package web

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

	"pete/internal/storage"
)

// The action queue's web seam — the first verbs the web can play, as opposed to
// the equip queue's dressing-up.
//
// Two audiences, same shape as equip and mischief. A signed-in owner clicks
// "Pull out" on their own adventurer page or "Take your bout" on the war room;
// gogobee hits the bearer-authed pair, polling pending orders and pushing a
// verdict. Pete runs no game rule: it records that somebody asked, and renders
// what gogobee answered. The UI says "asked for" and never claims it landed.
//
// The character is resolved from the SESSION, never from the request. A session
// maps to exactly one localpart and a localpart to exactly one adventurer, so
// there is nothing for the client to name and therefore nothing to forge — the
// equip queue has to take an item id and a slot off the wire and re-resolve them;
// this one has no such surface at all.

// advOrderBurstWindow / advOrderBurstMax blunt a stuck mouse button. The real
// gates are gogobee's — one extraction ends the run, one bout per day — and the
// pending-order guard below stops the common double-click outright.
const (
	advOrderBurstWindow = time.Hour
	advOrderBurstMax    = 30
)

// advOrderReq is the browser's request: the verb, and for the three verbs that
// take arguments, which zone / which loadout / how many days. See the file
// comment on why nothing here identifies the character.
//
// None of these fields is trusted. Each is looked up in the owner's OWN offer
// list — the one gogobee pushed onto their private self-detail row — and the
// order stores what was found there, not what was sent. So a forged zone id
// resolves to nothing and is refused before an order exists.
type advOrderReq struct {
	Action  string `json:"action"`
	Zone    string `json:"zone,omitempty"`
	Loadout string `json:"loadout,omitempty"`
	Days    int    `json:"days,omitempty"`
}

// handleAdvOrder places a pending action for the signed-in owner. It asserts what
// Pete can honestly know — the viewer is signed in, and gogobee has pushed a
// self-detail row for them, which is gogobee's own proof that this person has an
// adventurer. Everything about whether the action is legal *right now* is
// gogobee's, at verdict time; the pre-checks here only produce a better message
// than a verdict thirty seconds later would.
func (s *Server) handleAdvOrder(w http.ResponseWriter, r *http.Request) {
	u := s.requireUser(w, r)
	if u == nil {
		return
	}
	owner := buyerLocalpart(u)
	if owner == "" {
		writeAdvOrderError(w, http.StatusConflict, "please sign in again")
		return
	}

	var req advOrderReq
	if !decodeStateBody(w, r, &req) {
		return
	}
	switch req.Action {
	case storage.AdvActionExtract, storage.AdvActionSiegeJoin,
		storage.AdvActionExpedition, storage.AdvActionResume, storage.AdvActionBabysit,
		storage.AdvActionAbandon, storage.AdvActionLeave, storage.AdvActionBabysitCancel:
	default:
		writeAdvOrderError(w, http.StatusBadRequest, "bad action")
		return
	}

	// Ownership. The self-detail row is gogobee's own owner<->adventurer proof, the
	// same join the who page's private panels and the alert sender use. No row means
	// this account has no adventurer — or gogobee has stopped pushing, in which case
	// an order it can't attribute is not one we should queue.
	token, ok := storage.SelfToken(owner)
	if !ok {
		writeAdvOrderError(w, http.StatusForbidden, "no adventurer on the board for this account")
		return
	}

	// One outstanding order per verb. Two queued extracts would apply in sequence
	// and the second would answer "no expedition to leave" — a rejection for
	// something that worked, which is the worst thing this strip could say.
	if pending, err := storage.HasPendingAdvOrder(u.Sub, req.Action); err != nil {
		slog.Error("orders: pending lookup", "err", err)
		writeAdvOrderError(w, http.StatusInternalServerError, "internal error")
		return
	} else if pending {
		writeAdvOrderError(w, http.StatusConflict, "already asked — waiting on the game box")
		return
	}

	since := time.Now().Add(-advOrderBurstWindow).Unix()
	if n, err := storage.CountAdvOrdersSince(u.Sub, since); err != nil {
		slog.Error("orders: burst count", "err", err)
		writeAdvOrderError(w, http.StatusInternalServerError, "internal error")
		return
	} else if n >= advOrderBurstMax {
		writeAdvOrderError(w, http.StatusTooManyRequests, "slow down, too many requests in a short while")
		return
	}

