package main

// Verify Worker - BIP-340 Schnorr signature verification.
//
// Wire format:
//   supervisor -> worker: ["V_CHECK", reqID, evJSON]
//   worker -> supervisor: ["V_RESULT", reqID, 1|0]
//
// Pure compute: no IDB, no WebSocket, no signer access.
// Four instances run in parallel; the Verify Supervisor distributes round-robin.

import (
	"git.smesh.lol/smesh/web/common/helpers"
	"git.smesh.lol/smesh/web/common/jsbridge/verify"
	"git.smesh.lol/smesh/web/common/nostr"
	nosig "git.smesh.lol/smesh/web/common/nostr/sig"
)

func main() {
	verify.WorkerOnMessage(handleMessage)
}

func handleMessage(msg string) {
	w := newMW(msg)
	if w.str() != "V_CHECK" {
		return
	}
	reqID := w.num()
	evJSON := w.raw()

	ev := nostr.ParseEvent(evJSON)
	var valid int64
	if ev != nil && (*nosig.Event)(ev).CheckSig() {
		valid = 1
	}
	verify.WorkerPost(`["V_RESULT",` | helpers.Itoa(reqID) | `,` | helpers.Itoa(valid) | `]`)
}

// mw: minimal JSON-array walker

type mw struct {
	s string
	i int32
}

func newMW(s string) (v mw) {
	w := mw{s: s}
	for w.i < len(s) && s[w.i] != '[' {
		w.i++
	}
	if w.i < len(s) {
		w.i++
	}
	return w
}

func (w *mw) sep() {
	for w.i < len(w.s) {
		c := w.s[w.i]
		if c != ' ' && c != '\n' && c != '\r' && c != '\t' && c != ',' {
			break
		}
		w.i++
	}
}

func (w *mw) str() (s string) {
	w.sep()
	if w.i >= len(w.s) || w.s[w.i] != '"' {
		return ""
	}
	w.i++
	start := w.i
	for w.i < len(w.s) && w.s[w.i] != '"' {
		if w.s[w.i] == '\\' {
			w.i++
		}
		w.i++
	}
	if w.i >= len(w.s) {
		return ""
	}
	result := w.s[start:w.i]
	w.i++
	return result
}

func (w *mw) num() (n int64) {
	w.sep()
	neg := false
	if w.i < len(w.s) && w.s[w.i] == '-' {
		neg = true
		w.i++
	}
	var n int64
	for w.i < len(w.s) && w.s[w.i] >= '0' && w.s[w.i] <= '9' {
		n = n*10 + int64(w.s[w.i]-'0')
		w.i++
	}
	if neg {
		n = -n
	}
	return n
}

func (w *mw) raw() (s string) {
	w.sep()
	start := w.i
	w.i = skipval(w.s, w.i)
	if w.i < 0 {
		w.i = len(w.s)
		return ""
	}
	return w.s[start:w.i]
}

func skipval(s string, i int32) (n int32) {
	if i >= len(s) {
		return -1
	}
	c := s[i]
	if c == '"' {
		i++
		for i < len(s) && s[i] != '"' {
			if s[i] == '\\' {
				i++
			}
			i++
		}
		if i >= len(s) {
			return -1
		}
		return i + 1
	}
	if c == '{' || c == '[' {
		open := c
		close := byte('}')
		if open == '[' {
			close = ']'
		}
		depth := 1
		i++
		for i < len(s) && depth > 0 {
			if s[i] == '"' {
				i++
				for i < len(s) && s[i] != '"' {
					if s[i] == '\\' {
						i++
					}
					i++
				}
				if i >= len(s) {
					return -1
				}
				i++
				continue
			}
			if s[i] == open {
				depth++
			} else if s[i] == close {
				depth--
				if depth == 0 {
					return i + 1
				}
			}
			i++
		}
		return -1
	}
	for i < len(s) {
		c := s[i]
		if c == ',' || c == ']' || c == '}' {
			return i
		}
		i++
	}
	return i
}