package storage

import (
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
)

// The action queue: the second channel that carries intent back to the game box,
// and the first one that acts on the adventurer rather than on their kit.
//
// Same shape as the equip queue, deliberately — a signed-in owner asks for
// something on a page they own, Pete records only the intent, gogobee polls,
// runs the real rule against its own tables, and files a verdict Pete renders.
// Pete never ends an expedition and never swings at a boss; it records that
// somebody asked to.
//
// The reason this is its own table rather than more actions on equip_orders is
// vocabulary: an equip order is about an item in a slot at a tier, and none of
// those columns mean anything to "leave the dungeon". See the schema comment.
//
// Neither verb is naturally idempotent — an extract ends a run, a bout spends
// the day's only swing — so gogobee guards on the order guid before it mutates,
// exactly as the equip poller does. On Pete's side the mechanic is the equip
// queue's: a verdict only moves a still-pending row, so a retried verdict is a
// no-op.

// AdvOrder is one requested action and its current standing.
type AdvOrder struct {
	GUID           string `json:"guid"`
	OwnerSub       string `json:"-"`                        // OIDC subject; keys "my orders", never sent to gogobee
	OwnerLocalpart string `json:"owner_localpart"`          // Matrix localpart gogobee turns into an MXID — whose adventurer acts
	Token          string `json:"token,omitempty"`          // the roster token ownership was proven against; display/audit only
	CharacterName  string `json:"character_name,omitempty"` // display copy, frozen at order time; gogobee ignores it
	Action         string `json:"action"`
	Status         string `json:"status"`
	Detail         string `json:"detail,omitempty"`
	CreatedAt      int64  `json:"created_at"`
	UpdatedAt      int64  `json:"updated_at,omitempty"`
	// Params is the verb's arguments, and only the three verbs that take any carry
	// it. It never names an adventurer — that still comes from the session — and
	// nothing in it is trusted: Pete resolves every field against the owner's own
	// pushed offer list before storing it, and gogobee resolves it again against
	// the game's tables before it means anything.
	Params *AdvOrderParams `json:"params,omitempty"`
}

// AdvOrderParams is the union of every verb's arguments, flat rather than
// per-verb because there are three of them and each reads one or two fields.
// A field a verb does not read is ignored rather than rejected.
type AdvOrderParams struct {
	Zone    string `json:"zone,omitempty"`    // zone id, for expedition_start
	Loadout string `json:"loadout,omitempty"` // lean|balanced|heavy
	Days    int    `json:"days,omitempty"`    // 7 or 30, for babysit
}

// Actions. These cross the wire to gogobee, so they are part of the contract.
//
// extract   pull out of a running expedition, keeping loot/XP, resumable for a
//           week — the game's `!extract`. Leader-only, which gogobee enforces.
// siege_join take today's one bout against the world boss — `!adventure
//           worldboss fight`. The narration still lands in Matrix; the web gets
//           the damage line as the verdict.
// W5b adds the three that take arguments and spend coins:
//
// expedition_start   leave town for a zone with a supply loadout — `!expedition
//                    start <zone> <loadout>`. The most common action in the game
//                    and, until now, Matrix-only.
// expedition_resume  walk back into the run you extracted from, re-outfitted —
//                    `!resume`. The other half of W5a's extract: that verb's own
//                    verdict tells people to type !resume, and this is the door.
// babysit            engage the pet sitter for a week or a month — `!adventure
//                    babysit week|month`.
//
// W9 adds the three that undo the ones above. Each was already named inside a
// refusal or a confirm this page shows — "`!expedition abandon` first",
// "`!expedition leave` to walk out alone", "no refund if you cancel early" — so
// until now the web told people to go and type a command it could have offered.
// None takes an argument and none spends a euro:
//
// expedition_abandon end the expedition outright, for the whole party. Leader
//                    only, which gogobee enforces. Also the way to close an
//                    extracted run without paying to walk back into it first.
// expedition_leave   walk out of somebody else's party alone, supplies left in
//                    the pool. Member only — the leader's row IS the expedition.
// babysit_cancel     dismiss the sitter early. No refund, by the game's design.
const (
	AdvActionExtract    = "extract"
	AdvActionSiegeJoin  = "siege_join"
	AdvActionExpedition = "expedition_start"
	AdvActionResume     = "expedition_resume"
	AdvActionBabysit    = "babysit"

	AdvActionAbandon       = "expedition_abandon"
	AdvActionLeave         = "expedition_leave"
	AdvActionBabysitCancel = "babysit_cancel"
)

// Order states. Terminal states are enumerated rather than free-text so the page
// can say something specific about each; detail carries gogobee's prose. The
// rejection set is honest to what the game paths can actually answer.
const (
	AdvOrderPending = "pending" // placed; gogobee hasn't acted yet
	AdvOrderApplied = "applied" // it happened; detail says what

