package main

import (
	"fmt"
	"os"
	"slices"
)

func main() {
	if len(os.Args) == 1 || slices.Contains(os.Args, "-help") {
		printHelp()
		os.Exit(0)
	}

	var srcUser string
	var destUser string
	var password string
	var pdsUrl string
	var dryrun bool = false
	var verbose bool = false

	var importProfile bool = false
	var importFollows bool = false

	i := 1
	for {
		if i >= len(os.Args) { break }
		if os.Args[i][0] != '-' {
			fmt.Fprintf(os.Stderr, "unrecognised argument `%s`.\n", os.Args[i])
			os.Exit(1)
		}

		getValue := func(i int) (int, string) {
			if i + 1 >= len(os.Args) {
				fmt.Fprintf(os.Stderr, "-%s requires a value.\n", os.Args[i])
				os.Exit(1)
			}
			return i + 1, os.Args[i + 1]
		}

		switch os.Args[i][1:] {
		case "from":
			i, srcUser = getValue(i)
		case "to":
			i, destUser = getValue(i)
		case "pass":
			i, password = getValue(i)
		case "pds":
			i, pdsUrl = getValue(i)
		case "dryrun":
			dryrun = true
		case "v":
			verbose = true
		case "profile":
			importProfile = true
		case "follows":
			importFollows = true
		}
		i += 1
	}

	if srcUser == "" {
		fmt.Fprintf(os.Stderr, "missing required argument -from.\n")
		os.Exit(1)
	}
	if destUser == "" {
		fmt.Fprintf(os.Stderr, "missing required argument -to.\n")
		os.Exit(1)
	}
	if password == "" {
		fmt.Fprintf(os.Stderr, "missing required argument -pass.\n")
		os.Exit(1)
	}
	if pdsUrl == "" {
		fmt.Fprintf(os.Stderr, "missing required argument -pds.\n")
		os.Exit(1)
	}

	if !importProfile && !importFollows {
		fmt.Fprintf(os.Stderr, "no action was specified.\n")
		os.Exit(1)
	}

	session, err := CreateSession(pdsUrl, destUser, password)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to create session: %v\n", err)
		os.Exit(1)
	}

	if importProfile {
		err := ImportProfile(session, pdsUrl, srcUser, dryrun, verbose)
		if err != nil {
			fmt.Fprintf(os.Stderr, "failed to import profile: %v\n", err)
			os.Exit(1)
		}
	}
	if importFollows {
		err := ImportFollows(session, pdsUrl, srcUser, dryrun, verbose)
		if err != nil {
			fmt.Fprintf(os.Stderr, "failed to import follows: %v\n", err)
			os.Exit(1)
		}
	}
}

func printHelp() {
	fmt.Printf(
`usage: %s <arguments...> <imports...>

required arguments:
	-from <handle>: the account to import follow records from.
	-to <handle>: the account to import follow records to.
	-pass <password>: the password of the `+"`to`"+` account.
	-pds <pds-url>: the full https:// url of the `+"`to`"+` account's PDS.

imports (at least one required):
	-profile: imports the account profile, including avatar, banner, display name, and description.
	-follows: imports the following list of the account.

optional arguments:
	-dryrun: does not import follow records; good for sanity testing!
	-v: verbose output
	-help: shows this help message.
`,
	os.Args[0],
	)
}