/*  Starshatter OpenSource Distribution
    Copyright (c) 1997-2004, Destroyer Studios LLC.
    All Rights Reserved.

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    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
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      may be used to endorse or promote products derived from this software
      without specific prior written permission.

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    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

    SUBSYSTEM:    Stars.exe
    FILE:         CampaignPlanStrategic.cpp
    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    CampaignPlanStrategic prioritizes targets and defensible
    allied forces as the first step in force tasking.
*/

#include "MemDebug.h"
#include "CampaignPlanStrategic.h"
#include "Campaign.h"
#include "Combatant.h"
#include "CombatGroup.h"
#include "CombatUnit.h"
#include "CombatZone.h"
#include "Random.h"

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ExecFrame()
{
    if (campaign && campaign->IsActive()) {
        if (Campaign::Stardate() - exec_time < 300)
        return;

        ListIter<CombatZone> zone = campaign->GetZones();
        while (++zone)
        zone->Clear();

        ListIter<Combatant>  iter = campaign->GetCombatants();
        while (++iter) {
            Combatant*     c     = iter.value();
            CombatGroup*   force = c->GetForce();

            force->CalcValue();

            PlaceGroup(force);
            ScoreCombatant(c);
            ScoreNeeds(c);

            force->ClearUnlockedZones();
            AssignZones(c);
            ResolveZoneMovement(force);
        }

        exec_time = Campaign::Stardate();
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::PlaceGroup(CombatGroup* g)
{
    if (!g)
    return;

    Text        rgn  = g->GetRegion();
    CombatZone* zone = campaign->GetZone(rgn);

    // if we couldn't find anything suitable,
    // just pick a zone at random:
    if (!zone && g->IsMovable()) {
        int nzones = campaign->GetZones().size();
        int n      = RandomIndex() % nzones;
        zone       = campaign->GetZones().at(n);

        Text assigned_rgn;
        if (!campaign->GetZone(rgn)) {
            assigned_rgn = *zone->GetRegions().at(0);
            g->AssignRegion(assigned_rgn);
        }
    }

    if (zone && !zone->HasGroup(g))
    zone->AddGroup(g);

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter)
    PlaceGroup(iter.value());
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreCombatant(Combatant* c)
{
    // prep lists:
    c->GetDefendList().clear();
    c->GetTargetList().clear();

    ScoreDefensible(c);

    ListIter<Combatant> iter = campaign->GetCombatants();
    while (++iter) {
        if (iter->GetIFF() > 0 && iter->GetIFF() != c->GetIFF())
        ScoreTargets(c, iter.value());
    }

    // sort lists:
    c->GetDefendList().sort();
    c->GetTargetList().sort();
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreDefensible(Combatant* c)
{
    if (c->GetForce())
    ScoreDefend(c, c->GetForce());
}

void
CampaignPlanStrategic::ScoreDefend(Combatant* c, CombatGroup* g)
{
    if (!g || g->IsReserve())
    return;

    if (g->IsDefensible()) {
        g->SetPlanValue(g->Value());
        c->GetDefendList().append(g);

        CombatZone* zone  = campaign->GetZone(g->GetRegion());
        ZoneForce*  force = 0;

        if (zone)
        force = zone->FindForce(c->GetIFF());

        if (force)
        force->GetDefendList().append(g);
    }

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter) {
        ScoreDefend(c, iter.value());
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreTargets(Combatant* c, Combatant* t)
{
    if (t->GetForce())
    ScoreTarget(c, t->GetForce());
}

void
CampaignPlanStrategic::ScoreTarget(Combatant* c, CombatGroup* g)
{
    if (!g || g->IntelLevel() <= Intel::SECRET)
    return;

    if (g->IsTargetable()) {
        g->SetPlanValue(g->Value() * c->GetTargetStratFactor(g->Type()));
        c->GetTargetList().append(g);

        CombatZone* zone  = campaign->GetZone(g->GetRegion());
        ZoneForce*  force = 0;

        if (zone)
        force = zone->FindForce(c->GetIFF());

        if (force)
        force->GetTargetList().append(g);
    }

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter) {
        ScoreTarget(c, iter.value());
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreNeeds(Combatant* c)
{
    ListIter<CombatZone> zone = campaign->GetZones();
    while (++zone) {
        ZoneForce* force = zone->FindForce(c->GetIFF());

