//! Human given names for minted agents.
//!
//! A team used to come back as `planner`, `coder`, `tester`, `reviewer`,
//! `committer` — the roster read as a list of job tickets, and the UI showed
//! the same word twice (name on top, role underneath). A crew you keep should
//! read like people: Meredith, Vijay, Tomasz, Amara.
//!
//! The role is not lost — it stays in `job_title`, which is what the mission
//! machinery binds on. Only the display identity changes.
//!
//! Names are drawn from many naming traditions on purpose: this workforce is
//! not from one place. They are given names only — no surnames — so nobody
//! reads a claw as a specific real person.

/// Given names, deliberately wide. Kept as one flat list rather than grouped by
/// origin: grouping invites picking "one from each", which is a worse kind of
/// tokenism than simply having a broad pool and drawing from it evenly.
///
/// Size is a product decision, not an aesthetic one. Every mission now mints
/// its own crew and nothing retires them, so the roster grows by the team size
/// per mission — at ~5 a mission a 70-name pool starts emitting "Amara 2"
/// inside twenty missions. This pool carries a few hundred so a workspace runs
/// for a long time before any name repeats at all.
pub const NAMES: &[&str] = &[
    // A
    "Aarav", "Abebe", "Adaora", "Adrian", "Agnieszka", "Ahmad", "Aiko", "Ainhoa", "Alejandro",
    "Alina", "Amara", "Amina", "Anders", "Andrea", "Anjali", "Annika", "Antoine", "Arjun", "Astrid",
    "Ayo", "Ayesha", "Aziz",
    // B–C
    "Beatriz", "Bilal", "Bjorn", "Blessing", "Bogdan", "Camila", "Carlos", "Catalina", "Chidi",
    "Chiara", "Chioma", "Cyrus",
    // D–E
    "Dagny", "Damir", "Daniela", "Dilnoza", "Dmitri", "Ebele", "Eduardo", "Eero", "Ekaterina",
    "Elena", "Elias", "Emeka", "Enrique", "Esi", "Esther", "Eun-ji", "Ewa",
    // F–G
    "Fabio", "Farida", "Fatou", "Felipe", "Fernanda", "Freya", "Gabriel", "Georgi", "Giulia",
    "Grace", "Gunnar", "Gulnara",
    // H–I
    "Hana", "Hasan", "Heidi", "Hina", "Hiroshi", "Ibrahim", "Idris", "Ilya", "Imani", "Ingrid",
    "Iris", "Isabela", "Ivan", "Iwona",
    // J–K
    "Jaromir", "Javier", "Jing", "Joana", "Johan", "Josefina", "Junko", "Kaito", "Kalinda", "Karim",
    "Katarzyna", "Kenji", "Khalid", "Kiran", "Klara", "Kwame", "Kyoko",
    // L–M
    "Lakshmi", "Lars", "Laila", "Leilani", "Lena", "Liam", "Linnea", "Lucia", "Lukas", "Madhavi",
    "Maja", "Malik", "Marisol", "Mateo", "Matteo", "Mei", "Meredith", "Milena", "Mira", "Mohan",
    "Mira-Lynn", "Mateusz",
    // N–O
    "Nadia", "Nasrin", "Neelam", "Niamh", "Nikolai", "Nilufar", "Nkechi", "Noor", "Nuria", "Oksana",
    "Oleksii", "Olamide", "Omar", "Oskar", "Osei",
    // P–R
    "Paloma", "Panagiotis", "Pedro", "Petra", "Priya", "Rafael", "Rania", "Ravi", "Reza", "Renata",
    "Rin", "Robert", "Rosalind", "Rustam",
    // S
    "Sadia", "Salome", "Samir", "Sanjay", "Sara", "Seong-min", "Sipho", "Sofia", "Solveig", "Soren",
    "Suvi", "Svetlana",
    // T–U
    "Tadeusz", "Takeshi", "Tamar", "Tariq", "Thandiwe", "Thi", "Tim", "Tomasz", "Tove", "Tuva",
    "Ulrika", "Uma", "Usman",
    // V–Z
    "Valentina", "Vera", "Vijay", "Vikram", "Wanjiru", "Wei", "Wiktor", "Yara", "Yasmin", "Yohannes",
    "Yuki", "Yusuf", "Zainab", "Zara", "Zoltan", "Zuzanna",
];

/// Pick a name not already in `taken`.
///
/// `seed` spreads the starting point so a workspace does not always begin at
/// "Amara" — it is an offset into the list, not randomness, so the choice is
/// reproducible for a given (seed, taken) pair and therefore testable.
///
/// When every name is taken it appends a numeric suffix — `Amara 2` — rather
/// than returning `None` and forcing the caller to invent something. Running
/// out is a nice problem (70+ concurrent agents in one workspace) and a
/// duplicate display name is far less harmful than a failed mission launch.
pub fn pick(taken: &[String], seed: u64) -> String {
    let start = (seed % NAMES.len() as u64) as usize;
    for i in 0..NAMES.len() {
        let candidate = NAMES[(start + i) % NAMES.len()];
        if !taken.iter().any(|t| t.eq_ignore_ascii_case(candidate)) {
            return candidate.to_string();
        }
    }
    // Second pass with a suffix. `round` starts at 2 so the first repeat reads
    // "Amara 2", which is how a person would disambiguate two colleagues.
    for round in 2..1000 {
        for i in 0..NAMES.len() {
            let candidate = format!("{} {}", NAMES[(start + i) % NAMES.len()], round);
            if !taken.iter().any(|t| t.eq_ignore_ascii_case(&candidate)) {
                return candidate;
            }
        }
    }
    // Unreachable in practice; still not a panic.
    format!("Agent {seed}")
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn names_are_unique_and_non_empty() {
        let mut seen = std::collections::HashSet::new();
        for n in NAMES {
            assert!(!n.trim().is_empty(), "empty name in the pool");
            assert!(seen.insert(n.to_ascii_lowercase()), "duplicate in pool: {n}");
        }
        // Every mission mints its own crew and nothing retires them, so the
        // pool is consumed for the life of the workspace, not recycled. At ~5
        // per mission this is ~35 missions before the first numeric suffix.
        assert!(NAMES.len() >= 150, "pool too small for one crew per mission");
    }

