package setup

import (
	"fmt"
	"strings"

	"github.com/charmbracelet/huh"
	"github.com/charmbracelet/huh/spinner"

	"github.com/hachem-wtf/benson/internal/config"
	"github.com/hachem-wtf/benson/internal/modrinth"
)

func pickMods(existing []config.Mod, mc, loader string) []config.Mod {
	mods := append([]config.Mod{}, existing...)
	client := modrinth.NewClient()

	for {
		options := []huh.Option[string]{huh.NewOption("Search & add a mod", "add")}
		if len(mods) > 0 {
			options = append(options, huh.NewOption("Remove a mod", "remove"))
		}
		options = append(options, huh.NewOption("Done", "done"))

		var action string
		menu := huh.NewSelect[string]().
			Title(fmt.Sprintf("Mods · %d configured", len(mods))).
			Description(modsSummary(mods)).
			Options(options...).
			Value(&action)

		if err := runSub(menu); err != nil {
			return mods
		}

		switch action {
		case "done":
			return mods
		case "add":
			mods = addMod(mods, client, mc, loader)
		case "remove":
			mods = removeMod(mods)
		}
	}
}

func addMod(mods []config.Mod, client *modrinth.Client, mc, loader string) []config.Mod {
	var query string
	if err := runSub(huh.NewInput().Title("Search Modrinth").Description("Mod name or keyword").Value(&query)); err != nil {
		return mods
	}
	query = strings.TrimSpace(query)
	if query == "" {
		return mods
	}

	var hits []modrinth.SearchHit
	_ = spinner.New().Title("Searching Modrinth…").Action(func() {
		hits, _ = client.Search(query, mc, loader)
	}).Run()

	if len(hits) == 0 {
		_ = runSub(huh.NewNote().Title("No results").Description("Nothing matched “" + query + "” for MC " + mc + "."))
		return mods
	}

	options := make([]huh.Option[string], len(hits))
	for i, h := range hits {
		options[i] = huh.NewOption(fmt.Sprintf("%s  (%s)", h.Title, h.Slug), h.Slug)
	}

	var slug string
	if err := runSub(huh.NewSelect[string]().Title("Results for “" + query + "”").Options(options...).Height(selectHeight(len(options))).Value(&slug)); err != nil {
		return mods
	}
	if slug == "" {
		return mods
	}

	return upsertMod(mods, config.Mod{Slug: slug, Version: pickVersion(client, slug, mc, loader)})
}

func pickVersion(client *modrinth.Client, slug, mc, loader string) string {
	var versions []modrinth.Version
	_ = spinner.New().Title("Loading versions…").Action(func() {
		versions, _ = client.GetVersions(slug)
	}).Run()

	options := []huh.Option[string]{huh.NewOption("Latest compatible  ·  recommended", "")}
	for _, v := range versions {
		if compatibleWith(v, mc, loader) {
			options = append(options, huh.NewOption(v.VersionNumber, v.VersionNumber))
		}
	}

	var chosen string
	_ = runSub(huh.NewSelect[string]().
		Title("Version for " + slug).
		Description("Keep it on latest, or pin a specific version").
		Options(options...).
		Height(selectHeight(len(options))).
		Value(&chosen))
	return chosen
}

func removeMod(mods []config.Mod) []config.Mod {
	options := make([]huh.Option[string], len(mods))
	for i, m := range mods {
		options[i] = huh.NewOption(modLabel(m), m.Slug)
	}

	var slug string
	if err := runSub(huh.NewSelect[string]().Title("Remove which mod?").Options(options...).Height(selectHeight(len(options))).Value(&slug)); err != nil {
		return mods
	}
	if slug == "" {
		return mods
	}

	kept := make([]config.Mod, 0, len(mods))
	for _, m := range mods {
		if m.Slug != slug {
			kept = append(kept, m)
		}
	}
	return kept
}

func runSub(field huh.Field) error {
	return huh.NewForm(huh.NewGroup(field)).WithTheme(emberTheme()).Run()
}

func upsertMod(mods []config.Mod, mod config.Mod) []config.Mod {
	for i := range mods {
		if mods[i].Slug == mod.Slug {
			mods[i] = mod
			return mods
		}
	}
	return append(mods, mod)
}

func compatibleWith(v modrinth.Version, mc, loader string) bool {
	hasMC, hasLoader := false, false
	for _, g := range v.GameVersions {
		if g == mc {
			hasMC = true
			break
		}
	}
	for _, l := range v.Loaders {
		if l == loader {
			hasLoader = true
			break
		}
	}
	return hasMC && hasLoader
}

func modLabel(m config.Mod) string {
	if m.Pinned() {
		return m.Slug + "  (" + m.Version + ")"
	}
	return m.Slug + "  (latest)"
}

func modsSummary(mods []config.Mod) string {
	if len(mods) == 0 {
		return "No mods yet — search Modrinth to add some."
	}

	var b strings.Builder
	for _, m := range mods {
		fmt.Fprintf(&b, "• %s\n", modLabel(m))
	}
	return strings.TrimRight(b.String(), "\n")
}