        // clear needs:
        force->SetNeed(CombatGroup::CARRIER_GROUP,      0);
        force->SetNeed(CombatGroup::BATTLE_GROUP,       0);
        force->SetNeed(CombatGroup::DESTROYER_SQUADRON, 0);
        force->SetNeed(CombatGroup::ATTACK_SQUADRON,    0);
        force->SetNeed(CombatGroup::FIGHTER_SQUADRON,   0);
        force->SetNeed(CombatGroup::INTERCEPT_SQUADRON,   0);

        // what defensive assets are needed in this zone?
        ListIter<CombatGroup> def = force->GetDefendList();
        while (++def) {
            int defender_type = *CombatGroup::PreferredDefender(def->Type());
            force->AddNeed(defender_type, def->Value());
        }

        // what offensive assets are needed in this zone?
        ListIter<CombatGroup> tgt = force->GetTargetList();
        while (++tgt) {
            int attacker_type = *CombatGroup::PreferredAttacker(tgt->Type());
            force->AddNeed(attacker_type, tgt->Value());
        }
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::BuildGroupList(CombatGroup* g, List<CombatGroup>& groups)
{
    if (!g || g->IsReserve())
    return;

    if (g->IsAssignable())
    groups.append(g);

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter)
    BuildGroupList(iter.value(), groups);
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::AssignZones(Combatant* c)
{
    // find the list of assignable groups, in priority order:
    List<CombatGroup> groups;
    BuildGroupList(c->GetForce(), groups);
    groups.sort();

    // for each group, assign a zone:
    ListIter<CombatGroup> g_iter = groups;

    // first pass: fighter and attack squadrons assigned to star bases
    while (++g_iter) {
        CombatGroup* g     = g_iter.value();
        int          gtype = g->Type();

        if (gtype == CombatGroup::ATTACK_SQUADRON    ||
                gtype == CombatGroup::FIGHTER_SQUADRON   ||
                gtype == CombatGroup::INTERCEPT_SQUADRON) {
            CombatGroup* parent = g->GetParent();

            if (parent && parent->Type() == CombatGroup::WING)
            parent = parent->GetParent();

            if (!parent || parent->Type() == CombatGroup::CARRIER_GROUP)
            continue;

            // these groups are attached to fixed resources,
            // so they must be assigned to the parent's zone:
            CombatZone* parent_zone = campaign->GetZone(parent->GetRegion());

            if (parent_zone) {
                ZoneForce*  parent_force = parent_zone->FindForce(g->GetIFF());

                if (parent_force) {
                    g->SetAssignedZone(parent_zone);
                    parent_force->AddNeed(g->Type(), -(g->Value()));
                }
            }
        }
    }

    // second pass: carrier groups
    g_iter.reset();
    while (++g_iter) {
        CombatGroup* g     = g_iter.value();
        int          gtype = g->Type();

        if (gtype == CombatGroup::CARRIER_GROUP) {
            int         current_zone_need = 0;
            int         highest_zone_need = 0;
            CombatZone* highest_zone      = 0;
            ZoneForce*  highest_force     = 0;
            CombatZone* current_zone      = 0;
            ZoneForce*  current_force     = 0;

            List<CombatZone> possible_zones;

            if (g->IsZoneLocked()) {
                current_zone  = g->GetAssignedZone();
                current_force = current_zone->FindForce(g->GetIFF());
            }

            else {
                ListIter<CombatZone> z_iter = campaign->GetZones();
                while (++z_iter) {
                    CombatZone* zone  = z_iter.value();
                    ZoneForce*  force = zone->FindForce(g->GetIFF());
                    int         need  = force->GetNeed(CombatGroup::CARRIER_GROUP)     +
                    force->GetNeed(CombatGroup::ATTACK_SQUADRON)   +
                    force->GetNeed(CombatGroup::FIGHTER_SQUADRON)  +
                    force->GetNeed(CombatGroup::INTERCEPT_SQUADRON);

                    if (g->IsSystemLocked() && zone->System() != g->GetAssignedSystem())
                    continue;

                    possible_zones.append(zone);

                    if (zone->HasRegion(g->GetRegion())) {
                        current_zone_need = need;
                        current_zone      = zone;
                        current_force     = force;
                    }

                    if (need > highest_zone_need) {
                        highest_zone_need = need;
                        highest_zone      = zone;
                        highest_force     = force;
                    }
                }
            }

            CombatZone* assigned_zone  = current_zone;
            ZoneForce*  assigned_force = current_force;

            if (highest_zone_need > current_zone_need) {
                assigned_zone  = highest_zone;
                assigned_force = highest_force;
            }

