//! Command-line arguments, `orrery names`, `ship`, `weapons`, `armour`,
//! `galaxy`, `system` and `town`.

use std::collections::HashMap;

use crate::dungeon::Pos;
use crate::dungeon::crawl::Crawl;
use crate::dungeon::{armour, arms};
use crate::items::Item;
use crate::names::{self, Culture};
use crate::scenes::derelict::tile_look;
use crate::scenes::inventory::look;
use crate::seed;
use crate::space::Vec2;
use crate::space::galaxy::{self, HALF_HEIGHT, HALF_WIDTH};
use crate::space::system::{Landing, PlaceKind, SystemKind};
use crate::space::{orbit, survey};
use crate::{scenes, town};

pub const USAGE: &str = "\
usage: orrery [--seed N]
       orrery names [--culture NAME] [-n COUNT] [--seed N]
       orrery ship [-n WHICH] [--seed N]
       orrery weapons [-n COUNT] [--seed N]
       orrery armour [-n COUNT] [--seed N]
       orrery galaxy [--seed N]
       orrery system [-n WHICH] [--seed N]
       orrery town [-n WHICH] [--inside] [--seed N]

  --seed N        universe seed; the same seed always makes the same universe.
                  To play, without it you carry on as whoever you last played;
                  with it, you make a new character in that universe
  names           print generated names instead of playing
  --culture NAME  qaari, cant, houses or drift (default: all four)
  -n COUNT        how many of each kind to print (default: 8)
  ship            print a whole derelict, as you'd find it on boarding
  -n WHICH        which derelict: the first you'd board, the second... (default: 1)
  weapons         print weapons as you might find them aboard wrecks
  -n COUNT        how many (default: 12)
  armour          print armour as you might find it aboard wrecks
  -n COUNT        how many (default: 12)
  galaxy          print the star map: every system, its lanes and who holds it
  system          print a star system: orbits, moons, places
  -n WHICH        which system, numbered as `galaxy` lists them (default: the
                  one the universe started in)
  town            print a capital city in the system you start in
  -n WHICH        which capital: the homeworld's is 1, then outwards (default: 1)
  --inside        print the inside of one building of each kind, too
";

pub enum Command {
    Play { seed: Option<u64> },
    Names(NamesOpts),
    Ship { seed: u64, which: u64 },
    Weapons { seed: u64, count: usize },
    Armour { seed: u64, count: usize },
    Galaxy { seed: u64 },
    System { seed: u64, which: Option<u64> },
    Town { seed: u64, which: u64, inside: bool },
    Help,
}

pub struct NamesOpts {
    pub cultures: Vec<Culture>,
    pub count: usize,
    pub seed: u64,
}

pub fn parse(args: &[String]) -> Result<Command, String> {
    let mut args = args.iter().map(String::as_str).peekable();
    let sub = args.next_if(|a| {
        matches!(*a, "names" | "ship" | "weapons" | "armour" | "galaxy" | "system" | "town")
    });
    let (mut seed, mut culture, mut count, mut inside) = (None, None, None, false);
    while let Some(arg) = args.next() {
        match arg {
            "-h" | "--help" => return Ok(Command::Help),
            "--seed" => seed = Some(number(args.next(), "--seed")?),
            "--inside" if sub == Some("town") => inside = true,
            "-n" if matches!(
                sub,
                Some("names" | "ship" | "weapons" | "armour" | "system" | "town")
            ) =>
            {
                count = Some(number(args.next(), "-n")?)
            }
            "--culture" if sub == Some("names") => {
                let name = args.next().ok_or("--culture needs a value")?;
                culture = Some(Culture::parse(name).ok_or(format!("no culture called {name:?}"))?);
            }
            other => return Err(format!("unexpected argument {other:?}")),
        }
    }
    match sub {
        None => Ok(Command::Play { seed }),
        Some("ship") => Ok(Command::Ship {
            seed: seed.unwrap_or_else(seed::from_clock),
            which: count.unwrap_or(1),
        }),
        Some("weapons") => Ok(Command::Weapons {
            seed: seed.unwrap_or_else(seed::from_clock),
            count: count.unwrap_or(12) as usize,
        }),
        Some("armour") => Ok(Command::Armour {
            seed: seed.unwrap_or_else(seed::from_clock),
            count: count.unwrap_or(12) as usize,
        }),
        Some("galaxy") => Ok(Command::Galaxy { seed: seed.unwrap_or_else(seed::from_clock) }),
        Some("system") => {
            Ok(Command::System { seed: seed.unwrap_or_else(seed::from_clock), which: count })
        }
        Some("town") => Ok(Command::Town {
            seed: seed.unwrap_or_else(seed::from_clock),
            which: count.unwrap_or(1),
            inside,
        }),
        _ => Ok(Command::Names(NamesOpts {
            cultures: culture.map_or(Culture::ALL.to_vec(), |c| vec![c]),
            count: count.unwrap_or(8) as usize,
            seed: seed.unwrap_or_else(seed::from_clock),
        })),
    }
}