	AdvRejectedNotRunning    = "rejected_not_running"    // extract: no active expedition
	AdvRejectedNotLeader     = "rejected_not_leader"     // extract: a party member can't call the extraction
	AdvRejectedNoSiege       = "rejected_no_siege"       // siege_join: nothing camped outside town
	AdvRejectedAlreadyFought = "rejected_already_fought" // siege_join: today's bout is spent
	AdvRejectedUnavailable   = "rejected_unavailable"    // no character, dead, or an argument the game does not sell

	// W5b's three verbs.
	AdvRejectedBusy              = "rejected_busy"               // already out, already seated, or already has a sitter
	AdvRejectedInsufficientFunds = "rejected_insufficient_funds" // could not cover the cost
	AdvRejectedZoneLocked        = "rejected_zone_locked"        // that zone is not open at this level
	AdvRejectedNothingToResume   = "rejected_nothing_to_resume"  // nothing extracted, or its window closed

	// W9's two. rejected_is_leader is deliberately not rejected_not_leader read
	// backwards: they are opposite facts about the same person, and collapsing
	// them would answer a leader who tried to walk out by telling them they are
	// not the leader.
	AdvRejectedIsLeader        = "rejected_is_leader"         // expedition_leave: the leader's row is the expedition
	AdvRejectedNothingToCancel = "rejected_nothing_to_cancel" // babysit_cancel: no sitter is engaged
)

func validAdvAction(action string) bool {
	switch action {
	case AdvActionExtract, AdvActionSiegeJoin,
		AdvActionExpedition, AdvActionResume, AdvActionBabysit,
		AdvActionAbandon, AdvActionLeave, AdvActionBabysitCancel:
		return true
	}
	return false
}

// validAdvVerdict is the set of terminal states gogobee may hand back.
func validAdvVerdict(status string) bool {
	switch status {
	case AdvOrderApplied, AdvRejectedNotRunning, AdvRejectedNotLeader,
		AdvRejectedNoSiege, AdvRejectedAlreadyFought, AdvRejectedUnavailable,
		AdvRejectedBusy, AdvRejectedInsufficientFunds, AdvRejectedZoneLocked,
		AdvRejectedNothingToResume, AdvRejectedIsLeader, AdvRejectedNothingToCancel:
		return true
	}
	return false
}

var ErrNoSuchAdvOrder = errors.New("orders: no such order")

// InsertAdvOrder records a fresh, pending order and returns it with a new guid.
// The guid is minted here so the owner has a stable reference the instant they
// click, before gogobee has heard of it. The caller has already proved the signed-
// in viewer owns this adventurer; whether the action is *legal right now* is
// gogobee's answer, at verdict time.
func InsertAdvOrder(ownerSub, ownerLocalpart, token, characterName, action string, params *AdvOrderParams) (AdvOrder, error) {
	if !validAdvAction(action) {
		return AdvOrder{}, fmt.Errorf("orders: bad action %q", action)
	}
	// Store the canonical re-serialised form, never the client's bytes: the caller
	// has already resolved every field against the owner's own offer list, so what
	// goes in the row is Pete's understanding of the request rather than the
	// request itself.
	paramsJSON := ""
	if params != nil {
		b, err := json.Marshal(params)
		if err != nil {
			return AdvOrder{}, fmt.Errorf("orders: marshal params: %w", err)
		}
		paramsJSON = string(b)
	}
	guid, err := newGUID()
	if err != nil {
		return AdvOrder{}, err
	}
	now := nowUnix()
	if _, err := Get().Exec(
		`INSERT INTO adventure_orders
		    (guid, owner_sub, owner_localpart, token, character_name, action, status, params, created_at, updated_at)
		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
		guid, ownerSub, ownerLocalpart, token, characterName, action, AdvOrderPending, paramsJSON, now, now,
	); err != nil {
		return AdvOrder{}, fmt.Errorf("orders: insert order: %w", err)
	}
	return AdvOrder{
		GUID: guid, OwnerSub: ownerSub, OwnerLocalpart: ownerLocalpart,
		Token: token, CharacterName: characterName, Action: action,
		Status: AdvOrderPending, Params: params, CreatedAt: now, UpdatedAt: now,
	}, nil
}

// PendingAdvOrders is gogobee's poll: every order still waiting. Like the equip
// queue there is no claimed-but-stale window — a gogobee that dies mid-apply
// leaves the order pending to be offered again, and its own guid ledger makes the
// replay a no-op.
func PendingAdvOrders(limit int) ([]AdvOrder, error) {
	if limit <= 0 {
		limit = 100
	}
	rows, err := Get().Query(
		`SELECT guid, owner_sub, owner_localpart, token, character_name, action, status, COALESCE(detail, ''), COALESCE(params, ''), created_at, updated_at
		   FROM adventure_orders
		  WHERE status = ?
		  ORDER BY created_at
		  LIMIT ?`,
		AdvOrderPending, limit,
	)
	if err != nil {
		return nil, fmt.Errorf("orders: pending orders: %w", err)
	}
	defer rows.Close()
	return scanAdvOrders(rows)
}

