package server

import (
	"regexp"
	"sort"
	"strings"

	"github.com/daniel/cursor-adapter/internal/types"
)

// Cowork-style mount path: /sessions/<adjective>-<adjective>-<color>/mnt/<folder>
// (and any deeper subpath; we capture only the mount root).
var mountPathRe = regexp.MustCompile(`/sessions/[a-z][a-z0-9]*(?:-[a-z][a-z0-9]*)+/mnt/[^\s/'"]+`)

// extractMountHints walks all prior tool_result blocks in the conversation
// and returns any Cowork-style /sessions/<id>/mnt/<folder> mount roots
// they reveal, deduped & sorted.
//
// This is purely stateless — we re-derive the set from the request body
// every turn. No server-side cache to invalidate, and it survives proxy
// restarts because the caller (Claude Desktop) replays the full history
// on each request anyway.
func extractMountHints(req types.AnthropicMessagesRequest) []string {
	seen := map[string]struct{}{}
	for _, m := range req.Messages {
		for _, b := range m.Content {
			if b.Type != "tool_result" {
				continue
			}
			for _, p := range mountPathRe.FindAllString(renderToolResultContent(b.Content), -1) {
				seen[p] = struct{}{}
			}
		}
	}
	if len(seen) == 0 {
		return nil
	}
	out := make([]string, 0, len(seen))
	for p := range seen {
		out = append(out, p)
	}
	sort.Strings(out)
	return out
}

// renderMountHints turns a list of mount roots into a prompt section the
// brain can refer to. Returns "" when there are no hints.
func renderMountHints(hints []string) string {
	if len(hints) == 0 {
		return ""
	}
	var b strings.Builder
	b.WriteString("Known host-mount paths (discovered earlier in this conversation, prefer these for any host file work):\n")
	for _, h := range hints {
		b.WriteString("- ")
		b.WriteString(h)
		b.WriteByte('\n')
	}
	return b.String()
}