "CGW452").strip()


class LoadTestsRequest(BaseModel):
	csv_path: str = Field(..., description="Absolute or backend-relative path to target CSV")


class SaveSettingsRequest(BaseModel):
	settings: dict[str, Any]


def _smb_credentials_from_settings(settings: dict[str, Any]) -> dict[str, str]:
	return {
		"username": str(settings.get("smbUsername") or "").strip(),
		"password": str(settings.get("smbPassword") or ""),
		"domain": str(settings.get("smbDomain") or "").strip(),
	}


def _runtime_overrides_from_settings(settings: dict[str, Any]) -> dict[str, int]:
	def _parse_positive_int(value: Any) -> int | None:
		if value is None:
			return None
		if isinstance(value, str):
			value = value.strip()
			if not value:
				return None
		try:
			parsed = int(value)
		except (TypeError, ValueError):
			return None
		return parsed if parsed > 0 else None

	overrides: dict[str, int] = {}
	for test_type, key in (
		("P2P", "p2pRuntimeMinutes"),
		("COE", "coeRuntimeMinutes"),
		("P3P", "p3pRuntimeMinutes"),
	):
		minutes = _parse_positive_int(settings.get(key))
		if minutes is not None:
			overrides[test_type] = minutes

	return overrides


class CompileScheduleRequest(BaseModel):
	start_date: str | None = Field(default=None, description="YYYY-MM-DD")
	rule: str = ""
	daytime_testing_today: bool = False
	top_priority_tests: list[str] = Field(default_factory=list)
	lowest_priority_tests: list[str] = Field(default_factory=list)


class RemoveActiveTestsRequest(BaseModel):
	test_ids: list[str] = Field(default_factory=list)


class SaveHolidaysRequest(BaseModel):
	dates: list[str] = Field(default_factory=list)


@asynccontextmanager
async def lifespan(application: FastAPI):
	db.init_db(DB_PATH)
	graph.reset_graph_state()
	settings = db.read_settings(DB_PATH)
	configure_result_watcher(settings)
	try:
		yield
	finally:
		stop_result_watcher()


app = FastAPI(title="Scheduler API", version="0.1.0", lifespan=lifespan)

app.add_middleware(
	CORSMiddleware,
	allow_origins=["http://localhost:5173", "http://127.0.0.1:5173"],
	allow_methods=["*"],
	allow_headers=["*"],
)


@app.get("/api/health")
def health() -> dict[str, str]:
	return {"status": "ok"}


@app.post("/api/settings")
def save_settings(request: SaveSettingsRequest) -> dict[str, str]:
	db.save_settings(request.settings, DB_PATH)
	configure_result_watcher(db.read_settings(DB_PATH))
	return {"status": "saved"}


@app.get("/api/settings")
def get_settings() -> dict[str, Any]:
	return db.read_settings(DB_PATH)


@app.post("/api/tests/load")
def load_tests(request: LoadTestsRequest) -> dict[str, Any]:
	csv_path = Path(request.csv_path)
	if not csv_path.is_absolute():
		csv_path = APP_ROOT / csv_path

	settings = db.read_settings(DB_PATH)
	smb_credentials = _smb_credentials_from_settings(settings)
	runtime_overrides = _runtime_overrides_from_settings(settings)

	try:
		parsed = parse_target_csv(
			csv_path,
			smb_credentials=smb_credentials,
			runtime_overrides=runtime_overrides,
		)
	except FileNotFoundError as exc:
		raise HTTPException(status_code=404, detail=str(exc)) from exc
	except CsvValidationError as exc:
		raise HTTPException(status_code=400, detail=str(exc)) from exc

	count = db.upsert_tests(parsed.tests, DB_PATH)
	reset_scheduler_state()
	graph.reset_graph_state()
	all_dut_tests = db.list_tests_for_device(DUT, DB_PATH)
	graph.build_and_persist_graph(all_dut_tests, DB_PATH)

	return {
		"loaded_tests": count,
		"warnings": parsed.warnings,
		"dut_graph_nodes": len(graph.get_graph()),
	}


@app.post("/api/schedule/active/remove")
def remove_active_tests(request: RemoveActiveTestsRequest) -> dict[str, Any]:
	remove_from_active({item.strip() for item in request.test_ids if item.strip()})
	return {"status": "ok", "removed": len(request.test_ids)}


