package cmd

import (
	"fmt"
	"os"
	"strings"

	"git.jnss.me/joakim/opal/internal/engine"
	"github.com/spf13/cobra"
)

var addCmd = &cobra.Command{
	Use:   "add <description> [modifiers...]",
	Short: "Add a new task",
	Long: `Add a new task with optional modifiers.

Examples:
  opal add buy groceries                          # No quotes needed!
  opal add review PR priority:H project:backend
  opal add buy groceries +shop carrots            # Tag can be anywhere
  opal add team meeting due:mon recur:1w +meetings`,
	Run: func(cmd *cobra.Command, args []string) {
		parsed := getParsedArgs(cmd)
		// For add, combine filters and modifiers (all are args to parse)
		allArgs := append(parsed.Filters, parsed.Modifiers...)
		if err := addTask(allArgs); err != nil {
			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
			os.Exit(1)
		}
	},
}

func addTask(args []string) error {
	// Parse description and modifiers from args
	// Description = all words that are NOT filters/modifiers
	// Filters/Modifiers = words with +, -, or containing :
	description, modifierArgs, err := parseAddArgs(args)
	if err != nil {
		return err
	}

	// Parse modifiers
	var mod *engine.Modifier

	if len(modifierArgs) > 0 {
		mod, err = engine.ParseModifier(modifierArgs)
		if err != nil {
			return fmt.Errorf("failed to parse modifiers: %w", err)
		}
	}

	// Check if this is a recurring task
	isRecurring := mod != nil && mod.SetAttributes["recur"] != nil

	if isRecurring {
		// Create recurring task (template + first instance)
		return addRecurringTask(description, mod)
	}

	// Create regular task
	task, err := engine.CreateTaskWithModifier(description, mod)
	if err != nil {
		return fmt.Errorf("failed to create task: %w", err)
	}

	fmt.Printf("Created task %s\n", task.UUID)
	if len(task.Tags) > 0 {
		fmt.Printf("Tags: %s\n", strings.Join(task.Tags, ", "))
	}

	return nil
}

// parseAddArgs extracts description and modifiers from args.
// Tags (+tag, -tag) are always modifiers. For key:value tokens, only
// recognized attribute keys (engine.ValidAttributeKeys) are treated as
// modifiers — everything else becomes part of the description.
func parseAddArgs(args []string) (string, []string, error) {
	var descParts []string
	var modifiers []string

	for _, arg := range args {
		if strings.HasPrefix(arg, "+") || strings.HasPrefix(arg, "-") {
			modifiers = append(modifiers, arg)
			continue
		}

		if idx := strings.Index(arg, ":"); idx > 0 {
			key := arg[:idx]
			if engine.ValidAttributeKeys[key] {
				modifiers = append(modifiers, arg)
				continue
			}
		}

		descParts = append(descParts, arg)
	}

	if len(descParts) == 0 {
		return "", nil, fmt.Errorf("description is required")
	}

	description := strings.Join(descParts, " ")
	return description, modifiers, nil
}

func addRecurringTask(description string, mod *engine.Modifier) error {
	instance, err := engine.CreateRecurringTask(description, mod)
	if err != nil {
		return err
	}

	fmt.Printf("Created recurring task %s\n", *instance.ParentUUID)
	fmt.Printf("First instance: %s\n", instance.UUID)

	return nil
}