package main

import (
	"flag"
	"fmt"
	"os"
	//"github.com/eschao/Config/cli"
)

type DBCli struct {
	Host     string `cli:"hostname database server hostname"`
	Port     string `cli:"port database server port"`
	User     string `cli:"user database username"`
	Password string `cli:"password database user password"`
}

func main() {

	countCommand := flag.NewFlagSet("count", flag.ExitOnError)
	listCommand := flag.NewFlagSet("list", flag.ExitOnError)

	// Count subcommand flag pointers
	// Adding a new choice for --metric of 'substring' and a new --substring flag
	countTextPtr := countCommand.String("text", "", "Text to parse. (Required)")
	countMetricPtr := countCommand.String("metric", "chars", "Metric {chars|words|lines|substring}. (Required)")
	countSubstringPtr := countCommand.String("substring", "", "The substring to be counted. Required for --metric=substring")
	countUniquePtr := countCommand.Bool("unique", false, "Measure unique values of a metric.")

	// List subcommand flag pointers
	listTextPtr := listCommand.String("text", "", "Text to parse. (Required)")
	listMetricPtr := listCommand.String("metric", "chars", "Metric <chars|words|lines>. (Required)")
	listUniquePtr := listCommand.Bool("unique", false, "Measure unique values of a metric.")

	// Verify that a subcommand has been provided
	// os.Arg[0] is the main command
	// os.Arg[1] will be the subcommand
	if len(os.Args) < 2 {
		//fmt.Println("list or count subcommand is required")
		flag.PrintDefaults()
		os.Exit(1)
	}

	// Switch on the subcommand
	// Parse the flags for appropriate FlagSet
	// FlagSet.Parse() requires a set of arguments to parse as input
	// os.Args[2:] will be all arguments starting after the subcommand at os.Args[1]
	switch os.Args[1] {
	case "list":
		listCommand.Parse(os.Args[2:])
	case "count":
		countCommand.Parse(os.Args[2:])
	default:
		flag.PrintDefaults()
		os.Exit(1)
	}

	// Check which subcommand was Parsed using the FlagSet.Parsed() function. Handle each case accordingly.
	// FlagSet.Parse() will evaluate to false if no flags were parsed (i.e. the user did not provide any flags)
	if listCommand.Parsed() {
		// Required Flags
		if *listTextPtr == "" {
			listCommand.PrintDefaults()
			os.Exit(1)
		}
		//Choice flag
		metricChoices := map[string]bool{"chars": true, "words": true, "lines": true}
		if _, validChoice := metricChoices[*listMetricPtr]; !validChoice {
			listCommand.PrintDefaults()
			os.Exit(1)
		}
		// Print
		fmt.Printf("textPtr: %s, metricPtr: %s, uniquePtr: %t\n", *listTextPtr, *listMetricPtr, *listUniquePtr)
	}

	if countCommand.Parsed() {
		// Required Flags
		if *countTextPtr == "" {
			countCommand.PrintDefaults()
			os.Exit(1)
		}
		// If the metric flag is substring, the substring flag is required
		if *countMetricPtr == "substring" && *countSubstringPtr == "" {
			countCommand.PrintDefaults()
			os.Exit(1)
		}
		//If the metric flag is not substring, the substring flag must not be used
		if *countMetricPtr != "substring" && *countSubstringPtr != "" {
			fmt.Println("--substring may only be used with --metric=substring.")
			countCommand.PrintDefaults()
			os.Exit(1)
		}
		//Choice flag
		metricChoices := map[string]bool{"chars": true, "words": true, "lines": true, "substring": true}
		if _, validChoice := metricChoices[*listMetricPtr]; !validChoice {
			countCommand.PrintDefaults()
			os.Exit(1)
		}
		//Print
		fmt.Printf("textPtr: %s, metricPtr: %s, substringPtr: %v, uniquePtr: %t\n", *countTextPtr, *countMetricPtr, *countSubstringPtr, *countUniquePtr)
	}
	/*
		config := DBCli{}
		root := cli.CliFlag{}
		err := cli.Parse(&config, &root)

		if err != nil {
			fmt.Printf("Can't parse cli. %s", err.Error())
		}
		flag.Parse()

		fmt.Printf("Host=%s\n", config.Host)
	*/

}