package store

import (
	"time"

	"github.com/shopspring/decimal"
	"gorm.io/gorm"
)

// User is a registered account.
type User struct {
	ID           int64  `gorm:"primaryKey"`
	Username     string `gorm:"uniqueIndex;size:64"`
	Email        string `gorm:"uniqueIndex;size:255"`
	PasswordHash string `gorm:"size:255"`
	Role         string `gorm:"size:16;default:user"` // admin | user
	Balance      decimal.Decimal `gorm:"type:numeric(20,8);default:0"`
	Status       string `gorm:"size:16;default:active"` // active | disabled
	InviteCode   string `gorm:"size:64"`
	LastLoginAt  *time.Time
	CreatedAt    time.Time
	UpdatedAt    time.Time
}

// ApiKey is an API key issued to a user.
type ApiKey struct {
	ID                    int64  `gorm:"primaryKey"`
	UserID                int64  `gorm:"index"`
	Name                  string `gorm:"size:128"`
	KeyHash               string `gorm:"uniqueIndex;size:128"`
	KeyPrefix             string `gorm:"size:16"`
	QuotaTokensPerDay     *int64
	QuotaRequestsPerDay   *int
	AllowedModels         []string `gorm:"serializer:json"`
	ExpiresAt             *time.Time
	Status                string `gorm:"size:16;default:active"` // active | revoked
	LastUsedAt            *time.Time
	CreatedAt             time.Time
	UpdatedAt             time.Time
}

// Channel is an upstream provider.
type Channel struct {
	ID              int64  `gorm:"primaryKey"`
	Name            string `gorm:"size:128"`
	Provider        string `gorm:"size:32"` // openai | anthropic | compatible
	BaseURL         string `gorm:"size:512"`
	APIKeyEnc       string `gorm:"size:2048"` // AES-GCM ciphertext
	Weight          int    `gorm:"default:1"`
	Priority        int    `gorm:"default:0"` // lower = preferred
	TimeoutMs       int    `gorm:"default:300000"`
	MaxConcurrency  int    `gorm:"default:100"`
	HealthStatus    string `gorm:"size:16;default:healthy"` // healthy | degraded | cooldown
	HealthFailures  int
	Enabled         bool     `gorm:"default:true"`
	Formats         []string `gorm:"serializer:json"` // client API formats served natively; empty = derive from Provider
	CreatedAt       time.Time
	UpdatedAt       time.Time
}

// Client API format keys a channel can serve natively. They match the proxy
// route protocol values so SupportsFormat can compare them directly.
const (
	FormatOpenAIChat      = "openai-chat"
	FormatOpenAIResponses = "openai-responses"
	FormatAnthropic       = "anthropic"
)

// FormatsResolved returns the API formats the channel serves directly. When
// Formats is empty it falls back to the provider's native formats so legacy
// rows behave exactly as before.
func (c *Channel) FormatsResolved() []string {
	if len(c.Formats) > 0 {
		out := make([]string, len(c.Formats))
		copy(out, c.Formats)
		return out
	}
	if c.Provider == "anthropic" {
		return []string{FormatAnthropic}
	}
	return []string{FormatOpenAIChat, FormatOpenAIResponses}
}

// SupportsFormat reports whether the channel serves a client protocol
// natively (passthrough) without conversion.
func (c *Channel) SupportsFormat(f string) bool {
	for _, x := range c.FormatsResolved() {
		if x == f {
			return true
		}
	}
	return false
}

// Model is the global model registry with pricing.
type Model struct {
	ID              int64  `gorm:"primaryKey"`
	Name            string `gorm:"uniqueIndex;size:128"`
	DisplayName     string `gorm:"size:255"`
	InputPrice      decimal.Decimal `gorm:"type:numeric(20,8);default:0"` // per 1M tokens
	OutputPrice     decimal.Decimal `gorm:"type:numeric(20,8);default:0"`
	CacheReadPrice  decimal.Decimal `gorm:"type:numeric(20,8);default:0"`
	Enabled         bool   `gorm:"default:true"`
	Sort            int    `gorm:"default:0"`
	CreatedAt       time.Time
	UpdatedAt       time.Time
}