	// Per-verb pre-checks, all courtesy only. Both read Pete's snapshot copy, which
	// is up to two minutes behind the game box, so neither is authoritative and
	// neither is allowed to be the last word — a run that ended in that window comes
	// back from gogobee as rejected_not_running, which is the honest answer.
	characterName := ""
	entry, haveEntry, err := storage.RosterEntryByToken(token)
	if err != nil {
		slog.Error("orders: roster lookup", "err", err)
		writeAdvOrderError(w, http.StatusInternalServerError, "internal error")
		return
	}
	if haveEntry {
		characterName = entry.Name
	}
	switch req.Action {
	case storage.AdvActionExtract:
		if haveEntry && entry.Status != "expedition" {
			writeAdvOrderError(w, http.StatusConflict, "you're not on an expedition")
			return
		}
	case storage.AdvActionSiegeJoin:
		snap, known, err := storage.LoadSiege()
		if err != nil {
			slog.Error("orders: siege lookup", "err", err)
			writeAdvOrderError(w, http.StatusInternalServerError, "internal error")
			return
		}
		if known && !snap.Active {
			writeAdvOrderError(w, http.StatusConflict, "no Siege is camped outside town")
			return
		}
	}

	// Resolve the verb's arguments against this owner's own offers. Everything
	// this returns came out of gogobee's push, so the stored order can only ever
	// name a zone, a loadout and a price the game itself quoted to this player.
	params, msg := resolveAdvOrderParams(owner, token, req)
	if msg != "" {
		writeAdvOrderError(w, http.StatusConflict, msg)
		return
	}

	order, err := storage.InsertAdvOrder(u.Sub, owner, token, characterName, req.Action, params)
	if err != nil {
		slog.Error("orders: insert order", "err", err)
		writeAdvOrderError(w, http.StatusInternalServerError, "internal error")
		return
	}
	slog.Info("orders: action placed", "guid", order.GUID, "owner", owner, "action", req.Action)
	w.Header().Set("Cache-Control", "no-store")
	writeJSON(w, order)
}

// resolveAdvOrderParams turns the browser's arguments into the stored ones by
// looking each up in the owner's pushed offer list, and returns the reason to
// refuse when it cannot. Five of the eight verbs take no arguments and resolve to
// nil — but babysit_cancel still comes through here, because the offer row is
// the one place Pete can see that there is no sitter to dismiss.
//
// Note what W5a's "Pete has never heard about it" asymmetry does NOT need to
// become here. There is no such state to defer on: the detail row this reads is
// the same row SelfToken already found, so by the time we get here it exists.
// What a gogobee too old to push offers produces is an EMPTY offer list, and
// then the page renders no picker at all — so there is no dead button to protect
// against, only forged arguments to refuse.
func resolveAdvOrderParams(owner, token string, req advOrderReq) (*storage.AdvOrderParams, string) {
	switch req.Action {
	case storage.AdvActionExtract, storage.AdvActionSiegeJoin:
		return nil, ""
	case storage.AdvActionAbandon, storage.AdvActionLeave:
		// No snapshot pre-check for either, deliberately, and it is the same call
		// W5a made for extract: the board is up to two minutes stale, so the only
		// thing Pete could test — "the mark reads idle" — would refuse actions the
		// game would have allowed. Abandon is worse than extract in that respect,
		// because an *extracted* expedition is still abandonable while its owner
		// reads as standing in town. gogobee answers rejected_not_running /
		// rejected_not_leader / rejected_is_leader, and the strip shows it.
		return nil, ""
	}
	detail, haveDetail, err := storage.PlayerDetailByOwner(owner, token)
	if err != nil {
		slog.Error("orders: detail lookup", "err", err)
		return nil, "couldn't read your adventurer just now"
	}
	if !haveDetail {
		// Only reachable if the row went away between SelfToken and here — the
		// roster push replaces the whole table. Refuse rather than guess.
		return nil, "couldn't read your adventurer just now"
	}

	switch req.Action {
	case storage.AdvActionExpedition:
		if req.Zone == "" {
			return nil, "pick somewhere to go first"
		}
		if len(detail.Zones) == 0 {
			return nil, "you're already out there"
		}
		for _, z := range detail.Zones {
			if z.ID != req.Zone {
				continue
			}
			for _, l := range z.Loadouts {
				if l.Key == req.Loadout {
					return &storage.AdvOrderParams{Zone: z.ID, Loadout: l.Key}, ""
				}
			}
			return nil, "that isn't a loadout for that zone"
		}
		return nil, "that zone isn't open to you"

