package main

import (
	"errors"
	"io"
	"net/url"
	"os"
	"strconv"
	"strings"

	"git.sr.ht/~adnano/go-gemini"
)

type Command func(b *Browser, args ...string) error

var commands = map[string]Command{
	"prompt": func(b *Browser, args ...string) error {
		b.CommandMode()
		prompt := strings.Join(args, " ")
		b.input.SetInput(prompt)
		return nil
	},
	"follow": func(b *Browser, args ...string) error {
		return b.FollowMode()
	},
	"open": func(b *Browser, args ...string) error {
		if len(args) == 0 {
			return errors.New("usage: open <url>")
		}

		rawurl := args[0]
		u, err := url.Parse(rawurl)
		if err != nil {
			return err
		}

		if len(u.Scheme) == 0 && len(u.Host) == 0 {
			u2, err := url.Parse("gemini://" + rawurl)
			if err == nil {
				u = u2
			}
		}
		b.tabs[b.tab].DoBackground(&gemini.Request{URL: u})
		return nil
	},
	"close": func(b *Browser, args ...string) error {
		b.CloseTab(b.tab)
		return nil
	},
	"newtab": func(b *Browser, args ...string) error {
		tab := b.NewTab()
		b.tab++
		b.InsertTab(b.tab, tab)
		tab.Do(&gemini.Request{
			URL: &url.URL{
				Scheme: "about",
				Host:   "newtab",
			},
		})
		b.makeTabVisible()
		return nil
	},
	"clone": func(b *Browser, args ...string) error {
		t := b.tabs[b.tab]
		clone := t.Clone()
		b.tab++
		b.InsertTab(b.tab, clone)
		clone.Reload()
		b.makeTabVisible()
		return nil
	},
	"reload": func(b *Browser, args ...string) error {
		b.tabs[b.tab].Reload()
		return nil
	},
	"cancel": func(b *Browser, args ...string) error {
		b.tabs[b.tab].Cancel()
		return nil
	},
	"back": func(b *Browser, args ...string) error {
		tab := b.tabs[b.tab]
		if !tab.Back() {
			b.Message("Already at beginning of history")
		}
		return nil
	},
	"forward": func(b *Browser, args ...string) error {
		tab := b.tabs[b.tab]
		if !tab.Forward() {
			b.Message("Already at end of history")
		}
		return nil
	},
	"previous": func(b *Browser, args ...string) error {
		b.Previous()
		return nil
	},
	"next": func(b *Browser, args ...string) error {
		b.Next()
		return nil
	},
	"quit": func(b *Browser, args ...string) error {
		b.view.Exit()
		return nil
	},
	"scroll": func(b *Browser, args ...string) error {
		const usage = "usage: scroll <n>[%]"
		if len(args) == 0 {
			return errors.New(usage)
		}
		amount := args[0]
		switch amount {
		case "top":
			b.tabView.Top()
			b.tabView.Invalidate()
		case "bottom":
			b.tabView.Bottom()
			b.tabView.Invalidate()
		default:
			var scroll int
			if strings.HasSuffix(amount, "%") {
				percent, err := strconv.Atoi(amount[:len(amount)-1])
				if err != nil {
					return errors.New(usage)
				}
				_, h := b.tabView.Size()
				scroll = h * percent / 100
			} else {
				var err error
				scroll, err = strconv.Atoi(amount)
				if err != nil {
					return errors.New(usage)
				}
			}
			b.tabView.ScrollDown(scroll)
			b.tabView.Invalidate()
		}
		return nil
	},
	"save": func(b *Browser, args ...string) error {
		if len(args) == 0 {
			return errors.New("usage: save <path>")
		}
		tab := b.tabs[b.tab]
		f, err := os.Create(args[0])
		if err != nil {
			return err
		}
		defer f.Close()
		io.Copy(f, &tab.buf)
		return nil
	},
	"bookmark": func(b *Browser, args ...string) error {
		tab := b.tabs[b.tab]
		if b.bookmarks.Add(gemini.LineLink{
			URL:  tab.URL(),
			Name: tab.Title(),
		}) {
			b.Message("Bookmarked")
		} else {
			b.Message("Already bookmarked")
		}
		return nil
	},
	"search": func(b *Browser, args ...string) error {
		if len(args) == 0 {
			return errors.New("usage: search <query...>")
		}
		u := b.config.Search.URL.ResolveReference(&url.URL{
			RawQuery: gemini.QueryEscape(strings.Join(args, " ")),
		})
		b.tabs[b.tab].DoBackground(&gemini.Request{URL: u})
		return nil
	},
}