@app.post("/api/schedule/compile")
def compile_schedule_endpoint(request: CompileScheduleRequest) -> dict[str, Any]:
	if request.start_date:
		try:
			datetime.strptime(request.start_date, "%Y-%m-%d")
		except ValueError as exc:
			raise HTTPException(status_code=400, detail="start_date must be YYYY-MM-DD") from exc

	reset_scheduler_state()
	stored_tests = db.list_schedulable_tests(DB_PATH, rule=request.rule)
	if not stored_tests:
		version = db.create_schedule_version([], DB_PATH)
		return {
			"schedule_version": version,
			"scheduled_tests": 0,
			"completion_date": None,
		}

	scheduler_tests = [
		SchedulerTest(
			test_id=t.test_id,
			device=t.device,
			test_type=t.test_type,
			rotation=t.rotation,
			rx_tx=t.rx_tx,
			has_coe_pair=t.has_coe_pair,
			coe_pairing=t.coe_pairing or [],
			config=t.config,
			throttled=t.throttled,
			estimated_minutes=t.estimated_minutes,
			priority=t.priority,
			raw_payload=t.raw_payload or {},
		)
		for t in stored_tests
	]

	# DB-backed graph retrieval ensures compile works after restart without manual save/load.
	all_dut_tests = db.list_tests_for_device(DUT, DB_PATH)
	graph.get_graph(DB_PATH, all_dut_tests)

	holiday_dates = db.list_holidays(DB_PATH)
	try:
		entries, completion_date = compile_schedule(
			tests=scheduler_tests,
			start_date=request.start_date,
			holiday_dates=holiday_dates,
			top_priority_tests={item.strip() for item in request.top_priority_tests if item.strip()},
			lowest_priority_tests={item.strip() for item in request.lowest_priority_tests if item.strip()},
			daytime_testing_today=request.daytime_testing_today,
		)
	except RuntimeError as exc:
		raise HTTPException(status_code=409, detail=str(exc)) from exc

	version = db.create_schedule_version(
		[(e.test_id, e.device, e.scheduled_date, e.shift_index, e.sequence_in_shift) for e in entries],
		DB_PATH,
	)
	print(f"Schedule version {version} created with {len(entries)} entries, completion date: {completion_date}")
	return {
		"schedule_version": version,
		"scheduled_tests": len(entries),
		"completion_date": completion_date,
	}


@app.get("/api/tests/rerun")
def get_rerun_tests() -> dict[str, Any]:
	db.mark_overdue_as_rerun(DB_PATH)
	tests = db.get_rerun_tests(DB_PATH)
	total_minutes = sum(t["estimated_minutes"] for t in tests)
	return {"tests": tests, "total_estimated_minutes": total_minutes}


@app.post("/api/holidays")
def save_holidays(request: SaveHolidaysRequest) -> dict[str, Any]:
	dates = [d.strip() for d in request.dates if d.strip()]
	db.upsert_holidays(dates, DB_PATH)
	return {"status": "saved", "count": len(dates)}


@app.get("/api/holidays")
def get_holidays() -> dict[str, Any]:
	return {"dates": sorted(db.list_holidays(DB_PATH))}


@app.get("/api/schedule/week")
def get_schedule_week(start: str | None = None) -> dict[str, Any]:
	week_start = start or date.today().isoformat()
	try:
		datetime.strptime(week_start, "%Y-%m-%d")
	except ValueError as exc:
		raise HTTPException(status_code=400, detail="start must be YYYY-MM-DD") from exc

	rows = db.get_schedule_week(week_start, DB_PATH)
	return {
		"start_date": week_start,
		"items": [
			{
				"test_id": row.test_id,
				"device": row.device,
				"scheduled_date": row.scheduled_date,
				"shift_index": row.shift_index,
				"sequence_in_shift": row.sequence_in_shift,
				"test_type": row.test_type,
				"rotation": row.rotation,
				"config": row.config,
				"status": row.status,
				"priority": row.priority,
				"estimated_minutes": row.estimated_minutes,
			}
			for row in rows
		],
	}

if __name__ == "__main__":
    import uvicorn
    uvicorn.run("app:app", host="0.0.0.0", port=8000, reload=True)