// Headless test for the ecoregion atlas. No display needed.

#include "Planet.hpp"
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <set>
#include <sstream>

static int failures = 0;
static void check(bool cond, const char* what) {
    std::printf("  [%s] %s\n", cond ? "PASS" : "FAIL", what);
    if (!cond) ++failures;
}

static void settle(Planet& p, int maxSteps = 800) {
    int run = 0;
    for (int s = 0; s < maxSteps; ++s) {
        double mc = p.step();
        if (mc < 2.0) { if (++run >= 3) break; } else run = 0;
    }
    p.computeClimate();
    p.classifyBiomes();
    p.computeBiotaDensity();
}

static bool sameBiota(const std::vector<CellBiota>& a, const std::vector<CellBiota>& b) {
    if (a.size() != b.size()) return false;
    auto eq = [](const std::vector<Organism>& x, const std::vector<Organism>& y) {
        if (x.size() != y.size()) return false;
        for (size_t k = 0; k < x.size(); ++k)
            if (x[k].archetype != y[k].archetype || x[k].biome != y[k].biome) return false;
        return true;
    };
    for (size_t i = 0; i < a.size(); ++i)
        if (!eq(a[i].flora, b[i].flora) || !eq(a[i].fauna, b[i].fauna) || !eq(a[i].funga, b[i].funga))
            return false;
    return true;
}

int main() {
    PlanetConfig cfg; cfg.seed = 9191; cfg.subdivisions = 5;
    Planet p; p.generate(cfg); settle(p);
    const int n = (int)p.cells.size();

    std::printf("Ecoregions: extraction\n");
    p.generateEcoregions();
    const auto& E = p.ecoregions();
    const auto& ce = p.cellEcoregion();
    check(!E.empty(), "generateEcoregions produces regions");
    check((int)ce.size() == n, "per-cell ecoregion array sized n");

    bool mapped = true, indexOk = true, anchorsOk = true, namesOk = true, domOk = true;
    std::set<std::string> names;
    for (int i = 0; i < n; ++i) {
        if (p.cells[i].biome != Biome::Ice && ce[i] < 0) mapped = false;
        if (ce[i] >= (int)E.size()) indexOk = false;
    }
    for (const Ecoregion& e : E) {
        if (e.name.empty() || !names.insert(e.name).second) namesOk = false;
        if (e.anchorCell < 0 || e.anchorCell >= n || p.cells[e.anchorCell].biome != e.biome
            || e.biome == Biome::Ice) anchorsOk = false;
        auto validArch = [](int a) { return a == -1 || (a >= 0 && a < (int)biotaArchetypes().size()); };
        if (!validArch(e.dominantFlora) || !validArch(e.dominantFauna) || !validArch(e.dominantFunga)) domOk = false;
        if (!std::isfinite(e.floraProductivity) || !std::isfinite(e.faunaProductivity)
            || !std::isfinite(e.fungaProductivity)) domOk = false;
    }
    check(mapped, "every non-ice cell maps to an ecoregion");
    check(indexOk, "per-cell ecoregion indices are valid");
    check(anchorsOk, "ecoregion anchors match their biome");
    check(namesOk, "ecoregion names are unique and non-empty");
    check(domOk, "dominants/productivity are valid");

    std::printf("Ecoregions: determinism\n");
    Planet q; q.generate(cfg); settle(q); q.generateEcoregions();
    bool same = (q.ecoregions().size() == E.size()) && (q.cellEcoregion() == ce);
    if (same)
        for (size_t i = 0; i < E.size(); ++i) {
            const Ecoregion& a = E[i]; const Ecoregion& b = q.ecoregions()[i];
            if (a.name != b.name || a.biome != b.biome || a.anchorCell != b.anchorCell
                || a.size != b.size || a.dominantFlora != b.dominantFlora
                || a.dominantFauna != b.dominantFauna || a.dominantFunga != b.dominantFunga) {
                same = false; break;
            }
        }
    check(same, "same seed produces identical ecoregions");

    std::printf("Ecoregions: RNG isolation\n");
    {
        Planet a; a.generate(cfg); settle(a); a.drifting = true;
        Planet b; b.generate(cfg); settle(b); b.drifting = true; b.generateEcoregions();
        double dt = a.cflDtMy();
        for (int k = 0; k < 5; ++k) { a.advect(dt); a.step(); a.erode(dt);
                                      b.advect(dt); b.step(); b.erode(dt); }
        bool terrainSame = a.cells.size() == b.cells.size();
        for (size_t i = 0; terrainSame && i < a.cells.size(); ++i)
            if (a.cells[i].elevation != b.cells[i].elevation || a.cells[i].plateId != b.cells[i].plateId)
                terrainSame = false;
        check(terrainSame, "ecoregions do not perturb tectonic evolution");
    }
    {
        Planet a; a.generate(cfg); settle(a); a.generateBiota();
        Planet b; b.generate(cfg); settle(b); b.generateEcoregions(); b.generateBiota();
        check(a.biotaPopulated() && b.biotaPopulated() && sameBiota(a.biota(), b.biota()),
              "ecoregions do not perturb biota generation");
    }

    std::printf("Ecoregions: save v19 round-trip\n");
    {
        std::stringstream ss(std::ios::in | std::ios::out | std::ios::binary);
        p.writeState(ss);
        Planet r;
        bool ok = r.readState(ss);
        check(ok, "readState accepts a v19 stream");
        bool match = (r.ecoregions().size() == E.size()) && (r.cellEcoregion() == ce);
        if (match)
            for (size_t i = 0; i < E.size(); ++i)
                if (r.ecoregions()[i].name != E[i].name || r.ecoregions()[i].biome != E[i].biome
                    || r.ecoregions()[i].anchorCell != E[i].anchorCell) { match = false; break; }
        check(match, "ecoregions round-trip through save");

        ss.clear(); ss.seekg(0);
        Planet old;
        bool okOld = old.readState(ss, true, true, true, true, true, true, true, true, true, false);
        check(okOld && old.ecoregions().empty(), "pre-v19 read leaves ecoregions empty");
    }

    std::printf("\n%s (%d failure%s)\n", failures ? "FAILURES" : "ALL ECOREGION CHECKS PASSED",
                failures, failures == 1 ? "" : "s");
    return failures ? 1 : 0;
}