package model

import (
	"time"

	"github.com/heicode/manager/common"
)

// AgentAuditEvent is the persistent audit-trail row for the Agent
// control-plane. Each row records one observable transition in the
// Agent lifecycle — deployment accepted, instance phase changed, SK
// snapshot refreshed, etc. — so admins can answer the "who / when /
// for which task / against which resource / with what result" set of
// questions even after the Manager container restarts.
//
// Before this table existed the control-plane stashed events in an
// in-process `map[string][]agentEvent` (controller/agent_control_plane
// .go:219). Every restart wiped audit history — unacceptable for a
// product where the audit page is part of the security story.
//
// Schema notes
//   - All string columns are bounded varchar to keep MySQL happy.
//   - `OccurredAt` is unix milliseconds so cross-DB ORDER BY / range
//     queries are trivial without a TIMESTAMP-with-timezone dance.
//   - `DetailsJSON` is a free-form payload bucket for fields we don't
//     want to promote to first-class columns yet (e.g. failure_reason,
//     phase, callback_url). Add a real column when a field is queried
//     enough to need an index.
//   - Indexes are picked for the dashboard queries: filter by user_id,
//     filter by deployment, time-range scan.
//
// Cross-DB compatibility (CLAUDE.md Rule 2): GORM AutoMigrate maps the
// tags to the correct types on SQLite / MySQL / PostgreSQL. No raw
// SQL. No DB-specific column types.
type AgentAuditEvent struct {
	Id            int    `gorm:"primaryKey" json:"id"`
	EventID       string `gorm:"type:varchar(64);uniqueIndex" json:"event_id"`
	Event         string `gorm:"type:varchar(64);index" json:"event"`
	Actor         string `gorm:"type:varchar(64)" json:"actor"`
	Resource      string `gorm:"type:varchar(128);index" json:"resource"`
	UserID        string `gorm:"type:varchar(64);index" json:"user_id"`
	ChannelID     string `gorm:"type:varchar(64)" json:"channel_id"`
	BindingScope  string `gorm:"type:varchar(64);index" json:"binding_scope"`
	DeploymentID  string `gorm:"type:varchar(64);index" json:"deployment_id"`
	CorrelationID string `gorm:"type:varchar(64)" json:"correlation_id"`
	RequestID     string `gorm:"type:varchar(64)" json:"request_id"`
	Result        string `gorm:"type:varchar(16)" json:"result"`
	SchemaVersion int    `gorm:"default:1" json:"schema_version"`
	OccurredAt    int64  `gorm:"bigint;index" json:"occurred_at"`
	DetailsJSON   string `gorm:"type:text" json:"details_json,omitempty"`
}

// TableName pins the migration target so we can rename the Go struct
// later without breaking the deployed schema.
func (AgentAuditEvent) TableName() string {
	return "agent_audit_events"
}

// InsertAgentAuditEvent best-effort persists one audit row. Callers
// invoke this in a hot path (right after mutating a deployment), so:
//   - errors are logged but never returned — the audit write must NOT
//     fail the user-facing API
//   - DB is nil-guarded so unit tests / partial-init binaries don't
//     panic on a missing connection
func InsertAgentAuditEvent(evt *AgentAuditEvent) {
	if DB == nil || evt == nil {
		return
	}
	if evt.OccurredAt == 0 {
		evt.OccurredAt = time.Now().UnixMilli()
	}
	if evt.SchemaVersion == 0 {
		evt.SchemaVersion = 1
	}
	if evt.Result == "" {
		evt.Result = "ok"
	}
	if err := DB.Create(evt).Error; err != nil {
		common.SysLog("InsertAgentAuditEvent: " + err.Error())
	}
}

// ListAgentAuditEventsFilter narrows the audit query to a slice of
// dashboard relevant rows. Zero-value fields are ignored — callers
// pass only the filters they care about.
type ListAgentAuditEventsFilter struct {
	UserID       string
	BindingScope string
	DeploymentID string
	EventLike    string // prefix filter on Event column, e.g. "deployment."
	FromMs       int64  // inclusive
	ToMs         int64  // exclusive; zero == no upper bound
	Limit        int    // defaults to 200
	Offset       int
}

// ListAgentAuditEvents pages over audit rows ordered newest-first.
// Used by the /api/agent/audit-logs endpoint and the future task-
// scoped audit drawer.
func ListAgentAuditEvents(f ListAgentAuditEventsFilter) ([]AgentAuditEvent, int64, error) {
	if DB == nil {
		return nil, 0, nil
	}
	q := DB.Model(&AgentAuditEvent{})
	if f.UserID != "" {
		q = q.Where("user_id = ?", f.UserID)
	}
	if f.BindingScope != "" {
		q = q.Where("binding_scope = ?", f.BindingScope)
	}
	if f.DeploymentID != "" {
		q = q.Where("deployment_id = ?", f.DeploymentID)
	}
	if f.EventLike != "" {
		q = q.Where("event LIKE ?", f.EventLike+"%")
	}
	if f.FromMs > 0 {
		q = q.Where("occurred_at >= ?", f.FromMs)
	}
	if f.ToMs > 0 {
		q = q.Where("occurred_at < ?", f.ToMs)
	}
	var total int64
	if err := q.Count(&total).Error; err != nil {
		return nil, 0, err
	}
	limit := f.Limit
	if limit <= 0 || limit > 1000 {
		limit = 200
	}
	var items []AgentAuditEvent
	err := q.Order("occurred_at desc, id desc").Limit(limit).Offset(f.Offset).Find(&items).Error
	return items, total, err
}

// ListAgentAuditEventsByDeployment is the hot path for the deployment
// detail drawer — returns all events for one deployment in chronological
// order so the timeline reads top-to-bottom.
func ListAgentAuditEventsByDeployment(deploymentID string) ([]AgentAuditEvent, error) {
	if DB == nil || deploymentID == "" {
		return nil, nil
	}
	var items []AgentAuditEvent
	err := DB.Where("deployment_id = ?", deploymentID).
		Order("occurred_at asc, id asc").
		Find(&items).Error
	return items, err
}