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

from fastapi import FastAPI, HTTPException
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


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

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


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


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


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)


@app.on_event("startup")
def on_startup() -> None:
	db.init_db(DB_PATH)
	graph.reset_graph_state()


@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)
	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

	try:
		parsed = parse_target_csv(csv_path)
	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_graph_once(all_dut_tests)

	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

	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,
			estimated_minutes=t.estimated_minutes,
			priority=t.priority,
			raw_payload=t.raw_payload or {},
		)
		for t in stored_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,
	)

	return {
		"schedule_version": version,
		"scheduled_tests": len(entries),
		"completion_date": completion_date,
	}


@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,
				"status": row.status,
				"priority": row.priority,
				"estimated_minutes": row.estimated_minutes,
			}
			for row in rows
		],
	}