package main

import (
	"fmt"
	"net/http"
	"slices"
	"strings"
	"time"
	"unicode/utf8"
)

var crowPostable = map[string]bool{
	"say":     true,
	"request": true,
	"claim":   true,
	"deliver": true,
	"refer":   true,
	"decline": true,
}

// nestReplySystem tells an addressed crow the response contract: its reply
// must open with a KIND line the harness reads (must-respond).
const markerNestReply = "This is a chatroom request."
const nestReplySystem = crowSystem + `
` + markerNestReply + ` Start your reply on its own first line with exactly:
KIND: claim   (you will do it)
KIND: deliver (here is the result)
KIND: decline (with a reason)
Then, on the next line, your message text.`

// nestMembers lists who may be addressed in a nest: its crows plus the owner.
func nestMembers(nest Nest) []string {
	return append(append([]string{}, nest.Crows...), "owner")
}

func (s *Server) getNestMessages(w http.ResponseWriter, r *http.Request) {
	nestID := r.PathValue("nest_id")
	if _, found := s.nests.Get(nestID); !found {
		httpError(w, http.StatusNotFound, fmt.Sprintf("There is no nest called %q.", nestID))
		return
	}
	all := s.msgs.All(nestID)
	out := make([]map[string]any, 0, len(all))
	for _, m := range all {
		out = append(out, nestRecord(m))
	}
	writeJSON(w, http.StatusOK, out)
}

// nestRecord is the EVENTS.md wire shape for one message.
func nestRecord(m Message) map[string]any {
	rec := map[string]any{
		"msg_id":    m.MsgID(),
		"kind":      m.Kind,
		"author":    m.Author,
		"text":      m.Text,
		"to":        m.To,
		"refers_to": m.RefersTo,
		"tagged_by": m.TaggedBy,
		"ts":        m.Timestamp,
	}
	if m.Mode != "" {
		rec["mode"] = m.Mode
		rec["mode_tagged_by"] = m.ModeTagged
	}
	if m.Invited > 0 {
		rec["invited"] = m.Invited
	}
	return rec
}

func (s *Server) postNestMessage(w http.ResponseWriter, r *http.Request) {
	nestID := r.PathValue("nest_id")
	nest, found := s.nests.Get(nestID)
	if !found {
		httpError(w, http.StatusNotFound, fmt.Sprintf("There is no nest called %q.", nestID))
		return
	}

	var body struct {
		Author   string `json:"author"`
		Text     string `json:"text"`
		Kind     string `json:"kind"`
		Mode     string `json:"mode"`
		Invited  int    `json:"invited"`
		To       string `json:"to"`
		RefersTo string `json:"refers_to"`
	}
	if !decode(w, r, &body) {
		return
	}

	body.Text = strings.TrimSpace(body.Text)
	body.To = strings.TrimSpace(body.To)
	if body.To == "" {
		body.To = parseAddressing(body.Text, nestMembers(nest))
	}

	// Guardrails (EVENTS.md: Nest messages → Guardrails)
	if n := utf8.RuneCountInString(body.Text); n < 1 || n > s.p.G.MaxItemChars {
		httpError(w, http.StatusBadRequest, fmt.Sprintf("A message is 1 to %d characters.", s.p.G.MaxItemChars))
		return
	}
	if body.Author == "owner" {
		// owner can always post
	} else if !slices.Contains(nest.Crows, body.Author) {
		httpError(w, http.StatusBadRequest, fmt.Sprintf("%q is not a member of %s.", body.Author, nestID))
		return
	}
	if body.Author != "owner" {
		if ok, msg, wait := s.p.Ledger.Admit(body.Author, time.Now(), s.p.G); !ok {
			cooldown := int(wait.Seconds())
			writeJSON(w, http.StatusTooManyRequests, map[string]any{"message": msg, "cooldown_s": cooldown})
			return
		}
	}
	if body.Kind != "" && body.Author != "owner" && !crowPostable[body.Kind] {
		httpError(w, http.StatusBadRequest, fmt.Sprintf("%q is not a kind crows may post.", body.Kind))
		return
	}