	case storage.AdvActionResume:
		if detail.Resume == nil {
			return nil, "there's no expedition waiting for you"
		}
		for _, l := range detail.Resume.Loadouts {
			if l.Key == req.Loadout {
				return &storage.AdvOrderParams{Loadout: l.Key}, ""
			}
		}
		return nil, "that isn't a loadout for that zone"

	case storage.AdvActionBabysit:
		if req.Days != 7 && req.Days != 30 {
			return nil, "the sitter works by the week or by the month"
		}
		if detail.Babysit != nil && detail.Babysit.Active {
			return nil, "a sitter is already looking after your camp"
		}
		return &storage.AdvOrderParams{Days: req.Days}, ""

	case storage.AdvActionBabysitCancel:
		// The mirror of the check above, and the one W9 verb where the snapshot
		// really does contradict the request: a sitter's engagement is a fact about
		// the character, not about where they are standing, so it does not go stale
		// the way "on an expedition" does. A missing offer is still not a refusal —
		// that is a gogobee too old to push one, not a player without a sitter.
		if detail.Babysit != nil && !detail.Babysit.Active {
			return nil, "there's no sitter to dismiss"
		}
		return nil, ""
	}
	return nil, "bad action"
}

// handleAdvOrders returns the signed-in owner's own recent actions for the status
// strip, newest first. Scoped to their OIDC subject.
func (s *Server) handleAdvOrders(w http.ResponseWriter, r *http.Request) {
	u := s.requireUser(w, r)
	if u == nil {
		return
	}
	orders, err := storage.AdvOrdersByOwner(u.Sub, 10)
	if err != nil {
		slog.Error("orders: by owner", "err", err)
		writeAdvOrderError(w, http.StatusInternalServerError, "internal error")
		return
	}
	if orders == nil {
		orders = []storage.AdvOrder{}
	}
	w.Header().Set("Cache-Control", "no-store")
	writeJSON(w, orders)
}

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

// advOrderPollLimit caps one poll, matching the equip and mischief seams.
const advOrderPollLimit = 50

// handleAdvOrdersPending is gogobee's poll: every action still waiting. Like the
// seams beside it there is no stale-reoffer window — a gogobee that dies mid-apply
// leaves the order pending to be offered again, and its guid ledger makes the
// replay a no-op.
func (s *Server) handleAdvOrdersPending(w http.ResponseWriter, r *http.Request) {
	if !s.bearerOK(r) {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}
	orders, err := storage.PendingAdvOrders(advOrderPollLimit)
	if err != nil {
		slog.Error("orders: pending", "err", err)
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}
	if orders == nil {
		orders = []storage.AdvOrder{}
	}
	writeJSON(w, orders)
}

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

// handleAdvOrderVerdict 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 moves the order. An unknown guid is a 400 — under
// this seam's contract that parks the row for a human rather than retrying
// forever against a row that will never exist.
func (s *Server) handleAdvOrderVerdict(w http.ResponseWriter, r *http.Request) {
	if !s.bearerOK(r) {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}
	var v advOrderVerdict
	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.ResolveAdvOrder(v.GUID, v.Status, v.Detail)
	if errors.Is(err, storage.ErrNoSuchAdvOrder) {
		slog.Error("orders: verdict for an order we've never heard of", "guid", v.GUID, "status", v.Status)
		http.Error(w, "no such order", http.StatusBadRequest)
		return
	}
	if errors.Is(err, storage.ErrBadAdvVerdict) {
		slog.Error("orders: verdict outside the terminal set", "guid", v.GUID, "status", v.Status)
		http.Error(w, "bad verdict", http.StatusBadRequest)
		return
	}
	if err != nil {
		// A storage failure, not a bad request. 400 here would park a perfectly
		// resolvable order forever on a transient database error; 500 gets it
		// retried on gogobee's next poll.
		slog.Error("orders: resolve", "guid", v.GUID, "status", v.Status, "err", err)
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}
	slog.Info("orders: action resolved", "guid", order.GUID, "action", order.Action, "status", order.Status)
	writeJSON(w, order)
}

func writeAdvOrderError(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})
}