#include "sailselection.h"
#include "data_xp44.h"
#include <cmath>
using namespace std;

const vector<sail_zone> SSC::zones { sail_data::zones };

string SSC::compute_range_tag(const sail_zone& z, double tws, double twa) const {
    const trapezoid& t {z.primary};

    // interpolation ratio of tws within the zone's tws range at given twa
    const double twa_ratio {(twa - t.twa_min_thin) / (t.twa_max_thin - t.twa_min_thin)};
    const double tws_min_at_twa {t.tws_min_thin + (t.tws_min_deep - t.tws_min_thin) * twa_ratio};
    const double tws_max_at_twa {t.tws_max_thin + (t.tws_max_deep - t.tws_max_thin) * twa_ratio};
    const double tws_ratio {(tws - tws_min_at_twa) / (tws_max_at_twa - tws_min_at_twa)};

    // interpolation ratio of twa within the zone's twa range at given tws
    const double tws_ratio2 {(tws - t.tws_min_thin) / (t.tws_max_thin - t.tws_min_thin)};
    const double twa_min_at_tws {t.twa_min_thin + (t.twa_min_deep - t.twa_min_thin) * tws_ratio2};
    const double twa_max_at_tws {t.twa_max_thin + (t.twa_max_deep - t.twa_max_thin) * tws_ratio2};
    const double twa_ratio2 {(twa - twa_min_at_tws) / (twa_max_at_tws - twa_min_at_tws)};

    // combined position within zone
    const double position {(tws_ratio + twa_ratio2) / 2.0};

    return position > 0.5 ? "uprange" : "downrange";
}

string SSC::reef(double tws, double twa) const {
    bool r1 {false};
    bool r2 {false};
    for (const sail_zone& z : zones) {
        if (!z.is_reef) continue;
        const trapezoid& t {z.primary};
        const double twa_ratio {(twa - t.twa_min_thin) / (t.twa_max_thin - t.twa_min_thin)};
        const double tws_min_at_twa {t.tws_min_thin + (t.tws_min_deep - t.tws_min_thin) * twa_ratio};
        const double tws_max_at_twa {t.tws_max_thin + (t.tws_max_deep - t.tws_max_thin) * twa_ratio};
        const double tws_ratio {(tws - tws_min_at_twa) / (tws_max_at_twa - tws_min_at_twa)};
        const double twa_min_at_tws {t.twa_min_thin + (t.twa_min_deep - t.twa_min_thin) * tws_ratio};
        const double twa_max_at_tws {t.twa_max_thin + (t.twa_max_deep - t.twa_max_thin) * tws_ratio};
        if (tws >= tws_min_at_twa && tws <= tws_max_at_twa &&
            twa >= twa_min_at_tws && twa <= twa_max_at_tws) {
            if (z.name == "R1") r1 = true;
            if (z.name == "R2") r2 = true;
        }
    }
    if (r2) return "Reef 1 and Reef 2";
    if (r1) return "Reef 1";
    return "";
}

vector<sail_rec> SSC::lookup(double tws, double twa) const {
    vector<sail_rec> results;
    for (const sail_zone& z : zones) {
        if (z.is_reef) continue;
        const trapezoid& p {z.primary};
        const trapezoid& o {z.overlap};

        // check if point is inside a trapezoid
        auto in_trap = [](const trapezoid& t, double tws, double twa) -> bool {
            const double twa_ratio {(twa - t.twa_min_thin) / (t.twa_max_thin - t.twa_min_thin)};
            if (twa_ratio < 0.0 || twa_ratio > 1.0) return false;
            const double tws_min_at_twa {t.tws_min_thin + (t.tws_min_deep - t.tws_min_thin) * twa_ratio};
            const double tws_max_at_twa {t.tws_max_thin + (t.tws_max_deep - t.tws_max_thin) * twa_ratio};
            if (tws < tws_min_at_twa || tws > tws_max_at_twa) return false;
            const double tws_ratio {(tws - t.tws_min_thin) / (t.tws_max_thin - t.tws_min_thin)};
            const double twa_min_at_tws {t.twa_min_thin + (t.twa_min_deep - t.twa_min_thin) * tws_ratio};
            const double twa_max_at_tws {t.twa_max_thin + (t.twa_max_deep - t.twa_max_thin) * tws_ratio};
            return twa >= twa_min_at_tws && twa <= twa_max_at_tws;
        };

        const bool in_primary {in_trap(p, tws, twa)};
        const bool in_overlap {in_trap(o, tws, twa)};

        if (in_primary) {
            results.push_back({z.name, z.display_name, "", false});
        } else if (in_overlap) {
            results.push_back({z.name, z.display_name,
                compute_range_tag(z, tws, twa), false});
        }
    }

    // reef check stacks on top of sail results
    const string reef_str {reef(tws, twa)};
    if (!reef_str.empty()) {
        results.push_back({"REEF", reef_str, "", true});
    }

    return results;
}

ostream& operator<<(ostream& os, const sail_rec& r) {
    os << "<p>";
    os << r.display_name;
    if (!r.range.empty()) {
        os << " &mdash; " << r.range;
    }
    if (r.is_reef) {
        os << " <strong>recommended</strong>";
    }
    os << "</p>\n";
    return os;
}