package repository

import (
	"context"
	"errors"
	"time"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
)

// AskSessionView is ops read meta for one ask thread.
type AskSessionView struct {
	ID           uuid.UUID `json:"id"`
	UserID       uuid.UUID `json:"user_id"`
	ProfileID    uuid.UUID `json:"profile_id"`
	Scene        *string   `json:"scene,omitempty"`
	MessageCount int       `json:"message_count"`
	CreatedAt    time.Time `json:"created_at"`
	UpdatedAt    time.Time `json:"updated_at"`
}

// AskMessageView is a read-only message row for ops.
type AskMessageView struct {
	ID        uuid.UUID `json:"id"`
	Role      string    `json:"role"`
	Content   string    `json:"content"`
	CreatedAt time.Time `json:"created_at"`
}

// ListAskSessions returns recent ask threads (optional user filter).
func (r *AdminRepo) ListAskSessions(ctx context.Context, userID *uuid.UUID, limit, offset int) ([]AskSessionView, error) {
	if limit <= 0 || limit > 100 {
		limit = 20
	}
	if offset < 0 {
		offset = 0
	}
	rows, err := r.Pool.Query(ctx, `
		SELECT t.id, t.user_id, t.profile_id, t.scene, t.created_at, t.updated_at,
			(SELECT count(*)::int FROM ask_messages m
			 WHERE m.thread_id=t.id AND m.deleted_at IS NULL) AS message_count
		FROM ask_threads t
		WHERE t.deleted_at IS NULL
		  AND ($1::uuid IS NULL OR t.user_id=$1)
		ORDER BY t.updated_at DESC
		LIMIT $2 OFFSET $3`, userID, limit, offset)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []AskSessionView
	for rows.Next() {
		var s AskSessionView
		if err := rows.Scan(
			&s.ID, &s.UserID, &s.ProfileID, &s.Scene, &s.CreatedAt, &s.UpdatedAt, &s.MessageCount,
		); err != nil {
			return nil, err
		}
		out = append(out, s)
	}
	return out, rows.Err()
}

// GetAskSession loads one thread meta or ErrNoRows.
func (r *AdminRepo) GetAskSession(ctx context.Context, threadID uuid.UUID) (*AskSessionView, error) {
	var s AskSessionView
	err := r.Pool.QueryRow(ctx, `
		SELECT t.id, t.user_id, t.profile_id, t.scene, t.created_at, t.updated_at,
			(SELECT count(*)::int FROM ask_messages m
			 WHERE m.thread_id=t.id AND m.deleted_at IS NULL) AS message_count
		FROM ask_threads t
		WHERE t.id=$1 AND t.deleted_at IS NULL`, threadID,
	).Scan(&s.ID, &s.UserID, &s.ProfileID, &s.Scene, &s.CreatedAt, &s.UpdatedAt, &s.MessageCount)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, err
	}
	if err != nil {
		return nil, err
	}
	return &s, nil
}

// ListAskMessagesForAdmin returns messages oldest-first.
func (r *AdminRepo) ListAskMessagesForAdmin(ctx context.Context, threadID uuid.UUID) ([]AskMessageView, error) {
	rows, err := r.Pool.Query(ctx, `
		SELECT id, role, content, created_at
		FROM ask_messages
		WHERE thread_id=$1 AND deleted_at IS NULL
		ORDER BY created_at ASC`, threadID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []AskMessageView
	for rows.Next() {
		var m AskMessageView
		if err := rows.Scan(&m.ID, &m.Role, &m.Content, &m.CreatedAt); err != nil {
			return nil, err
		}
		out = append(out, m)
	}
	return out, rows.Err()
}