import secrets
from datetime import datetime, timezone

from fastapi import APIRouter, Depends, Form, Request
from fastapi.responses import HTMLResponse, RedirectResponse
import aiosqlite

from app.database import get_db
from app.dependencies import require_admin
from app.templates_config import templates

router = APIRouter()


async def _get_course_detail(cid: str, db: aiosqlite.Connection):
    """Returns (course_dict, holes_list, tees_list) or (None, [], [])."""
    async with db.execute(
        "SELECT id, name, holes, location FROM courses WHERE id = ?", (cid,)
    ) as c:
        course = await c.fetchone()
    if not course:
        return None, [], []
    async with db.execute(
        "SELECT hole_number, par, stroke_index FROM course_holes WHERE course_id = ? ORDER BY hole_number",
        (cid,),
    ) as c:
        holes = [dict(r) for r in await c.fetchall()]
    async with db.execute(
        "SELECT id, name, slope, rating FROM course_tees WHERE course_id = ? ORDER BY name",
        (cid,),
    ) as c:
        tees = [dict(r) for r in await c.fetchall()]
    return dict(course), holes, tees


# ── List ──────────────────────────────────────────────────────────────────────

@router.get("/admin/courses", response_class=HTMLResponse)
async def courses_page(request: Request, user: dict = Depends(require_admin),
                       db: aiosqlite.Connection = Depends(get_db)):
    async with db.execute(
        "SELECT id, name, holes, location FROM courses ORDER BY name"
    ) as c:
        courses = [dict(r) for r in await c.fetchall()]
    return templates.TemplateResponse(
        "admin/courses.html",
        {"request": request, "user": user, "courses": courses},
    )


# ── Create ────────────────────────────────────────────────────────────────────

@router.get("/admin/courses/new", response_class=HTMLResponse)
async def new_course_page(request: Request, user: dict = Depends(require_admin)):
    return templates.TemplateResponse(
        "admin/new_course.html", {"request": request, "user": user}
    )


@router.post("/admin/courses/new")
async def create_course(request: Request,
                        name: str = Form(...), holes: int = Form(...),
                        location: str = Form(""),
                        user: dict = Depends(require_admin),
                        db: aiosqlite.Connection = Depends(get_db)):
    form = await request.form()
    name = name.strip()
    location = location.strip()
    errors = {}
    if not name:
        errors["name"] = "Name is required."
    if holes not in (9, 18):
        errors["holes"] = "Holes must be 9 or 18."

    hole_count = holes if holes in (9, 18) else 18
    pars = {}
    stroke_indices = {}
    for i in range(1, hole_count + 1):
        raw = form.get(f"par_{i}", "4")
        try:
            p = int(raw)
            if p < 3 or p > 5:
                errors[f"par_{i}"] = f"Hole {i}: par must be 3–5."
            else:
                pars[i] = p
        except (ValueError, TypeError):
            errors[f"par_{i}"] = f"Hole {i}: invalid par."
        raw_si = form.get(f"si_{i}", "")
        if raw_si:
            try:
                si = int(raw_si)
                if si < 1 or si > hole_count:
                    errors[f"si_{i}"] = f"Hole {i}: SI must be 1–{hole_count}."
                else:
                    stroke_indices[i] = si
            except (ValueError, TypeError):
                errors[f"si_{i}"] = f"Hole {i}: invalid SI."
        else:
            stroke_indices[i] = None

    if errors:
        return templates.TemplateResponse(
            "admin/new_course.html",
            {"request": request, "user": user, "errors": errors,
             "form": {"name": name, "holes": holes, "location": location,
                      "pars": pars, "stroke_indices": stroke_indices}},
            status_code=422,
        )

    cid = secrets.token_urlsafe(10)
    now = datetime.now(timezone.utc).isoformat()
    await db.execute(
        "INSERT INTO courses (id, name, holes, location, created_at) VALUES (?,?,?,?,?)",
        (cid, name, holes, location or None, now),
    )
    for hole_num, par in pars.items():
        await db.execute(
            "INSERT INTO course_holes (id, course_id, hole_number, par, stroke_index) VALUES (?,?,?,?,?)",
            (secrets.token_urlsafe(10), cid, hole_num, par, stroke_indices.get(hole_num)),
        )
    await db.commit()
    return RedirectResponse(
        f"/admin/courses/{cid}/edit?success=Course+created.+Add+tees+below.",
        status_code=302,
    )


# ── Edit ──────────────────────────────────────────────────────────────────────

@router.get("/admin/courses/{cid}/edit", response_class=HTMLResponse)
async def edit_course_page(cid: str, request: Request,
                           user: dict = Depends(require_admin),
                           db: aiosqlite.Connection = Depends(get_db)):
    course, holes, tees = await _get_course_detail(cid, db)
    if not course:
        return RedirectResponse("/admin/courses", status_code=302)
    return templates.TemplateResponse(
        "admin/edit_course.html",
        {"request": request, "user": user, "course": course, "holes": holes, "tees": tees},
    )