/// Prints the `which`th derelict you'd board in universe `seed`, everything
/// on it revealed.
pub fn print_ship(seed: u64, which: u64) {
    let crawl = Crawl::new(seed::derive(seed, "derelict", which));
    let map = &crawl.map;
    println!(
        "{}, a derelict {}  (universe {seed}, derelict {which})\n",
        crawl.name, crawl.description
    );
    for y in 0..map.height {
        let row: String = (0..map.width)
            .map(|x| {
                let p = Pos::new(x, y);
                if p == crawl.player {
                    '@'
                } else if let Some(m) = crawl.monster_at(p) {
                    m.kind.glyph
                } else if let Some(l) = crawl.loot_at(p) {
                    look(&l.stack.item).0
                } else {
                    tile_look(map.tile(p)).0
                }
            })
            .collect();
        println!("{}", row.trim_end());
    }
    let mut rooms: Vec<&str> = map.rooms.iter().map(|r| r.name).collect();
    rooms.sort_unstable();
    rooms.dedup();
    println!(
        "\n@ you  Θ airlock  + door  * artifact  ( salvage  ! medpatch  ) weapon  }} gun  [ armor  % food"
    );
    println!(
        "monsters: {}",
        crawl.monsters.iter().map(|m| m.kind.name).collect::<Vec<_>>().join(", ")
    );
    let weapons: Vec<String> = crawl
        .loot
        .iter()
        .filter_map(|l| match &l.stack.item {
            Item::Weapon(w) => Some(format!("{} ({})", w.name(), w.damage_text())),
            _ => None,
        })
        .collect();
    println!("weapons: {}", weapons.join(", "));
    let armour: Vec<String> = crawl
        .loot
        .iter()
        .filter_map(|l| match &l.stack.item {
            Item::Armor(a) => Some(format!("{} ({})", a.name(), a.guards_text())),
            _ => None,
        })
        .collect();
    println!("armour: {}", armour.join(", "));
    println!("rooms: {}", rooms.join(", "));
}

/// Prints `count` weapons as you might find them aboard wrecks in universe
/// `seed`, for tuning the tables in `dungeon::arms`.
pub fn print_weapons(seed: u64, count: usize) {
    print!("{}", arms::catalogue(&mut seed::rng(seed::derive(seed, "catalogue", 0)), count));
}

/// Prints `count` pieces of armour as you might find them aboard wrecks in
/// universe `seed`, for tuning the tables in `dungeon::armour`.
pub fn print_armour(seed: u64, count: usize) {
    let mut rng = seed::rng(seed::derive(seed, "armour catalogue", 0));
    print!("{}", armour::catalogue(&mut rng, count));
}

