import os

from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse, JSONResponse
from fastapi.staticfiles import StaticFiles
from sqlalchemy import text, inspect as sa_inspect

from .database import Base, engine, SessionLocal
from .routers import bundles, connectors, diagrams, devices, export, formboard, git_mgr, octopart, views, wires

Base.metadata.create_all(bind=engine)

# Lightweight column migrations (SQLite ALTER TABLE IF NOT EXISTS unsupported)
def _migrate():
    import sys

    # ── Column additions ────────────────────────────────────────────────────────
    try:
        with engine.connect() as conn:
            def _cols(table):
                return {c["name"] for c in sa_inspect(engine).get_columns(table)}

            if "waypoints" not in _cols("wires"):
                conn.execute(text("ALTER TABLE wires ADD COLUMN waypoints TEXT DEFAULT '[]'"))
                conn.commit()
            if "sheet_id" not in _cols("devices"):
                conn.execute(text("ALTER TABLE devices ADD COLUMN sheet_id INTEGER REFERENCES sheets(id)"))
                conn.commit()
            if "sheet_id" not in _cols("wires"):
                conn.execute(text("ALTER TABLE wires ADD COLUMN sheet_id INTEGER REFERENCES sheets(id)"))
                conn.commit()
            if "twisted_pair" not in _cols("wires"):
                conn.execute(text("ALTER TABLE wires ADD COLUMN twisted_pair INTEGER DEFAULT 0"))
                conn.commit()
            if "twist_pitch" not in _cols("wires"):
                conn.execute(text("ALTER TABLE wires ADD COLUMN twist_pitch REAL DEFAULT 16.0"))
                conn.commit()
            if "shielded" not in _cols("wires"):
                conn.execute(text("ALTER TABLE wires ADD COLUMN shielded INTEGER DEFAULT 0"))
                conn.commit()
            if "bundle_id" not in _cols("wires"):
                conn.execute(text("ALTER TABLE wires ADD COLUMN bundle_id INTEGER REFERENCES wire_bundles(id)"))
                conn.commit()
            if "show_size_label" not in _cols("wires"):
                conn.execute(text("ALTER TABLE wires ADD COLUMN show_size_label INTEGER DEFAULT 0"))
                conn.commit()

            # diagram_views / view_device_positions / view_wire_waypoints are created
            # via Base.metadata.create_all — no ALTER TABLE needed for new tables
    except Exception as e:
        print(f"[migrate] column error: {e}", file=sys.stderr)

_migrate()

app = FastAPI(title="Wiring Diagram Maker", version="1.0.0")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

app.include_router(bundles.router,   prefix="/api/bundles")
app.include_router(diagrams.router,  prefix="/api/diagrams")
app.include_router(devices.router,   prefix="/api/devices")
app.include_router(wires.router,     prefix="/api/wires")
app.include_router(views.router,     prefix="/api/views")
app.include_router(octopart.router,  prefix="/api/octopart")
app.include_router(export.router,    prefix="/api/export")
app.include_router(connectors.router, prefix="/api/connectors")
app.include_router(formboard.router,  prefix="/api/formboard")
app.include_router(git_mgr.router,   prefix="/api/git")

FRONTEND_DIR = os.path.normpath(
    os.path.join(os.path.dirname(__file__), "..", "..", "frontend")
)

if os.path.isdir(FRONTEND_DIR):
    for _sub in ("css", "js"):
        _d = os.path.join(FRONTEND_DIR, _sub)
        if os.path.isdir(_d):
            app.mount(f"/{_sub}", StaticFiles(directory=_d), name=_sub)

    _index = os.path.join(FRONTEND_DIR, "index.html")

    @app.get("/")
    async def _root():
        return FileResponse(_index)

    @app.exception_handler(404)
    async def _spa_fallback(request: Request, exc):
        if request.url.path.startswith("/api"):
            return JSONResponse(status_code=404, content={"detail": "Not Found"})
        return FileResponse(_index)