package main

import (
	"encoding/json"
	"fmt"
	"slices"
	"strings"
	"time"
)

const quillSystem = `You are Quill crow, the owner's assistant and point of contact in a nest of AI crows.
Answer the owner in one or two plain sentences. You are text-only: no web, no files, no tools.
If the owner's message asks ANOTHER named member crow to do work, your entire reply must begin with the literal first line
RELAY {"crow":"<name>","task":"<text>"}
and contain nothing else. Otherwise answer normally and never start your reply with RELAY.`

// relayPrefix marks a structured relay inside Quill's one reply (D3, #40):
// the same Flock.ask call decides the relay and its payload.
const relayPrefix = "RELAY "

const quillHistoryCap = 20

// quillHistory builds a block of the most recent nest messages (excluding the
// requesting message), formatted as "[author|kind] text" with text truncated
// to 200 runes. Returns a single line when no earlier messages exist.
func quillHistory(all []Message, excludeID int) string {
	var filtered []Message
	for _, m := range all {
		if m.ID != excludeID {
			filtered = append(filtered, m)
		}
	}
	if len(filtered) == 0 {
		return "The nest has no earlier messages."
	}
	if len(filtered) > quillHistoryCap {
		filtered = filtered[len(filtered)-quillHistoryCap:]
	}
	var sb strings.Builder
	for _, m := range filtered {
		text := []rune(m.Text)
		if len(text) > 200 {
			text = text[:200]
		}
		sb.WriteString(fmt.Sprintf("[%s|%s] %s\n", m.Author, m.Kind, string(text)))
	}
	return strings.TrimRight(sb.String(), "\n")
}

// respondQuill answers a message addressed to Quill, the assistant service
// role (CHATROOM_SPEC section 6). D2: reads the nest for status before
// composing its reply. D3 (#40): a reply opening with the RELAY line becomes
// a nest request from Quill to the named member crow instead.
func (s *Server) respondQuill(nest Nest, req Message) {
	budget := &Budget{name: "quill-reply", limit: s.p.G.TokenBudgetPerItem}
	system := systemFor("Quill", quillSystem, false)
	history := quillHistory(s.msgs.All(nest.ID), req.ID)
	prompt := history + "\n---\nFROM: " + req.Author + "\nMESSAGE: " + req.Text
	answer, err := s.p.Flock.ask(s.ctx, nil, "Quill", system, prompt, budget)
	if err != nil {
		return
	}
	answer = strings.TrimSpace(answer)
	if strings.HasPrefix(answer, relayPrefix) {
		var payload struct {
			Crow string `json:"crow"`
			Task string `json:"task"`
		}
		broken := json.Unmarshal([]byte(strings.TrimSpace(strings.TrimPrefix(answer, relayPrefix))), &payload) != nil
		if !broken && slices.Contains(nest.Crows, payload.Crow) {
			s.postRelay(nest, req, payload.Crow, payload.Task)
			return
		}
		name := ""
		if !broken {
			name = payload.Crow
		}
		s.postQuillStall(nest, req, name)
		return
	}
	reply := Message{
		NestID:    nest.ID,
		Kind:      "deliver",
		Author:    "Quill",
		Text:      answer,
		To:        req.Author,
		RefersTo:  req.MsgID(),
		TaggedBy:  "harness",
		Timestamp: time.Now().UTC().Format(time.RFC3339),
	}
	if record, err := s.msgs.Append(reply); err == nil {
		s.emitNestMessage(record)
	}
}

// postRelay appends Quill's relayed request to a member crow and runs it
// through the normal response trigger, so the addressed crow must-respond as
// if the owner had asked it directly.
func (s *Server) postRelay(nest Nest, req Message, crow, task string) {
	relay := Message{
		NestID:    nest.ID,
		Kind:      "request",
		Author:    "Quill",
		Text:      task,
		To:        crow,
		RefersTo:  req.MsgID(),
		TaggedBy:  "harness",
		Timestamp: time.Now().UTC().Format(time.RFC3339),
	}
	if record, err := s.msgs.Append(relay); err == nil {
		s.emitNestMessage(record)
		s.triggerResponse(nest, record)
	}
}

// postQuillStall is the only other thing a RELAY reply can produce: one
// plain say back to the requester, naming the crow when Quill named one.
func (s *Server) postQuillStall(nest Nest, req Message, crow string) {
	text := "I could not find that crow in this nest."
	if crow != "" {
		text = "I could not find " + crow + " in this nest."
	}
	stall := Message{
		NestID:    nest.ID,
		Kind:      "say",
		Author:    "Quill",
		Text:      text,
		To:        req.Author,
		RefersTo:  req.MsgID(),
		TaggedBy:  "harness",
		Timestamp: time.Now().UTC().Format(time.RFC3339),
	}
	if record, err := s.msgs.Append(stall); err == nil {
		s.emitNestMessage(record)
	}
}