package updater

import (
	"context"
	"fmt"
	"os/exec"
	"strings"

	"github.com/shcizo/package-updater/internal/discovery"
)

// ComposeExecutor invokes `docker compose` as a subprocess.
type ComposeExecutor struct{}

// NewComposeExecutor returns an executor that shells out to docker compose.
func NewComposeExecutor() *ComposeExecutor {
	return &ComposeExecutor{}
}

// Execute runs `docker compose -f <file>... -p <project> pull <service>`
// followed by `... up -d <service>`. Working directory is set to
// job.WorkingDir so any relative paths in the compose file resolve correctly.
func (e *ComposeExecutor) Execute(ctx context.Context, job discovery.Job) error {
	if job.Refused {
		return fmt.Errorf("refused: %s", job.RefusedReason)
	}
	if err := e.run(ctx, job, "pull"); err != nil {
		return fmt.Errorf("pull: %w", err)
	}
	if err := e.run(ctx, job, "up", "-d"); err != nil {
		return fmt.Errorf("up: %w", err)
	}
	return nil
}

func (e *ComposeExecutor) run(ctx context.Context, job discovery.Job, args ...string) error {
	cliArgs := []string{"compose"}
	for _, f := range job.ConfigFiles {
		cliArgs = append(cliArgs, "-f", f)
	}
	cliArgs = append(cliArgs, "-p", job.Project)
	cliArgs = append(cliArgs, args...)
	cliArgs = append(cliArgs, job.Service)

	cmd := exec.CommandContext(ctx, "docker", cliArgs...)
	cmd.Dir = job.WorkingDir

	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("docker %s: %w (output: %s)",
			strings.Join(args, " "), err, strings.TrimSpace(string(out)))
	}
	return nil
}