/// Prints the galaxy of universe `seed`: a map, then every system by who
/// holds it, numbered for `orrery system -n`.
pub fn print_galaxy(seed: u64) {
    let g = galaxy::generate(seed);
    // Two light-years to a column, four to a row, so it fits a terminal.
    let (cols, rows) = ((HALF_WIDTH * 1.2) as usize, (HALF_HEIGHT * 0.6) as usize);
    let cell = |p: Vec2| {
        let col = ((p.x / HALF_WIDTH * 1.1 + 1.1) / 2.2 * cols as f64) as usize;
        let row = ((1.1 - p.y / HALF_HEIGHT * 1.1) / 2.2 * rows as f64) as usize;
        (col.min(cols - 1), row.min(rows - 1))
    };
    let mut grid = vec![vec![' '; cols]; rows];
    for (i, s) in g.sites.iter().enumerate() {
        for &j in s.lanes.iter().filter(|&&j| j > i) {
            let to = g.sites[j].pos;
            let steps = (s.pos.distance(to) * 2.0) as usize;
            for k in 1..steps {
                let (c, r) = cell(s.pos + (to - s.pos) * (k as f64 / steps as f64));
                grid[r][c] = '·';
            }
        }
    }
    for (i, s) in g.sites.iter().enumerate() {
        let (c, r) = cell(s.pos);
        let letter = s.culture.adjective().chars().next().unwrap();
        grid[r][c] = if g.is_seat(i) { letter } else { letter.to_ascii_lowercase() };
    }
    println!("A galaxy of {} systems  (universe {seed})\n", g.sites.len());
    for row in grid {
        println!("  {}", row.into_iter().collect::<String>().trim_end());
    }
    println!("\n  Q/q Qaari  C/c Cant  H/h High Houses  D/d Drift  (capitals: seats)");
    for c in Culture::ALL {
        let held: Vec<usize> = (0..g.sites.len()).filter(|&i| g.sites[i].culture == c).collect();
        let seat = &g.sites[g.seat(c)].name;
        println!("\n{}: {} systems, seat {seat}", c.name().to_uppercase(), held.len());
        for i in held {
            let s = &g.sites[i];
            let start = if i == g.home { "  (the universe began here)" } else { "" };
            let border = s.neighbour.map_or(String::new(), |n| format!(", borders {}", n.name()));
            let lanes = match s.lanes.len() {
                1 => "1 lane".to_string(),
                n => format!("{n} lanes"),
            };
            println!(
                "  {:>3}  {:<16}{:<22}{:<16}{lanes}{border}{start}",
                i + 1,
                s.name,
                s.kind.name(),
                s.star.name
            );
        }
    }
    let count = |k: SystemKind| g.sites.iter().filter(|s| s.kind == k).count();
    let kinds: Vec<String> =
        SystemKind::ALL.into_iter().map(|k| format!("{} {}", count(k), k.name())).collect();
    println!("\n{}", kinds.join(", "));
}

/// Prints a star system in universe `seed`: the `which`th as `galaxy`
/// numbers them, or the one the universe started in.
pub fn print_system(seed: u64, which: Option<u64>) {
    let g = galaxy::generate(seed);
    let site = match which {
        Some(n) if (1..=g.sites.len() as u64).contains(&n) => n as usize - 1,
        Some(n) => {
            println!("There's no system {n}: they're numbered 1 to {}.", g.sites.len());
            return;
        }
        None => g.home,
    };
    let s = g.system(site);
    let kind = match s.kind {
        SystemKind::Seat => format!("the seat of {}", s.culture.name()),
        k => format!("{} held by {}", k.name(), s.culture.name()),
    };
    println!("The {} system, a {}: {kind}  (universe {seed})", s.name, s.star.name);
    println!("\n  {:<26}{:>7}{:>6}{:>9}  what", "planet", "AU", "e", "year");
    for (i, p) in s.planets.iter().enumerate() {
        let people = p.people.map_or(String::new(), |c| format!(", {}", c.adjective()));
        let home = if i == s.home { "  (home)" } else { "" };
        println!(
            "  {:<26}{:>7.2}{:>6.2}{:>8.0}d  {}{people}{home}",
            p.name, p.orbit.a, p.orbit.e, p.orbit.period, p.kind.name
        );
        for m in &p.moons {
            let people = m.people.map_or(String::new(), |c| format!(", {}", c.adjective()));
            let km = m.orbit.a * 149.6e6;
            println!(
                "    moon {:<21}{:>6.0}k km{:>7.1}d  {}{people}",
                m.name,
                km / 1000.0,
                m.orbit.period,
                m.kind.name
            );
        }
    }
    println!("\n  {} lies from {:.2} to {:.2} AU", s.belt.name, s.belt.inner, s.belt.outer);
    for st in &s.stations {
        let point = if st.leading { "L4" } else { "L5" };
        println!("  {} sits at {}'s {point} point", st.name, s.planets[st.planet].name);
    }