	// Tagging (A1, EVENTS.md): Jev first, header fallback, say as last resort.
	kind, taggedBy := s.tagKind(body.Kind, body.Text)

	// claim/deliver/decline answer a request: with no explicit address they go
	// back to whoever posted the message they refer to (EVENTS.md deliver rule).
	if body.To == "" && (kind == "claim" || kind == "deliver" || kind == "decline") && body.RefersTo != "" {
		if origin, found := s.msgs.ByMsgID(body.RefersTo); found {
			body.To = origin.Author
		}
	}

	// Mode (Epic C, same rule shape as kind): Jev first, header escape, "" when unsure.
	mode, modeBy := s.tagMode(kind, body.Mode, body.Text)

	// A conspiracy expects several crows on the one task; the invite count is
	// capped by MurderSize and the flock's in-flight limit.
	invited := 0
	if mode == "conspiracy" {
		invited = s.inviteCount(nest, body.Invited)
	}

	// Claim arbitration (#5, Epic C): first claim wins unless the referent is a
	// conspiracy, which expects multiple claims.
	if kind == "claim" && body.RefersTo != "" {
		if origin, found := s.msgs.ByMsgID(body.RefersTo); found && origin.Mode != "conspiracy" {
			if owner, claimed := s.msgs.FirstClaim(origin.NestID, origin.MsgID()); claimed {
				httpError(w, http.StatusConflict, origin.MsgID()+" is claimed by "+owner+"; review it instead of redoing it.")
				return
			}
		}
	}

	msg := Message{
		NestID:     nestID,
		Kind:       kind,
		Author:     body.Author,
		Text:       body.Text,
		To:         body.To,
		RefersTo:   body.RefersTo,
		TaggedBy:   taggedBy,
		Mode:       mode,
		ModeTagged: modeBy,
		Invited:    invited,
		Timestamp:  time.Now().UTC().Format(time.RFC3339),
	}
	record, err := s.msgs.Append(msg)
	if err != nil {
		httpError(w, http.StatusInternalServerError, "could not save the message: "+err.Error())
		return
	}

	s.emitNestMessage(record)

	// Event-driven trigger (no idle loops):
	//   conspiracy -> several invited crows, each from its own lens
	//   any other request addressed to a member crow -> one must-respond reply
	if kind == "request" {
		switch {
		case mode == "conspiracy" && invited > 0:
			go s.respondConspiracy(nest, record, invited)
		case slices.Contains(nest.Crows, record.To):
			go s.respondToRequest(nest, record)
		}
	}

	writeJSON(w, http.StatusCreated, nestRecord(record))
}

var modePostable = map[string]bool{"solo": true, "conspiracy": true, "split": true}

// tagMode classifies a request's mode (Jev first, header escape). Only requests
// carry a mode; other kinds get "".
func (s *Server) tagMode(kind, header, text string) (string, string) {
	if kind != "request" {
		return "", ""
	}
	if m, ok := s.p.Flock.ClassifyMode(s.ctx, text); ok {
		if modePostable[header] && header != m {
			return m, "disagreement"
		}
		return m, "jev"
	}
	if modePostable[header] {
		return header, "header"
	}
	return "", "default"
}

// tagKind runs the A1 rule: Jev first; Jev unsure -> the poster's header;
// neither -> say. tagged_by records which source won, and a Jev override of a
// header logs as a disagreement (fuel for calibration).
func (s *Server) tagKind(header, text string) (string, string) {
	kind, _, ok := s.p.Flock.ClassifyKind(s.ctx, text)
	if ok {
		if crowPostable[header] && header != kind {
			return kind, "disagreement"
		}
		return kind, "jev"
	}
	if crowPostable[header] {
		return header, "header"
	}
	return "say", "default"
}

func (s *Server) emitNestMessage(m Message) {
	rec := nestRecord(m)
	rec["nest_id"] = m.NestID
	s.hub.PublishNest(m.NestID, "nest.message", rec)
}

