package store

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

	"provisioning/internal/model"
)

type Operations struct {
	DB *sql.DB
}

func (s *Operations) Create(ctx context.Context, op model.Operation) (int64, error) {
	res, err := s.DB.ExecContext(ctx, `
		INSERT INTO operations(host_id, kind, state, image_id)
		VALUES(?,?,?,?)
	`, op.HostID, op.Kind, model.OpActive, nullInt64(op.ImageID))
	if err != nil {
		return 0, fmt.Errorf("insert operation: %w", err)
	}
	return res.LastInsertId()
}

func (s *Operations) Complete(ctx context.Context, id int64) error {
	_, err := s.DB.ExecContext(ctx, `UPDATE operations SET state = ?, completed_at = strftime('%Y-%m-%dT%H:%M:%SZ','now') WHERE id = ?`, model.OpCompleted, id)
	return err
}

func (s *Operations) Fail(ctx context.Context, id int64, errMsg string) error {
	_, err := s.DB.ExecContext(ctx, `UPDATE operations SET state = ?, completed_at = strftime('%Y-%m-%dT%H:%M:%SZ','now'), error_message = ? WHERE id = ?`, model.OpFailed, errMsg, id)
	return err
}

func (s *Operations) ListByHost(ctx context.Context, hostID int64) ([]model.Operation, error) {
	rows, err := s.DB.QueryContext(ctx, `
		SELECT id, host_id, kind, state, COALESCE(image_id, 0), started_at, completed_at, COALESCE(error_message, '')
		FROM operations WHERE host_id = ? ORDER BY started_at DESC
	`, hostID)
	if err != nil {
		return nil, fmt.Errorf("list operations: %w", err)
	}
	defer rows.Close()
	var out []model.Operation
	for rows.Next() {
		var op model.Operation
		var startedAt string
		var completedAt sql.NullString
		if err := rows.Scan(&op.ID, &op.HostID, &op.Kind, &op.State, &op.ImageID, &startedAt, &completedAt, &op.ErrorMessage); err != nil {
			return nil, fmt.Errorf("scan operation: %w", err)
		}
		op.StartedAt, _ = time.Parse(time.RFC3339, startedAt)
		if completedAt.Valid {
			t, _ := time.Parse(time.RFC3339, completedAt.String)
			op.CompletedAt = &t
		}
		out = append(out, op)
	}
	return out, rows.Err()
}

func (s *Operations) GetActive(ctx context.Context, hostID int64) (*model.Operation, error) {
	row := s.DB.QueryRowContext(ctx, `
		SELECT id, host_id, kind, state, COALESCE(image_id, 0), started_at, completed_at, COALESCE(error_message, '')
		FROM operations WHERE host_id = ? AND state = ? ORDER BY started_at DESC LIMIT 1
	`, hostID, model.OpActive)
	var op model.Operation
	var startedAt string
	var completedAt sql.NullString
	if err := row.Scan(&op.ID, &op.HostID, &op.Kind, &op.State, &op.ImageID, &startedAt, &completedAt, &op.ErrorMessage); err != nil {
		if err == sql.ErrNoRows {
			return nil, ErrNotFound
		}
		return nil, fmt.Errorf("get active operation: %w", err)
	}
	op.StartedAt, _ = time.Parse(time.RFC3339, startedAt)
	return &op, nil
}

func nullInt64(v int64) any {
	if v == 0 {
		return nil
	}
	return v
}