// ChannelModelBinding binds a global model to a channel with an upstream name.
type ChannelModelBinding struct {
	ID            int64 `gorm:"primaryKey"`
	ChannelID     int64 `gorm:"index;uniqueIndex:idx_channel_model"`
	ModelID       int64 `gorm:"index;uniqueIndex:idx_channel_model"`
	UpstreamModel string `gorm:"size:255"`
	Weight        int    `gorm:"default:1"`
	Channel       Channel `gorm:"foreignKey:ChannelID"`
	Model         Model   `gorm:"foreignKey:ModelID"`
}

// UsageLog is one proxied request's billing record.
type UsageLog struct {
	ID                  int64  `gorm:"primaryKey"`
	RequestID           string `gorm:"size:128"`
	UserID              int64  `gorm:"index:idx_user_created,priority:1"`
	KeyID               int64
	ChannelID           int64
	ModelID             int64
	ModelName           string `gorm:"size:128"`
	InputTokens         int64
	OutputTokens        int64
	CacheReadTokens     int64
	CacheCreationTokens int64
	InputPrice          decimal.Decimal `gorm:"type:numeric(20,8)"`
	OutputPrice         decimal.Decimal `gorm:"type:numeric(20,8)"`
	CacheReadPrice      decimal.Decimal `gorm:"type:numeric(20,8)"`
	Cost                decimal.Decimal `gorm:"type:numeric(20,8)"`
	LatencyMs           int
	Status              string `gorm:"size:16"` // success | error | canceled
	ErrorCode           string `gorm:"size:64"`
	CreatedAt           time.Time `gorm:"index:idx_user_created,priority:2"`
}

// UsageDaily is the pre-aggregated per-user per-model daily rollup.
type UsageDaily struct {
	ID                 int64  `gorm:"primaryKey"`
	UserID             int64  `gorm:"index:idx_user_date,priority:1"`
	ModelID            int64
	Date               string `gorm:"size:10;index:idx_user_date,priority:2"` // YYYY-MM-DD
	Requests           int
	InputTokens        int64
	OutputTokens       int64
	CacheReadTokens    int64
	CacheCreationTokens int64
	Cost               decimal.Decimal `gorm:"type:numeric(20,8)"`
}

// RechargeOrder is reserved for the (paused) recharge feature.
type RechargeOrder struct {
	ID            int64 `gorm:"primaryKey"`
	UserID        int64 `gorm:"index"`
	Amount        decimal.Decimal `gorm:"type:numeric(20,8)"`
	Status        string `gorm:"size:16;default:pending"` // pending | credited | rejected
	Method        string `gorm:"size:16;default:manual"`  // manual | online
	TransactionID string `gorm:"size:128"`
	ReviewedBy    *int64
	ReviewedAt    *time.Time
	Remark        string `gorm:"size:512"`
	CreatedAt     time.Time
	UpdatedAt     time.Time
	User          User `gorm:"foreignKey:UserID"`
}

// BalanceLog is a user balance ledger entry.
type BalanceLog struct {
	ID           int64 `gorm:"primaryKey"`
	UserID       int64 `gorm:"index:idx_balance_user_created,priority:1"`
	Change       decimal.Decimal `gorm:"type:numeric(20,8)"`
	BalanceAfter decimal.Decimal `gorm:"type:numeric(20,8)"`
	Type         string `gorm:"size:32"` // recharge | usage | refund | admin_adjust
	RefID        string `gorm:"size:128"`
	CreatedAt    time.Time `gorm:"index:idx_balance_user_created,priority:2"`
}

// SystemConfig is a key/value store for runtime settings.
type SystemConfig struct {
	Key   string `gorm:"primaryKey;size:128"`
	Value []byte `gorm:"serializer:json"`
}

// Migrate creates/upgrades the schema.
func Migrate(db *gorm.DB) error {
	return db.AutoMigrate(
		&User{}, &ApiKey{}, &Channel{}, &Model{}, &ChannelModelBinding{},
		&UsageLog{}, &UsageDaily{}, &RechargeOrder{}, &BalanceLog{}, &SystemConfig{},
	)
}