// ResolveAdvOrder files gogobee's verdict against a pending order. Idempotent by
// the equip queue's mechanic: the UPDATE only moves a still-pending row, and the
// row is read back unconditionally so a first verdict, a retried verdict, and a
// missing row all take one path.
func ResolveAdvOrder(guid, status, detail string) (AdvOrder, error) {
	if !validAdvVerdict(status) {
		return AdvOrder{}, fmt.Errorf("orders: bad verdict %q", status)
	}
	now := nowUnix()
	if _, err := Get().Exec(
		`UPDATE adventure_orders SET status = ?, detail = ?, updated_at = ?
		  WHERE guid = ? AND status = ?`,
		status, detail, now, guid, AdvOrderPending,
	); err != nil {
		return AdvOrder{}, fmt.Errorf("orders: resolve order: %w", err)
	}
	return AdvOrderByGUID(guid)
}

// AdvOrderByGUID reads one order.
func AdvOrderByGUID(guid string) (AdvOrder, error) {
	rows, err := Get().Query(
		`SELECT guid, owner_sub, owner_localpart, token, character_name, action, status, COALESCE(detail, ''), COALESCE(params, ''), created_at, updated_at
		   FROM adventure_orders WHERE guid = ?`, guid,
	)
	if err != nil {
		return AdvOrder{}, fmt.Errorf("orders: read order: %w", err)
	}
	defer rows.Close()
	out, err := scanAdvOrders(rows)
	if err != nil {
		return AdvOrder{}, err
	}
	if len(out) == 0 {
		return AdvOrder{}, ErrNoSuchAdvOrder
	}
	return out[0], nil
}

// AdvOrdersByOwner returns an owner's own recent orders, newest first, for the
// status strip. Keyed on the OIDC subject so a rename doesn't strand history.
func AdvOrdersByOwner(ownerSub string, limit int) ([]AdvOrder, error) {
	if limit <= 0 {
		limit = 20
	}
	rows, err := Get().Query(
		`SELECT guid, owner_sub, owner_localpart, token, character_name, action, status, COALESCE(detail, ''), COALESCE(params, ''), created_at, updated_at
		   FROM adventure_orders
		  WHERE owner_sub = ?
		  ORDER BY created_at DESC
		  LIMIT ?`,
		ownerSub, limit,
	)
	if err != nil {
		return nil, fmt.Errorf("orders: orders by owner: %w", err)
	}
	defer rows.Close()
	return scanAdvOrders(rows)
}

// HasPendingAdvOrder reports whether this owner already has an unanswered order
// of this action outstanding. Unlike the equip queue's burst counter this is a
// correctness guard, not anti-spam: two queued extracts would apply in sequence
// and the second would come back "no expedition to leave", which reads as a
// failure for something that in fact worked.
func HasPendingAdvOrder(ownerSub, action string) (bool, error) {
	var n int
	err := Get().QueryRow(
		`SELECT COUNT(*) FROM adventure_orders WHERE owner_sub = ? AND action = ? AND status = ?`,
		ownerSub, action, AdvOrderPending,
	).Scan(&n)
	if err != nil {
		return false, fmt.Errorf("orders: pending lookup: %w", err)
	}
	return n > 0, nil
}

// CountAdvOrdersSince backs the web anti-spam guard, same role as the equip
// queue's: the real eligibility is gogobee's at verdict time, this only blunts a
// stuck mouse button.
func CountAdvOrdersSince(ownerSub string, since int64) (int, error) {
	var n int
	err := Get().QueryRow(
		`SELECT COUNT(*) FROM adventure_orders WHERE owner_sub = ? AND created_at >= ?`,
		ownerSub, since,
	).Scan(&n)
	if err != nil {
		return 0, fmt.Errorf("orders: count recent orders: %w", err)
	}
	return n, nil
}

func scanAdvOrders(rows *sql.Rows) ([]AdvOrder, error) {
	var out []AdvOrder
	for rows.Next() {
		var o AdvOrder
		var params string
		if err := rows.Scan(&o.GUID, &o.OwnerSub, &o.OwnerLocalpart, &o.Token,
			&o.CharacterName, &o.Action, &o.Status, &o.Detail, &params,
			&o.CreatedAt, &o.UpdatedAt); err != nil {
			return nil, fmt.Errorf("orders: scan order: %w", err)
		}
		// Unparseable params are dropped rather than failing the read. The row is
		// still a real order somebody placed, and a verb whose arguments went
		// missing is refused honestly by gogobee ("that order didn't say where
		// to") — which beats the whole poll erroring on one bad row.
		if params != "" {
			var pp AdvOrderParams
			if err := json.Unmarshal([]byte(params), &pp); err == nil {
				o.Params = &pp
			}
		}
		out = append(out, o)
	}
	return out, rows.Err()
}