package web

import (
	"net/url"
	"strings"

	"gitea.dooplex.hu/admin/felhom-controller/internal/infra"
)

// FileBrowser Quantum deep links (R-75).
//
// The template is taken VERBATIM from the shipped frontend router (SPIKE P2, read out of the
// bundle), not guessed:
//
//	function Ms(n,t,…){ … let a=q2(t), s=`/files/${encodeURIComponent(n)}${a}` … }
//	q2 = … .map(r=>encodeURIComponent(r)).join("/")        // per-SEGMENT encoding
//	function H2(n){ t=i.split("/")[2]; … }                 // source is the 3rd path segment
//
// So a link is constructible server-side from (sourceName, relPath) alone — no internal id, no
// index, no client-side state.
//
// A cold link (no FileBrowser session) is NOT lost: the router guard redirects to
// /login?redirect=<fullPath> and the login handler navigates back to it. The customer may still have
// to sign in, which is why the UI copy must not promise one click.

// fbSourceRoot is the FileBrowser origin for a customer domain. FileBrowser is published at
// files.<domain> by the base-infra traefik labels.
func fbSourceRoot(domain string) string {
	return "https://files." + domain
}

// fileBrowserLink builds a deep link into a named FileBrowser source at relPath.
//
// ENCODING TRAP, measured in SPIKE P2 — use url.PathEscape, NEVER url.QueryEscape:
//
//	"Média & könyvtár"  PathEscape=M%C3%A9dia%20&%20k%C3%B6nyvt%C3%A1r   QueryEscape=M%C3%A9dia+%26+k%C3%B6nyvt%C3%A1r
//	"a+b"               PathEscape=a+b                                   QueryEscape=a%2Bb
//
// QueryEscape encodes a space as "+", which inside a PATH segment means a literal plus and breaks
// the link. PathEscape leaves "&" unescaped, which is correct here: "&" is a legal path sub-delim,
// and html/template escapes it to "&amp;" in the href attribute, which the browser decodes back to
// "&". The two escapings compose — so do NOT pre-escape for HTML here.
//
// Source names cannot contain "/" (they come from filepath.Base or the ASCII import constant), which
// is what keeps the router's split("/")[2] round-trip intact.
func fileBrowserLink(domain, sourceName, relPath string) string {
	var b strings.Builder
	b.WriteString(fbSourceRoot(domain))
	b.WriteString("/files/")
	b.WriteString(url.PathEscape(sourceName))
	for _, seg := range strings.Split(strings.Trim(relPath, "/"), "/") {
		if seg == "" {
			continue
		}
		b.WriteString("/")
		b.WriteString(url.PathEscape(seg))
	}
	return b.String()
}

// importFolderLink is the deep link to a drop-zone app's folder inside the canonical import source.
func importFolderLink(domain, appDir string) string {
	return fileBrowserLink(domain, infra.FileBrowserImportLabel, appDir)
}