// ============================================================================
// PETITION — one signature per citizen, a wall in memory, not a clerk's eye
// ============================================================================
// In 2022 five Michigan governor candidates were struck from the ballot after
// an estimated 68,000 forged or duplicate petition lines; in 2004 the Nader
// petition in Pennsylvania collapsed the same way. Paid circulators duplicate
// names because the dedup is a spreadsheet applied weeks later. Here it is
// structural: a citizen's line count CANNOT exceed 1 — the memory refuses the
// write — and the clerk's certify/reject ruling is a terminal state that
// soma verify proves has no exit.
// ============================================================================

cell Petition {
    face {
        signal start_collection() -> Map
        signal sign(citizen: String) -> Map
        signal submit_to_clerk() -> Map
        signal clerk_ruling(threshold: Int) -> Map
        signal signature_total() -> Int
        signal phase() -> String
    }

    memory {
        // citizen -> petition lines. Two lines is unrepresentable.
        signed: Map<String, Int> [persistent, consistent]
        invariant signed >= 0 && signed <= 1
    }

    // certified and rejected have no outgoing edges: the ruling is forever.
    state drive {
        initial: drafting
        drafting -> collecting
        collecting -> submitted
        submitted -> certified
        submitted -> rejected
    }

    on phase() { return get_status("drive") }

    on start_collection() {
        let r = try { transition("drive", "collecting") }
        if r.error != () { return map("ok", false, "reason", "{r.error}") }
        return map("ok", true)
    }

    on sign(citizen: String) {
        if phase() != "collecting" {
            return map("ok", false, "reason", "window is {phase()}, not collecting")
        }
        let prior = signed.get(citizen) ?? 0
        let w = try { signed.set(citizen, prior + 1) }
        if w.error != () {
            return map("ok", false, "reason", "{citizen} already signed")
        }
        return map("ok", true, "total", signature_total())
    }

    on signature_total() {
        let names = signed.keys()
        let n = 0
        for c in names { n = n + (signed.get(c) ?? 0) }
        return n
    }

    on submit_to_clerk() {
        let r = try { transition("drive", "submitted") }
        if r.error != () { return map("ok", false, "reason", "{r.error}") }
        return map("ok", true, "signatures", signature_total())
    }

    on clerk_ruling(threshold: Int) {
        if phase() != "submitted" {
            return map("ok", false, "reason", "nothing submitted to rule on")
        }
        if signature_total() >= threshold { transition("drive", "certified") }
        if phase() == "submitted" { transition("drive", "rejected") }
        return map("ok", true, "ruling", phase())
    }
}

cell test PetitionTests {
    rules {
        assert sign("ada").ok == false                  // window not open yet
        assert start_collection().ok == true
        assert sign("ada").ok == true
        assert sign("bob").ok == true
        assert sign("ada").ok == false                  // duplicate bounces
        assert_fails signed.set("ada", 2)               // 2 lines: unrepresentable
        assert_fails signed.set("bob", -1)
        assert signature_total() == 2
        assert sign("eve").ok == true
        assert submit_to_clerk().ok == true
        assert sign("late").ok == false                 // window closed
        assert clerk_ruling(3).ok == true
        assert phase() == "certified"
        assert_fails transition("drive", "collecting")  // ruling is forever
        assert_fails transition("drive", "rejected")
    }
}