package support

import (
	"context"
	"encoding/json"
	"strings"

	"github.com/google/uuid"
)

// Queue flag filters for staff inbox (agent 8).
const (
	FlagNeedsHuman = "needs_human"
	FlagAIDraft    = "ai_draft"
)

// ApproveAIDraftInput is the staff approve payload for draft_only AI replies.
type ApproveAIDraftInput struct {
	Body   string  `json:"body"`
	Status *string `json:"status"`
}

// ApplyQueueFlag appends WHERE clauses for staff auto-assist filters.
// Unknown flags are ignored (fail open on filter only — never broaden visibility).
func ApplyQueueFlag(f *ListFilter, args *[]any, where *string) {
	if f == nil || args == nil || where == nil {
		return
	}
	flag := strings.ToLower(strings.TrimSpace(f.Flag))
	switch flag {
	case FlagAIDraft:
		*where += ` AND COALESCE(t.auto_reply_status, 'none') = 'ai_draft'`
	case FlagNeedsHuman:
		*where += ` AND COALESCE(t.auto_reply_status, 'none') IN ('handed_off','failed','skipped')`
	default:
		return
	}
}

func findAIDraftMessage(msgs []Message, preferredID *uuid.UUID) *Message {
	if preferredID != nil {
		for i := range msgs {
			if msgs[i].ID == *preferredID {
				return &msgs[i]
			}
		}
	}
	for i := len(msgs) - 1; i >= 0; i-- {
		m := &msgs[i]
		if !m.IsInternalNote {
			continue
		}
		src := strings.ToLower(strings.TrimSpace(m.AutoSource))
		if m.IsAutoReply && (src == "ai" || src == "") {
			return m
		}
		if src == "ai" {
			return m
		}
	}
	for i := len(msgs) - 1; i >= 0; i-- {
		m := &msgs[i]
		if m.IsInternalNote && m.IsAutoReply {
			return m
		}
	}
	return nil
}

// ApproveAIDraft posts an edited (or original) AI draft as a public staff reply.
// Enforces the same ticket visibility as other desk mutations via the caller.
func (s *Service) ApproveAIDraft(ctx context.Context, agentUserID, ticketID uuid.UUID, in ApproveAIDraftInput) (Ticket, error) {
	t, err := s.GetAdmin(ctx, ticketID)
	if err != nil {
		return Ticket{}, err
	}
	if strings.ToLower(strings.TrimSpace(t.AutoReplyStatus)) != AutoReplyAIDraft {
		return Ticket{}, ErrNoAIDraft
	}

	body := strings.TrimSpace(in.Body)
	if body == "" {
		draft := findAIDraftMessage(t.Messages, t.AutoReplyMessageID)
		if draft == nil {
			return Ticket{}, ErrNoAIDraft
		}
		body = draft.Body
	}

	out, err := s.ReplyAsAgent(ctx, agentUserID, ticketID, ReplyInput{
		Body:   body,
		Status: in.Status,
	})
	if err != nil {
		return Ticket{}, err
	}
	_ = out

	meta, _ := json.Marshal(map[string]any{
		"action": "approve_ai_draft",
		"by":     agentUserID.String(),
	})
	_ = s.RecordAutoReplyOutcome(ctx, ticketID, AutoReplyAISent, true, nil, meta, ActivityAISent)

	return s.GetAdmin(ctx, ticketID)
}

// DiscardAIDraft marks the ticket as handed off, disables further auto, and keeps the internal note.
func (s *Service) DiscardAIDraft(ctx context.Context, agentUserID, ticketID uuid.UUID) (Ticket, error) {
	t, err := s.GetAdmin(ctx, ticketID)
	if err != nil {
		return Ticket{}, err
	}
	status := strings.ToLower(strings.TrimSpace(t.AutoReplyStatus))
	draft := findAIDraftMessage(t.Messages, t.AutoReplyMessageID)
	if status != AutoReplyAIDraft && draft == nil {
		return Ticket{}, ErrNoAIDraft
	}

	disabled := true
	if _, err := s.UpdateAdmin(ctx, ticketID, agentUserID, AdminUpdateInput{
		AutoReplyDisabled: &disabled,
	}); err != nil {
		return Ticket{}, err
	}

	meta, _ := json.Marshal(map[string]any{
		"action": "discard_ai_draft",
		"by":     agentUserID.String(),
	})
	if err := s.RecordAutoReplyOutcome(ctx, ticketID, AutoReplyHandedOff, true, t.AutoReplyMessageID, meta, ActivityHandedOff); err != nil {
		return Ticket{}, err
	}
	return s.GetAdmin(ctx, ticketID)
}