// inviteCount is how many crows a conspiracy asks to take the one task, capped
// by MurderSize, the flock's in-flight limit, and the nest's own size.
func (s *Server) inviteCount(nest Nest, requested int) int {
	cap := s.p.G.MurderSize
	if s.p.G.MaxCrowsInFlight < cap {
		cap = s.p.G.MaxCrowsInFlight
	}
	if requested > 0 && requested < cap {
		cap = requested
	}
	if len(nest.Crows) < cap {
		cap = len(nest.Crows)
	}
	return cap
}

// respondConspiracy invites N crows; each answers from its own persona lens so
// distinct strengths produce distinct readings.
func (s *Server) respondConspiracy(nest Nest, req Message, invited int) {
	crows := s.p.Flock.pick(nest, invited)
	for _, crow := range crows {
		go s.respondOne(nest, req, crow, true)
	}
}

// conspiracyLine is the lens directive added to every invited crow's prompt.
const conspiracyLine = "You are one lens among several on this request; answer from your own strength, not the flock's consensus."

func (s *Server) respondToRequest(nest Nest, req Message) {
	s.respondOne(nest, req, req.To, false)
}

// respondOne is the must-respond rule for a single crow: answer with claim,
// deliver or decline. A non-responsive reply is retried once with a stricter
// ask; still nothing responsive and the crow gets a Sentry flag (no reply).
func (s *Server) respondOne(nest Nest, req Message, crow string, lens bool) {
	budget := &Budget{name: "nest-reply", limit: s.p.G.TokenBudgetPerItem}
	system := systemFor(crow, nestReplySystem, false)
	prompt := "NEST: " + nest.Name + "\nREQUEST FROM: " + req.Author + "\nRespond to " + req.Author + ".\nTASK: " + req.Text
	if lens {
		strength := ""
		if p, ok := personaOf(crow); ok {
			strength = p.Strength
		}
		prompt += "\n" + conspiracyLine + "\nYour strength: " + strength + " (" + crow + ")."
	}

	kind, body, ok := s.nestReply(system, prompt, crow, budget)
	if !ok {
		nudge := prompt + "\nYour last reply did not claim, deliver or decline this request. Answer with a KIND line now."
		kind, body, ok = s.nestReply(system, nudge, crow, budget)
	}
	if !ok {
		s.postFlag(nest, crow, req)
		return
	}
	reply := Message{
		NestID:    nest.ID,
		Kind:      kind,
		Author:    crow,
		Text:      body,
		To:        req.Author, // responses go back to whoever requested
		RefersTo:  req.MsgID(),
		TaggedBy:  "header",
		Timestamp: time.Now().UTC().Format(time.RFC3339),
	}
	if record, err := s.msgs.Append(reply); err == nil {
		s.emitNestMessage(record)
	}
}

// nestReply asks one crow once and reads its KIND header. ok means the reply
// was responsive (claim, deliver or decline).
func (s *Server) nestReply(system, prompt, crow string, budget *Budget) (kind, body string, ok bool) {
	answer, err := s.p.Flock.ask(s.ctx, nil, crow, system, prompt, budget)
	if err != nil {
		return "", "", false
	}
	kind, body = splitKind(answer)
	if !responsiveKind[kind] || strings.TrimSpace(body) == "" {
		return "", "", false
	}
	return kind, strings.TrimSpace(body), true
}

// postFlag records the Sentry's breach note: an addressed crow that would not
// answer. The quarantine/ask_owner loop lands with the watchdog epic.
func (s *Server) postFlag(nest Nest, crow string, req Message) {
	flag := Message{
		NestID:    nest.ID,
		Kind:      "flag",
		Author:    "Sentry",
		Text:      fmt.Sprintf("%s ignored a request from %s and did not answer after one retry. Flagged for contract breach.", crow, req.Author),
		To:        crow,
		RefersTo:  req.MsgID(),
		TaggedBy:  "harness",
		Timestamp: time.Now().UTC().Format(time.RFC3339),
	}
	if record, err := s.msgs.Append(flag); err == nil {
		s.emitNestMessage(record)
	}
}