package web

import (
	"encoding/json"
	"errors"
	"io"
	"log/slog"
	"net/http"
	"strings"
	"time"

	"pete/internal/storage"
)

// buyerLocalpart normalises a session's Authentik username to the Matrix
// localpart gogobee keys everything on. Matrix localparts are lowercase; an
// Authentik display of the same name may not be, and gogobee pushes balances and
// resolves orders under the lowercase form. Lowercasing on both sides is what
// keeps the buyer's balance lookup and their order's identity pointing at the
// same person.
func buyerLocalpart(u *SessionUser) string {
	return strings.ToLower(strings.TrimSpace(u.Username))
}

// The mischief storefront's web seam.
//
// Two audiences, two auth models, same file. Browsers hit the OIDC-gated buy
// endpoints: a signed-in buyer picks a mark off the anonymous board and places a
// hit, and reads back their own orders' standing. gogobee hits the bearer-authed
// pair: it polls pending orders and pushes a verdict, exactly like the escrow
// seam in games.go and under the same standing rule — Pete never calls gogobee,
// never moves money, never runs a game rule. It records intent and files a
// verdict; everything real happens on the game box.

// mischiefBurstWindow / mischiefBurstMax are Pete's own anti-spam guard, and
// nothing more. The real economic caps — two contracts a day, one live per mark,
// a boss a week — are gogobee's and are enforced at claim time. This only stops a
// signed-in buyer from spooling the orders table with a stuck mouse button.
const (
	mischiefBurstWindow = time.Hour
	mischiefBurstMax    = 20
)

// mischiefOrderReq is the browser's buy request. Price and eligibility are not
// the buyer's to assert: they send a tier key and a mark, never a number.
type mischiefOrderReq struct {
	TargetToken string `json:"target_token"`
	Tier        string `json:"tier"`
	Signed      bool   `json:"signed"`
}

// handleMischiefOrder places a pending order for the signed-in buyer. It asserts
// only what Pete can honestly know: the buyer is signed in with a username the
// game box can resolve, the tier is one gogobee currently offers, and the mark is
// actually on the live board. Money and the full rulebook are gogobee's, checked
// when it claims the order.
func (s *Server) handleMischiefOrder(w http.ResponseWriter, r *http.Request) {
	u := s.requireUser(w, r)
	if u == nil {
		return
	}
	// A session minted before the storefront existed carries no username, and
	// without one gogobee can't name the buyer to its ledger. Send them back
	// through sign-in to mint a fresh one rather than place an unfulfillable order.
	buyer := buyerLocalpart(u)
	if buyer == "" {
		writeMischiefError(w, http.StatusConflict, "please sign in again")
		return
	}

	var req mischiefOrderReq
	if !decodeStateBody(w, r, &req) {
		return
	}
	if req.TargetToken == "" {
		writeMischiefError(w, http.StatusBadRequest, "no target")
		return
	}

	tier, ok, err := storage.MischiefTierByKey(req.Tier)
	if err != nil {
		slog.Error("mischief: tier lookup", "err", err)
		writeMischiefError(w, http.StatusInternalServerError, "internal error")
		return
	}
	if !ok {
		writeMischiefError(w, http.StatusBadRequest, "no such tier")
		return
	}

	mark, ok, err := storage.RosterEntryByToken(req.TargetToken)
	if err != nil {
		slog.Error("mischief: target lookup", "err", err)
		writeMischiefError(w, http.StatusInternalServerError, "internal error")
		return
	}
	if !ok {
		// The board moved on, or the token was never real. Either way there is no
		// one to send trouble to.
		writeMischiefError(w, http.StatusNotFound, "that adventurer is no longer on the board")
		return
	}

	// Burst guard. Keyed on the OIDC subject so a username change can't reset it.
	since := time.Now().Add(-mischiefBurstWindow).Unix()
	if n, err := storage.CountMischiefOrdersSince(u.Sub, since); err != nil {
		slog.Error("mischief: burst count", "err", err)
		writeMischiefError(w, http.StatusInternalServerError, "internal error")
		return
	} else if n >= mischiefBurstMax {
		writeMischiefError(w, http.StatusTooManyRequests, "slow down — too many orders in a short while")
		return
	}

	order, err := storage.InsertMischiefOrder(u.Sub, buyer, mark.Token, mark.Name, tier.Key, req.Signed)
	if err != nil {
		slog.Error("mischief: insert order", "err", err)
		writeMischiefError(w, http.StatusInternalServerError, "internal error")
		return
	}
	slog.Info("mischief: order placed", "guid", order.GUID, "buyer", buyer, "tier", tier.Key, "signed", req.Signed)
	w.Header().Set("Cache-Control", "no-store")
	writeJSON(w, order)
}