@router.post("/admin/courses/{cid}/edit")
async def edit_course_submit(cid: str, request: Request,
                             name: str = Form(...), holes: int = Form(...),
                             location: str = Form(""),
                             user: dict = Depends(require_admin),
                             db: aiosqlite.Connection = Depends(get_db)):
    form = await request.form()
    course, existing_holes, tees = await _get_course_detail(cid, db)
    if not course:
        return RedirectResponse("/admin/courses", status_code=302)

    name = name.strip()
    location = location.strip()
    errors = {}
    if not name:
        errors["name"] = "Name is required."
    if holes not in (9, 18):
        errors["holes"] = "Holes must be 9 or 18."

    hole_count = holes if holes in (9, 18) else 18
    pars = {}
    stroke_indices = {}
    for i in range(1, hole_count + 1):
        raw = form.get(f"par_{i}", "4")
        try:
            p = int(raw)
            if p < 3 or p > 5:
                errors[f"par_{i}"] = f"Hole {i}: par must be 3–5."
            else:
                pars[i] = p
        except (ValueError, TypeError):
            errors[f"par_{i}"] = f"Hole {i}: invalid par."
        raw_si = form.get(f"si_{i}", "")
        if raw_si:
            try:
                si = int(raw_si)
                if si < 1 or si > hole_count:
                    errors[f"si_{i}"] = f"Hole {i}: SI must be 1–{hole_count}."
                else:
                    stroke_indices[i] = si
            except (ValueError, TypeError):
                errors[f"si_{i}"] = f"Hole {i}: invalid SI."
        else:
            stroke_indices[i] = None

    if errors:
        return templates.TemplateResponse(
            "admin/edit_course.html",
            {"request": request, "user": user, "course": course,
             "holes": existing_holes, "tees": tees, "errors": errors},
            status_code=422,
        )

    await db.execute(
        "UPDATE courses SET name = ?, holes = ?, location = ? WHERE id = ?",
        (name, holes, location or None, cid),
    )
    for hole_num, par in pars.items():
        await db.execute(
            """INSERT INTO course_holes (id, course_id, hole_number, par, stroke_index) VALUES (?,?,?,?,?)
               ON CONFLICT(course_id, hole_number) DO UPDATE SET
                 par=excluded.par, stroke_index=excluded.stroke_index""",
            (secrets.token_urlsafe(10), cid, hole_num, par, stroke_indices.get(hole_num)),
        )
    # Remove holes beyond new count if holes was reduced
    await db.execute(
        "DELETE FROM course_holes WHERE course_id = ? AND hole_number > ?", (cid, holes)
    )
    await db.commit()
    return RedirectResponse(f"/admin/courses/{cid}/edit?success=Course+updated.", status_code=302)


# ── Delete course ─────────────────────────────────────────────────────────────

@router.post("/admin/courses/{cid}/delete")
async def delete_course(cid: str, user: dict = Depends(require_admin),
                        db: aiosqlite.Connection = Depends(get_db)):
    await db.execute("DELETE FROM course_holes WHERE course_id = ?", (cid,))
    await db.execute("DELETE FROM course_tees WHERE course_id = ?", (cid,))
    await db.execute("DELETE FROM courses WHERE id = ?", (cid,))
    await db.commit()
    return RedirectResponse("/admin/courses?success=Course+deleted.", status_code=302)


# ── Tees ──────────────────────────────────────────────────────────────────────

@router.post("/admin/courses/{cid}/tees/new")
async def add_tee(cid: str, name: str = Form(...),
                  slope: int = Form(...), rating: float = Form(...),
                  user: dict = Depends(require_admin),
                  db: aiosqlite.Connection = Depends(get_db)):
    await db.execute(
        "INSERT INTO course_tees (id, course_id, name, slope, rating) VALUES (?,?,?,?,?)",
        (secrets.token_urlsafe(10), cid, name.strip(), slope, rating),
    )
    await db.commit()
    return RedirectResponse(f"/admin/courses/{cid}/edit?success=Tee+added.", status_code=302)


@router.post("/admin/courses/{cid}/tees/{tid}/edit")
async def edit_tee(cid: str, tid: str, name: str = Form(...),
                   slope: int = Form(...), rating: float = Form(...),
                   user: dict = Depends(require_admin),
                   db: aiosqlite.Connection = Depends(get_db)):
    await db.execute(
        "UPDATE course_tees SET name = ?, slope = ?, rating = ? WHERE id = ? AND course_id = ?",
        (name.strip(), slope, rating, tid, cid),
    )
    await db.commit()
    return RedirectResponse(f"/admin/courses/{cid}/edit?success=Tee+updated.", status_code=302)


@router.post("/admin/courses/{cid}/tees/{tid}/delete")
async def delete_tee(cid: str, tid: str, user: dict = Depends(require_admin),
                     db: aiosqlite.Connection = Depends(get_db)):
    # Nullify references in game_players before deleting
    await db.execute(
        "UPDATE game_players SET tee_id = NULL WHERE tee_id = ?", (tid,)
    )
    await db.execute(
        "DELETE FROM course_tees WHERE id = ? AND course_id = ?", (tid, cid)
    )
    await db.commit()
    return RedirectResponse(f"/admin/courses/{cid}/edit?success=Tee+deleted.", status_code=302)