    let home = s.home_place();
    let from = s.position(home, 0.0);
    println!(
        "\n  places (⌂ capital, ¤ trade only, · neither), and the trip from {} on day 0:",
        s.places[home].name
    );
    // The wrecks calling on day 0, when a new game starts.
    let calling = s.wrecks_on(0.0);
    for (i, place) in s.places.iter().enumerate() {
        let indent = if matches!(place.kind, PlaceKind::Moon(..) | PlaceKind::Station(_)) {
            "    "
        } else {
            "  "
        };
        let trip = if i == home {
            "you are here".to_string()
        } else {
            format!("{:.1} days", orbit::plan_trip(from, 0.0, |d| s.position(i, d)))
        };
        let wrecks: Vec<String> = calling
            .iter()
            .filter(|w| w.place == i)
            .map(|w| format!("wreck: {}, {} (until day {:.0})", w.name, w.description, w.leaves))
            .collect();
        let mark = match s.landing(i) {
            Landing::Capital(_) => "⌂",
            Landing::Market(_) => "¤",
            _ => "·",
        };
        let name = format!("{indent}{}", place.name);
        println!("{mark} {name:<30}{trip:<14}{}", wrecks.join("; "));
    }
}

/// Prints the `which`th capital in the system you start in, in universe
/// `seed`: the homeworld's first, then the others from the star outwards.
/// With `inside`, prints the inside of one building of each kind too.
pub fn print_town(seed: u64, which: u64, inside: bool) {
    let s = crate::space::home_system(seed);
    let home = s.home_place();
    let mut capitals: Vec<(usize, Culture)> = (0..s.places.len())
        .filter_map(|i| match s.landing(i) {
            Landing::Capital(c) => Some((i, c)),
            _ => None,
        })
        .collect();
    capitals.sort_by_key(|&(i, _)| i != home);
    let Some(&(place, culture)) = capitals.get(which.saturating_sub(1) as usize) else {
        println!("There are only {} capitals in this system.", capitals.len());
        return;
    };
    let people = survey::survey(&s, place, 0.0).population;
    let land = town::Land::of(&s, place, 0.0).expect("a capital is on a planet or moon");
    let t = town::generate(town::seed_for(s.seed, place), culture, town::size_for(people), land);
    let theme = scenes::town::theme(&t);
    println!(
        "{}, the capital of {}: a city of {} on {:?} ground, {} by {}  \
         (universe {seed}, capital {which} of {})\n",
        t.name,
        s.places[place].name,
        culture.name(),
        t.land.terrain,
        t.width(),
        t.height(),
        capitals.len()
    );
    let folk: HashMap<Pos, ()> = t.site.people.iter().map(|p| (p.pos, ())).collect();
    for y in 0..t.height() {
        let row: String = (0..t.width())
            .map(|x| {
                let p = Pos::new(x, y);
                if folk.contains_key(&p) {
                    '&'
                } else {
                    scenes::town::street_look(&t, p, &theme, 0).0
                }
            })
            .collect();
        println!("{}", row.trim_end());
    }
    println!("\nquarters:");
    for q in &t.quarters {
        println!("  {:<28}{:?}", q.name, q.kind);
    }
    println!("\nshops:");
    let wide = t.shops.iter().map(|s| s.name.chars().count()).max().unwrap_or(0) + 2;
    for shop in &t.shops {
        let b = &t.buildings[shop.building];
        let quarter = t.quarter_at(b.door).map_or("", |q| q.name.as_str());
        println!(
            "  {:<wide$}{:<10}kept by {}, in {quarter}",
            shop.name,
            shop.kind.sign(),
            shop.keeper
        );
    }
    let mut kinds: Vec<(String, usize)> = Vec::new();
    for b in &t.buildings {
        let kind = format!("{:?}", b.kind);
        match kinds.iter_mut().find(|(k, _)| *k == kind) {
            Some((_, n)) => *n += 1,
            None => kinds.push((kind, 1)),
        }
    }
    let kinds: Vec<String> = kinds.iter().map(|(k, n)| format!("{n} {k}")).collect();
    println!(
        "\n{} buildings: {}\n{} people in the streets",
        t.buildings.len(),
        kinds.join(", "),
        t.site.people.len()
    );
    if !inside {
        return;
    }
    let mut shown: Vec<String> = Vec::new();
    for (b, building) in t.buildings.iter().enumerate() {
        let kind = format!("{:?}", building.kind);
        if building.barred || shown.contains(&kind) {
            continue;
        }
        shown.push(kind);
        let inside = t.enter(b);
        println!(
            "\n{}  ({} rooms, {} people)",
            building.name,
            inside.room_count(),
            inside.site.people.len()
        );
        for y in 0..inside.site.height {
            let row: String = (0..inside.site.width)
                .map(|x| {
                    let p = Pos::new(x, y);
                    if p == inside.start {
                        '@'
                    } else if inside.site.person_at(p).is_some() {
                        '&'
                    } else {
                        scenes::town::inside_look(&t, &inside, p, &theme, 0).0
                    }
                })
                .collect();
            println!("  {}", row.trim_end());
        }
    }
}

