package db

import (
	"context"
	"database/sql"
	"time"
)

type AuditLogEntry struct {
	ID         int64
	AdminID    int64
	Action     string
	EntityType string
	EntityID   sql.NullInt64
	OldValue   sql.NullString
	NewValue   sql.NullString
	IPAddress  string
	CreatedAt  time.Time
}

// Audit action constants
const (
	AuditCreatePanel      = "create_panel"
	AuditUpdatePanel      = "update_panel"
	AuditDeletePanel      = "delete_panel"
	AuditCreateType       = "create_type"
	AuditUpdateType       = "update_type"
	AuditDeleteType       = "delete_type"
	AuditReorderTypes     = "reorder_types"
	AuditUpdateConvoc     = "update_convocation"
	AuditSendPanelDiscord = "send_panel_discord"
	AuditDeletePanelMsg   = "delete_panel_discord"
	AuditRevokeSession    = "revoke_session"
	AuditRevokeAllSess    = "revoke_all_sessions"
	AuditAdminLogin       = "admin_login"
	AuditAdminLoginFail   = "admin_login_failed"
	AuditAdminLocked      = "admin_locked"
)

type AuditFilter struct {
	AdminID    int64
	Action     string
	EntityType string
	From, To   time.Time
}

type AuditLogRepo struct{ db *sql.DB }

func NewAuditLogRepo(db *sql.DB) *AuditLogRepo { return &AuditLogRepo{db: db} }

func (r *AuditLogRepo) Insert(ctx context.Context, e *AuditLogEntry) error {
	e.CreatedAt = time.Now().UTC()
	_, err := r.db.ExecContext(ctx,
		`INSERT INTO audit_log(admin_id,action,entity_type,entity_id,old_value,new_value,ip_address,created_at)
		 VALUES(?,?,?,?,?,?,?,?)`,
		e.AdminID, e.Action, e.EntityType, e.EntityID, e.OldValue, e.NewValue, e.IPAddress, e.CreatedAt)
	return err
}

func (r *AuditLogRepo) List(ctx context.Context, f AuditFilter, page, pageSize int) ([]*AuditLogEntry, int, error) {
	where := "WHERE 1=1"
	args := []any{}
	if f.AdminID != 0 {
		where += " AND admin_id=?"
		args = append(args, f.AdminID)
	}
	if f.Action != "" {
		where += " AND action=?"
		args = append(args, f.Action)
	}
	if f.EntityType != "" {
		where += " AND entity_type=?"
		args = append(args, f.EntityType)
	}
	if !f.From.IsZero() {
		where += " AND created_at>=?"
		args = append(args, f.From)
	}
	if !f.To.IsZero() {
		where += " AND created_at<=?"
		args = append(args, f.To)
	}

	var total int
	countArgs := make([]any, len(args))
	copy(countArgs, args)
	if err := r.db.QueryRowContext(ctx, `SELECT COUNT(*) FROM audit_log `+where, countArgs...).Scan(&total); err != nil {
		return nil, 0, err
	}

	if page < 1 {
		page = 1
	}
	offset := (page - 1) * pageSize
	args = append(args, pageSize, offset)
	rows, err := r.db.QueryContext(ctx,
		`SELECT id,admin_id,action,entity_type,entity_id,old_value,new_value,ip_address,created_at
		 FROM audit_log `+where+` ORDER BY created_at DESC LIMIT ? OFFSET ?`, args...)
	if err != nil {
		return nil, 0, err
	}
	defer rows.Close()

	var out []*AuditLogEntry
	for rows.Next() {
		var e AuditLogEntry
		if err := rows.Scan(&e.ID, &e.AdminID, &e.Action, &e.EntityType, &e.EntityID,
			&e.OldValue, &e.NewValue, &e.IPAddress, &e.CreatedAt); err != nil {
			return nil, 0, err
		}
		out = append(out, &e)
	}
	return out, total, rows.Err()
}