package store

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

// AuditEvent is one change: who made it, through what, to what, and how it
// ended. Detail never holds a secret; the writer takes them out.
type AuditEvent struct {
	ID     int64     `json:"id"`
	At     time.Time `json:"at"`
	Actor  string    `json:"actor"`
	Source string    `json:"source"` // api, web
	Action string    `json:"action"` // "POST /api/v1/models", "POST /admin/users/{id}/suspend"
	Target string    `json:"target,omitempty"`
	Detail string    `json:"detail,omitempty"`
	Status int       `json:"status"`
}

// WriteAudit records one change.
func (s *DB) WriteAudit(ctx context.Context, e AuditEvent) error {
	if e.At.IsZero() {
		e.At = time.Now()
	}
	_, err := s.db.ExecContext(ctx, `INSERT INTO audit_events (ts, actor, source, action, target, detail, status)
		VALUES (?, ?, ?, ?, ?, ?, ?)`, millis(e.At), e.Actor, e.Source, e.Action, e.Target, e.Detail, e.Status)
	return err
}

// AuditFilter narrows a listing; empty fields match everything.
type AuditFilter struct {
	Since, Until time.Time
	Actor        string
	// Contains matches the action or the target.
	Contains string
	Limit    int
}

// AuditEvents lists changes, the newest first.
func (s *DB) AuditEvents(ctx context.Context, f AuditFilter) ([]AuditEvent, error) {
	q := `SELECT id, ts, actor, source, action, target, detail, status FROM audit_events WHERE ts >= ?`
	args := []any{millis(f.Since)}
	if !f.Until.IsZero() {
		q += ` AND ts < ?`
		args = append(args, millis(f.Until))
	}
	if f.Actor != "" {
		q += ` AND actor = ?`
		args = append(args, f.Actor)
	}
	if f.Contains != "" {
		q += ` AND (LOWER(action) LIKE ? OR LOWER(target) LIKE ?)`
		like := "%" + strings.ToLower(f.Contains) + "%"
		args = append(args, like, like)
	}
	limit := f.Limit
	if limit <= 0 || limit > 10000 {
		limit = 200
	}
	q += ` ORDER BY ts DESC, id DESC LIMIT ?`
	args = append(args, limit)
	return queryAll(ctx, s.db, q, args, func(rows *sql.Rows) (AuditEvent, error) {
		var e AuditEvent
		var ts int64
		err := rows.Scan(&e.ID, &ts, &e.Actor, &e.Source, &e.Action, &e.Target, &e.Detail, &e.Status)
		e.At = fromMillis(ts)
		return e, err
	})
}