fn number(value: Option<&str>, flag: &str) -> Result<u64, String> {
    let value = value.ok_or(format!("{flag} needs a value"))?;
    value.parse().map_err(|_| format!("{flag}: {value:?} isn't a whole number"))
}

pub fn print_names(opts: &NamesOpts) {
    println!("universe {}  (pass --seed {} to get these again)", opts.seed, opts.seed);
    for &culture in &opts.cultures {
        // Each culture draws from its own seed, so `--culture` alone prints
        // the same names as that culture's section of the full list.
        let mut rng = seed::rng(seed::derive(opts.seed, culture.name(), 0));
        let people: Vec<_> = (0..opts.count).map(|_| culture.person(&mut rng)).collect();
        let places: Vec<_> = (0..opts.count).map(|_| culture.place(&mut rng)).collect();
        println!("\n{}: {}", culture.name().to_uppercase(), culture.blurb());
        println!("  {:<36}places", "people");
        for (person, place) in people.iter().zip(&places) {
            println!("  {person:<36}{place}");
        }
    }
    if opts.cultures.len() == Culture::ALL.len() {
        let mut rng = seed::rng(seed::derive(opts.seed, "artifacts", 0));
        println!("\nARTIFACTS: as found -> once identified");
        for _ in 0..opts.count {
            let a = names::artifact(&mut rng);
            println!("  {:<40}{}", a.unidentified, a.true_name);
        }
    }
}

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

    fn args(s: &str) -> Vec<String> {
        s.split_whitespace().map(String::from).collect()
    }

    #[test]
    fn parses_play_and_names() {
        assert!(matches!(parse(&args("")), Ok(Command::Play { seed: None })));
        assert!(matches!(parse(&args("--seed 42")), Ok(Command::Play { seed: Some(42) })));
        let Ok(Command::Names(opts)) = parse(&args("names --culture drift -n 3 --seed 9")) else {
            panic!("names didn't parse");
        };
        assert_eq!((opts.cultures, opts.count, opts.seed), (vec![Culture::Drift], 3, 9));
    }

    #[test]
    fn rejects_names_flags_when_playing() {
        assert!(parse(&args("-n 3")).is_err());
        assert!(parse(&args("--culture cant")).is_err());
        assert!(parse(&args("names --culture nobody")).is_err());
        assert!(parse(&args("--seed lots")).is_err());
    }
}