    /// A crew should not read as an alphabetical run.
    ///
    /// With the role index as the seed, every crew started at the top of the
    /// pool and took the next free names — the first real mission hired Aarav,
    /// Abebe, Adaora, Adrian, Agnieszka. Unique and correct, and obviously
    /// generated. Callers now seed from the claw's uuid tail, so this checks
    /// that well-spread seeds actually land in different regions of the pool
    /// rather than clustering at one end.
    #[test]
    fn spread_seeds_do_not_produce_an_alphabetical_run() {
        let index_of = |n: &str| NAMES.iter().position(|c| *c == n).expect("name in pool");
        let seeds = [
            0x9e37_79b9_7f4a_7c15u64,
            0x1234_5678_9abc_def0,
            0xfeed_face_dead_beef,
            0x0f0f_0f0f_f0f0_f0f0,
            0xa5a5_5a5a_c3c3_3c3c,
        ];
        let mut taken: Vec<String> = Vec::new();
        let mut positions = Vec::new();
        for s in seeds {
            let n = pick(&taken, s);
            positions.push(index_of(&n) as i64);
            taken.push(n);
        }
        // Adjacent picks landing within a couple of slots of each other is the
        // clustering signature; require the crew to span a real distance.
        let (min, max) = (
            *positions.iter().min().unwrap(),
            *positions.iter().max().unwrap(),
        );
        assert!(
            max - min > (NAMES.len() as i64) / 3,
            "crew clustered in one region of the pool: {positions:?}"
        );
    }

    /// The scenario the operator actually asked for: consecutive missions must
    /// not hand back the same names. Reuse is off, so mission two staffs from
    /// what mission one left.
    #[test]
    fn consecutive_missions_get_different_crews() {
        let mut roster: Vec<String> = Vec::new();
        let mut crews: Vec<Vec<String>> = Vec::new();
        for mission in 0..6u64 {
            let mut crew = Vec::new();
            for role in 0..5u64 {
                let n = pick(&roster, mission * 5 + role);
                roster.push(n.clone());
                crew.push(n);
            }
            crews.push(crew);
        }
        for (i, a) in crews.iter().enumerate() {
            for (j, b) in crews.iter().enumerate().skip(i + 1) {
                let shared: Vec<_> = a.iter().filter(|n| b.contains(n)).collect();
                assert!(
                    shared.is_empty(),
                    "missions {i} and {j} share {shared:?} — crews must be distinct"
                );
            }
        }
        // And no duplicates anywhere on the roster.
        let uniq: std::collections::HashSet<_> = roster.iter().collect();
        assert_eq!(uniq.len(), roster.len(), "a name was issued twice");
    }

    #[test]
    fn pick_avoids_taken_names() {
        let taken: Vec<String> = NAMES.iter().take(10).map(|s| s.to_string()).collect();
        let got = pick(&taken, 0);
        assert!(
            !taken.iter().any(|t| t.eq_ignore_ascii_case(&got)),
            "picked a name already taken: {got}"
        );
    }

    #[test]
    fn pick_is_case_insensitive_about_taken() {
        // A name already on the roster in a different case is still taken —
        // "meredith" and "Meredith" are the same colleague.
        let taken = vec![NAMES[0].to_ascii_lowercase()];
        assert_ne!(pick(&taken, 0).to_ascii_lowercase(), taken[0]);
    }

    #[test]
    fn seed_spreads_the_starting_point() {
        // Different seeds should not all hand back the same first name, or a
        // fresh workspace always opens with the same roster.
        let a = pick(&[], 0);
        let b = pick(&[], 7);
        assert_ne!(a, b, "seed had no effect on the choice");
    }

    #[test]
    fn exhausting_the_pool_suffixes_rather_than_failing() {
        let taken: Vec<String> = NAMES.iter().map(|s| s.to_string()).collect();
        let got = pick(&taken, 0);
        assert!(
            !taken.iter().any(|t| t.eq_ignore_ascii_case(&got)),
            "must not reuse a taken name"
        );
        assert!(got.ends_with(" 2"), "expected a suffixed name, got {got}");
    }

    #[test]
    fn a_full_team_gets_distinct_names() {
        // The actual scenario: mint five roles into an empty workspace and get
        // five different people, not five "planner"s.
        let mut taken: Vec<String> = Vec::new();
        for i in 0..5 {
            let n = pick(&taken, i);
            assert!(!taken.contains(&n), "repeated {n} within one team");
            taken.push(n);
        }
        assert_eq!(taken.len(), 5);
    }
}