package store

import (
	"database/sql"
	"errors"
	"strconv"
	"strings"
)

// 套餐计费方式：lite 版只有「按日」一种，
// 但 packages.unit 列保留（写入固定值 "day"），以便老库平滑升级。
const unitDay = "day"

// Package 服务套餐。
type Package struct {
	ID            int64
	Name          string
	DefaultAmount int // 默认天数
	PriceCents    int
	HasPrice      bool
	Color         string
	Note          string
	Archived      bool
	SortOrder     int
	// CalendarSeparate 勾选后在工作台日历中单独成页
	CalendarSeparate bool
	// Tag 套餐标签：相同标签的套餐在日历里合并显示
	Tag       string
	CreatedAt string
	UpdatedAt string
	SubCount  int
	ActiveCount int
}

// UnitLabel 返回类型中文名（lite 版只有按日）。
func (p *Package) UnitLabel() string { return "按日" }

// AmountText 返回「默认量」列的中文描述。
func (p *Package) AmountText() string {
	return strconv.Itoa(p.DefaultAmount) + " 天"
}

const packageCols = `id,name,unit,default_amount,price_cents,color,note,archived,sort_order,calendar_separate,tag,created_at,updated_at`

func scanPackage(row interface{ Scan(dest ...any) error }) (*Package, error) {
	var p Package
	var unit string
	var price sql.NullInt64
	var archived, separate int
	err := row.Scan(&p.ID, &p.Name, &unit, &p.DefaultAmount, &price, &p.Color, &p.Note,
		&archived, &p.SortOrder, &separate, &p.Tag, &p.CreatedAt, &p.UpdatedAt)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	p.Archived = archived == 1
	p.CalendarSeparate = separate == 1
	if price.Valid {
		p.PriceCents = int(price.Int64)
		p.HasPrice = true
	}
	return &p, nil
}

// ListPackages 列出套餐（含订阅计数）。
func (db *DB) ListPackages(includeArchived bool) ([]Package, error) {
	q := `SELECT p.id,p.name,p.unit,p.default_amount,p.price_cents,p.color,p.note,p.archived,p.sort_order,p.calendar_separate,p.tag,p.created_at,p.updated_at,
		(SELECT COUNT(*) FROM subscriptions s WHERE s.package_id=p.id),
		(SELECT COUNT(*) FROM subscriptions s WHERE s.package_id=p.id AND s.status<>'closed')
		FROM packages p`
	if !includeArchived {
		q += ` WHERE p.archived=0`
	}
	q += ` ORDER BY p.archived, p.sort_order, p.id`
	rows, err := db.sql.Query(q)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []Package{}
	for rows.Next() {
		var p Package
		var unit string
		var price sql.NullInt64
		var archived, separate int
		if err := rows.Scan(&p.ID, &p.Name, &unit, &p.DefaultAmount, &price, &p.Color, &p.Note,
			&archived, &p.SortOrder, &separate, &p.Tag, &p.CreatedAt, &p.UpdatedAt, &p.SubCount, &p.ActiveCount); err != nil {
			return nil, err
		}
		p.Archived = archived == 1
		p.CalendarSeparate = separate == 1
		if price.Valid {
			p.PriceCents = int(price.Int64)
			p.HasPrice = true
		}
		out = append(out, p)
	}
	return out, rows.Err()
}

// Package 取单个套餐。
func (db *DB) Package(id int64) (*Package, error) {
	return scanPackage(db.sql.QueryRow(`SELECT `+packageCols+` FROM packages WHERE id=?`, id))
}

func (p *Package) normalize() {
	if p.DefaultAmount <= 0 {
		p.DefaultAmount = 30
	}
	if strings.TrimSpace(p.Color) == "" {
		p.Color = "#3B6EA5"
	}
}

// CreatePackage 新建套餐。
func (db *DB) CreatePackage(p *Package) (int64, error) {
	now := nowStamp()
	p.normalize()
	var price any
	if p.HasPrice {
		price = p.PriceCents
	}
	res, err := db.sql.Exec(`INSERT INTO packages(name,unit,default_amount,price_cents,color,note,archived,sort_order,calendar_separate,tag,created_at,updated_at)
		VALUES(?,?,?,?,?,?,0,?,?,?,?,?)`,
		p.Name, unitDay, p.DefaultAmount, price, p.Color, p.Note, p.SortOrder, b2i(p.CalendarSeparate), strings.TrimSpace(p.Tag), now, now)
	if err != nil {
		return 0, err
	}
	return res.LastInsertId()
}

// UpdatePackage 更新套餐。
func (db *DB) UpdatePackage(p *Package) error {
	p.normalize()
	var price any
	if p.HasPrice {
		price = p.PriceCents
	}
	_, err := db.sql.Exec(`UPDATE packages SET name=?,unit=?,default_amount=?,price_cents=?,color=?,note=?,sort_order=?,calendar_separate=?,tag=?,updated_at=?
		WHERE id=?`, p.Name, unitDay, p.DefaultAmount, price, p.Color, p.Note, p.SortOrder, b2i(p.CalendarSeparate), strings.TrimSpace(p.Tag), nowStamp(), p.ID)
	return err
}

// b2i 把 bool 转成 SQLite 的 0/1。
func b2i(v bool) int {
	if v {
		return 1
	}
	return 0
}

// SetPackageArchived 归档/取消归档。
func (db *DB) SetPackageArchived(id int64, archived bool) error {
	v := 0
	if archived {
		v = 1
	}
	_, err := db.sql.Exec(`UPDATE packages SET archived=?, updated_at=? WHERE id=?`, v, nowStamp(), id)
	return err
}

// SubscribedCustomerIDs 返回已订阅某套餐的客户 ID 集合（含已关闭，用于批量订阅时置灰）。
func (db *DB) SubscribedCustomerIDs(packageID int64) (map[int64]bool, error) {
	rows, err := db.sql.Query(`SELECT customer_id FROM subscriptions WHERE package_id=?`, packageID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := map[int64]bool{}
	for rows.Next() {
		var id int64
		if err := rows.Scan(&id); err != nil {
			return nil, err
		}
		out[id] = true
	}
	return out, rows.Err()
}

// PackageTags 返回所有非空标签（去重，按字典序）。
func (db *DB) PackageTags() ([]string, error) {
	rows, err := db.sql.Query(`SELECT DISTINCT tag FROM packages WHERE IFNULL(tag,'')<>'' ORDER BY tag`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []string{}
	for rows.Next() {
		var t string
		if err := rows.Scan(&t); err != nil {
			return nil, err
		}
		out = append(out, t)
	}
	return out, rows.Err()
}