package link

import (
	"context"
	"downloadhub/pkg/data"
	"flag"
	"fmt"
	"os"
	"strings"

	"github.com/google/subcommands"
)

type (
	LinkCmd struct {
		os   string
		arch string
		out  string
	}
)

func (*LinkCmd) Name() string     { return "link" }
func (*LinkCmd) Synopsis() string { return "add/edit/remove a download link" }
func (*LinkCmd) Usage() string {
	return `Usage: ./cli link ACTION LINK SLUG

Actions: add, edit, rm

Options:
`
}

func (p *LinkCmd) SetFlags(f *flag.FlagSet) {
	f.StringVar(&p.os, "os", "", "set the operating system")
	f.StringVar(&p.arch, "architecture", "", "set the instruction set")
	f.StringVar(&p.out, "out", "./config.json", "path to the configuration file")
}

func (p *LinkCmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
	if f.NArg() != 3 {
		fmt.Fprintln(os.Stderr, "error: bad usage")
		return subcommands.ExitUsageError
	}

	switch strings.ToLower(f.Arg(0)) {
	case "add":
		return p.add(f.Arg(1), f.Arg(2))
	case "edit":
		return p.edit(f.Arg(1), f.Arg(2))
	case "rm":
		return p.rm(f.Arg(1), f.Arg(2))
	default:
		{
			fmt.Fprintln(os.Stderr, "error: unknown command")
			return subcommands.ExitUsageError
		}
	}
}

func (p *LinkCmd) add(link, slug string) subcommands.ExitStatus {
	d, err := data.Load(p.out)
	if err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		return subcommands.ExitFailure
	}

	var found bool
	for i, soft := range d.Softwares {
		if soft.Slug == slug {
			if exists(link, soft) {
				fmt.Fprintln(os.Stderr, "error: link already exists")
				return subcommands.ExitFailure
			}
			soft.DownloadLinks = append(soft.DownloadLinks, data.DownloadLink{
				OS:   p.os,
				Arch: p.arch,
				URL:  link,
			})
			d.Softwares[i] = soft
			found = true
			break
		}
	}

	if !found {
		fmt.Fprintf(os.Stderr, "error: slug '%s' cannot be found\n", slug)
		return subcommands.ExitFailure
	}

	if err := data.Save(d, p.out); err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		return subcommands.ExitFailure
	}
	return subcommands.ExitSuccess
}

func (p *LinkCmd) edit(link, slug string) subcommands.ExitStatus {
	d, err := data.Load(p.out)
	if err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		return subcommands.ExitFailure
	}

	var foundSlug, foundLink bool
	for i, soft := range d.Softwares {
		if soft.Slug == slug {
			for y, l := range soft.DownloadLinks {
				if l.URL == link {
					if len(p.os) > 0 {
						l.OS = p.os
					}

					if len(p.os) > 0 {
						l.Arch = p.arch
					}

					soft.DownloadLinks[y] = l
					foundLink = true
					break
				}
			}
			d.Softwares[i] = soft
			foundSlug = true
			break
		}
	}

	if !foundSlug {
		fmt.Fprintf(os.Stderr, "error: slug '%s' cannot be found\n", slug)
		return subcommands.ExitFailure
	}

	if !foundLink {
		fmt.Fprintf(os.Stderr, "error: link '%s' cannot be found\n", link)
		return subcommands.ExitFailure
	}

	if err := data.Save(d, p.out); err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		return subcommands.ExitFailure
	}
	return subcommands.ExitSuccess
}

func (p *LinkCmd) rm(link, slug string) subcommands.ExitStatus {
	d, err := data.Load(p.out)
	if err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		return subcommands.ExitFailure
	}

	var foundSlug, foundLink bool
	for i, soft := range d.Softwares {
		if soft.Slug == slug {
			var index int
			for y, l := range soft.DownloadLinks {
				if l.URL == link {
					index = y
					foundLink = true
					break
				}
			}
			if foundLink {
				soft.DownloadLinks = append(soft.DownloadLinks[:index], soft.DownloadLinks[index+1:]...)
			}
			d.Softwares[i] = soft
			foundSlug = true
			break
		}
	}

	if !foundSlug {
		fmt.Fprintf(os.Stderr, "error: slug '%s' cannot be found\n", slug)
		return subcommands.ExitFailure
	}

	if !foundLink {
		fmt.Fprintf(os.Stderr, "error: link '%s' cannot be found\n", link)
		return subcommands.ExitFailure
	}

	if err := data.Save(d, p.out); err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		return subcommands.ExitFailure
	}
	return subcommands.ExitSuccess
}

func exists(link string, soft data.Software) bool {
	for _, l := range soft.DownloadLinks {
		if l.URL == link {
			return true
		}
	}
	return false
}