package wait

import (
	"context"
	"strings"
	"time"
)

// Implement interface
var (
	_ Strategy        = (*ExitStrategy)(nil)
	_ StrategyTimeout = (*ExitStrategy)(nil)
)

// ExitStrategy will wait until container exit
type ExitStrategy struct {
	// all Strategies should have a timeout to avoid waiting infinitely
	timeout *time.Duration

	// additional properties
	PollInterval time.Duration
}

// NewExitStrategy constructs with polling interval of 100 milliseconds without timeout by default
func NewExitStrategy() *ExitStrategy {
	return &ExitStrategy{
		PollInterval: defaultPollInterval(),
	}
}

// fluent builders for each property
// since go has neither covariance nor generics, the return type must be the type of the concrete implementation
// this is true for all properties, even the "shared" ones

// WithExitTimeout can be used to change the default exit timeout
func (ws *ExitStrategy) WithExitTimeout(exitTimeout time.Duration) *ExitStrategy {
	ws.timeout = &exitTimeout
	return ws
}

// WithPollInterval can be used to override the default polling interval of 100 milliseconds
func (ws *ExitStrategy) WithPollInterval(pollInterval time.Duration) *ExitStrategy {
	ws.PollInterval = pollInterval
	return ws
}

// ForExit is the default construction for the fluid interface.
//
// For Example:
//
//	wait.
//		ForExit().
//		WithPollInterval(1 * time.Second)
func ForExit() *ExitStrategy {
	return NewExitStrategy()
}

func (ws *ExitStrategy) Timeout() *time.Duration {
	return ws.timeout
}

// WaitUntilReady implements Strategy.WaitUntilReady
func (ws *ExitStrategy) WaitUntilReady(ctx context.Context, target StrategyTarget) error {
	if ws.timeout != nil {
		var cancel context.CancelFunc
		ctx, cancel = context.WithTimeout(ctx, *ws.timeout)
		defer cancel()
	}

	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
			state, err := target.State(ctx)
			if err != nil {
				if !strings.Contains(err.Error(), "No such container") {
					return err
				} else {
					return nil
				}
			}
			if state.Running {
				time.Sleep(ws.PollInterval)
				continue
			}
			return nil
		}
	}
}