// handleMischiefOrders returns the signed-in buyer's own orders for the status
// panel, newest first. Scoped to their OIDC subject — a buyer sees their history
// and no one else's.
func (s *Server) handleMischiefOrders(w http.ResponseWriter, r *http.Request) {
	u := s.requireUser(w, r)
	if u == nil {
		return
	}
	orders, err := storage.MischiefOrdersByBuyer(u.Sub, 20)
	if err != nil {
		slog.Error("mischief: orders by buyer", "err", err)
		writeMischiefError(w, http.StatusInternalServerError, "internal error")
		return
	}
	if orders == nil {
		orders = []storage.MischiefOrder{}
	}
	w.Header().Set("Cache-Control", "no-store")
	writeJSON(w, orders)
}

// mischiefCatalogResp is what the storefront reads to draw itself: the live price
// list plus the signed-in buyer's own advisory balance, so it can grey out tiers
// they plainly can't afford. HasBalance distinguishes "gogobee says €0" from
// "gogobee has never mentioned this buyer" — the latter shows no affordability
// hint rather than a discouraging, possibly-wrong zero.
type mischiefCatalogResp struct {
	Tiers      []storage.MischiefTier `json:"tiers"`
	Euro       float64                `json:"euro"`
	HasBalance bool                   `json:"has_balance"`
}

// handleMischiefCatalog serves the price list and the buyer's balance together.
func (s *Server) handleMischiefCatalog(w http.ResponseWriter, r *http.Request) {
	u := s.requireUser(w, r)
	if u == nil {
		return
	}
	tiers, err := storage.MischiefTiers()
	if err != nil {
		slog.Error("mischief: catalog", "err", err)
		writeMischiefError(w, http.StatusInternalServerError, "internal error")
		return
	}
	if tiers == nil {
		tiers = []storage.MischiefTier{}
	}
	resp := mischiefCatalogResp{Tiers: tiers}
	if lp := buyerLocalpart(u); lp != "" {
		euro, has, err := storage.UserEuro(lp)
		if err != nil {
			slog.Error("mischief: balance", "err", err)
		} else {
			resp.Euro, resp.HasBalance = euro, has
		}
	}
	w.Header().Set("Cache-Control", "no-store")
	writeJSON(w, resp)
}

// ---- the gogobee wire: bearer-authed, idempotent -------------------------------

// handleMischiefPending is gogobee's poll: every order still waiting to be acted
// on. A pending order carries no intermediate state, so unlike escrow there is no
// stale-reoffer window — a gogobee that dies mid-claim simply leaves the order
// pending to be offered again, and the guid makes the replay a no-op.
func (s *Server) handleMischiefPending(w http.ResponseWriter, r *http.Request) {
	if !s.bearerOK(r) {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}
	orders, err := storage.PendingMischiefOrders(mischiefPollLimit)
	if err != nil {
		slog.Error("mischief: pending", "err", err)
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}
	if orders == nil {
		orders = []storage.MischiefOrder{}
	}
	writeJSON(w, orders)
}

// mischiefPollLimit caps one poll, matching the escrow seam.
const mischiefPollLimit = 50

// mischiefVerdict is gogobee's answer on a claimed order: the terminal status and
// a human note to render.
type mischiefVerdict struct {
	GUID   string `json:"guid"`
	Status string `json:"status"`
	Detail string `json:"detail,omitempty"`
}

// handleMischiefClaim files gogobee's verdict against a pending order. Idempotent:
// gogobee's poll loop retries, so the same verdict can arrive more than once and
// only the first one moves the order. An unknown guid is a 400 — by this point
// gogobee has already debited the buyer for an order Pete has no record of, and
// under the seam's contract a 400 parks the row for a human rather than retrying
// forever against a row that will never exist.
func (s *Server) handleMischiefClaim(w http.ResponseWriter, r *http.Request) {
	if !s.bearerOK(r) {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}
	var v mischiefVerdict
	if err := json.NewDecoder(io.LimitReader(r.Body, 1<<14)).Decode(&v); err != nil {
		http.Error(w, "bad json", http.StatusBadRequest)
		return
	}
	if v.GUID == "" {
		http.Error(w, "guid is required", http.StatusBadRequest)
		return
	}

	order, err := storage.ResolveMischiefOrder(v.GUID, v.Status, v.Detail)
	if errors.Is(err, storage.ErrNoSuchOrder) {
		slog.Error("mischief: verdict for an order we have never heard of — "+
			"gogobee may have debited a buyer for it", "guid", v.GUID, "status", v.Status)
		http.Error(w, "no such order", http.StatusBadRequest)
		return
	}
	if err != nil {
		// A malformed verdict status lands here — also a contract mismatch, so 400.
		slog.Error("mischief: resolve", "guid", v.GUID, "status", v.Status, "err", err)
		http.Error(w, "bad verdict", http.StatusBadRequest)
		return
	}
	slog.Info("mischief: order resolved", "guid", order.GUID, "status", order.Status)
	writeJSON(w, order)
}

func writeMischiefError(w http.ResponseWriter, code int, msg string) {
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
	w.WriteHeader(code)
	_ = json.NewEncoder(w).Encode(map[string]string{"error": msg})
}