package cli

import (
	"context"
	"fmt"
	"log/slog"
	"os"
	"os/signal"
	"syscall"

	"github.com/claudomator/claudomator/internal/executor"
	"github.com/claudomator/claudomator/internal/storage"
	"github.com/claudomator/claudomator/internal/task"
	"github.com/spf13/cobra"
)

func newRunCmd() *cobra.Command {
	var (
		parallel int
		dryRun   bool
	)

	cmd := &cobra.Command{
		Use:   "run <task-file>",
		Short: "Run task(s) from a YAML file",
		Args:  cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			return runTasks(args[0], parallel, dryRun)
		},
	}

	cmd.Flags().IntVarP(&parallel, "parallel", "p", 3, "max concurrent executions")
	cmd.Flags().BoolVar(&dryRun, "dry-run", false, "validate without executing")

	return cmd
}

func runTasks(file string, parallel int, dryRun bool) error {
	tasks, err := task.ParseFile(file)
	if err != nil {
		return fmt.Errorf("parsing: %w", err)
	}

	// Validate all tasks.
	for i := range tasks {
		if err := task.Validate(&tasks[i]); err != nil {
			return fmt.Errorf("task %q: %w", tasks[i].Name, err)
		}
	}

	if dryRun {
		fmt.Printf("Validated %d task(s) successfully.\n", len(tasks))
		for _, t := range tasks {
			fmt.Printf("  - %s (model: %s, timeout: %v)\n", t.Name, t.Claude.Model, t.Timeout.Duration)
		}
		return nil
	}

	// Setup infrastructure.
	if err := cfg.EnsureDirs(); err != nil {
		return fmt.Errorf("creating dirs: %w", err)
	}

	store, err := storage.Open(cfg.DBPath)
	if err != nil {
		return fmt.Errorf("opening db: %w", err)
	}
	defer store.Close()

	level := slog.LevelInfo
	if verbose {
		level = slog.LevelDebug
	}
	logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: level}))

	runner := &executor.ClaudeRunner{
		BinaryPath: cfg.ClaudeBinaryPath,
		Logger:     logger,
		LogDir:     cfg.LogDir,
	}
	pool := executor.NewPool(parallel, runner, store, logger)

	// Handle graceful shutdown.
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	sigCh := make(chan os.Signal, 1)
	signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
	go func() {
		<-sigCh
		fmt.Fprintln(os.Stderr, "\nShutting down...")
		cancel()
	}()

	// Submit all tasks.
	fmt.Printf("Dispatching %d task(s) (max concurrency: %d)...\n", len(tasks), parallel)
	for i := range tasks {
		if err := store.CreateTask(&tasks[i]); err != nil {
			return fmt.Errorf("storing task: %w", err)
		}
		if err := store.UpdateTaskState(tasks[i].ID, task.StateQueued); err != nil {
			return fmt.Errorf("queuing task: %w", err)
		}
		tasks[i].State = task.StateQueued
		if err := pool.Submit(ctx, &tasks[i]); err != nil {
			logger.Warn("could not submit task", "name", tasks[i].Name, "error", err)
		}
	}

	// Wait for all results.
	completed, failed := 0, 0
	for i := 0; i < len(tasks); i++ {
		result := <-pool.Results()
		if result.Err != nil {
			failed++
			fmt.Printf("  FAIL  %s: %v\n", result.TaskID, result.Err)
		} else {
			completed++
			fmt.Printf("  OK    %s (cost: $%.4f)\n", result.TaskID, result.Execution.CostUSD)
		}
	}

	fmt.Printf("\nDone: %d completed, %d failed\n", completed, failed)
	if failed > 0 {
		return fmt.Errorf("%d task(s) failed", failed)
	}
	return nil
}