            // if we couldn't find anything suitable,
            // just pick a zone at random:
            if (!assigned_zone) {
                if (possible_zones.isEmpty())
                possible_zones.append(campaign->GetZones());

                int nzones = possible_zones.size();
                int n      = RandomIndex() % nzones;

                assigned_zone  = possible_zones.at(n);
                assigned_force = assigned_zone->FindForce(g->GetIFF());
            }

            if (assigned_force && assigned_zone) {
                Text assigned_rgn;
                if (!campaign->GetZone(g->GetRegion())) {
                    assigned_rgn = *assigned_zone->GetRegions().at(0);
                    g->AssignRegion(assigned_rgn);
                }

                g->SetAssignedZone(assigned_zone);
                assigned_force->AddNeed(g->Type(), -(g->Value()));

                // also assign the carrier's wing and squadrons to the same zone:
                ListIter<CombatGroup> squadron = g->GetComponents();
                while (++squadron) {
                    squadron->SetAssignedZone(assigned_zone);
                    assigned_force->AddNeed(squadron->Type(), -(squadron->Value()));

                    if (squadron->Type() == CombatGroup::WING) {
                        ListIter<CombatGroup> s = squadron->GetComponents();
                        while (++s) {
                            s->SetAssignedZone(assigned_zone);
                            assigned_force->AddNeed(s->Type(), -(s->Value()));
                        }
                    }
                }
            }
        }
    }

    // third pass: everything else
    g_iter.reset();
    while (++g_iter) {
        CombatGroup* g     = g_iter.value();
        int          gtype = g->Type();

        if (gtype == CombatGroup::BATTLE_GROUP || gtype == CombatGroup::DESTROYER_SQUADRON) {
            int         current_zone_need = 0;
            int         highest_zone_need = 0;
            CombatZone* highest_zone      = 0;
            ZoneForce*  highest_force     = 0;
            CombatZone* current_zone      = 0;
            ZoneForce*  current_force     = 0;

            List<CombatZone> possible_zones;

            if (g->IsZoneLocked()) {
                current_zone  = g->GetAssignedZone();
                current_force = current_zone->FindForce(g->GetIFF());
            }

            else {
                ListIter<CombatZone> z_iter = campaign->GetZones();
                while (++z_iter) {
                    CombatZone* zone  = z_iter.value();
                    ZoneForce*  force = zone->FindForce(g->GetIFF());
                    int         need  = force->GetNeed(g->Type());

                    if (g->IsSystemLocked() && zone->System() != g->GetAssignedSystem())
                    continue;

                    possible_zones.append(zone);

                    // battle groups can do double-duty:
                    if (gtype == CombatGroup::BATTLE_GROUP)
                    need += force->GetNeed(CombatGroup::DESTROYER_SQUADRON);

                    if (zone->HasRegion(g->GetRegion())) {
                        current_zone_need = need;
                        current_zone      = zone;
                        current_force     = force;
                    }

                    if (need > highest_zone_need) {
                        highest_zone_need = need;
                        highest_zone      = zone;
                        highest_force     = force;
                    }
                }
            }

            if (highest_zone_need > current_zone_need) {
                g->SetAssignedZone(highest_zone);

                if (highest_force)
                highest_force->AddNeed(g->Type(), -(g->Value()));
            }
            else {
                if (!current_zone) {
                    if (possible_zones.isEmpty())
                    possible_zones.append(campaign->GetZones());

                    int nzones = possible_zones.size();
                    int n      = RandomIndex() % nzones;

                    current_zone  = possible_zones.at(n);
                    current_force = current_zone->FindForce(g->GetIFF());
                }

                g->SetAssignedZone(current_zone);

                if (current_force)
                current_force->AddNeed(g->Type(), -(g->Value()));

                Text assigned_rgn;
                if (!campaign->GetZone(g->GetRegion())) {
                    assigned_rgn = *current_zone->GetRegions().at(0);
                    g->AssignRegion(assigned_rgn);
                }
            }
        }
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ResolveZoneMovement(CombatGroup* g)
{
    CombatZone* zone = g->GetAssignedZone();
    bool        move = false;

    if (zone && !zone->HasRegion(g->GetRegion())) {
        move = true;
        CombatZone* old_zone = g->GetCurrentZone();
        if (old_zone)
        old_zone->RemoveGroup(g);
        zone->AddGroup(g);
    }

    ListIter<CombatGroup> comp = g->GetComponents();
    while (++comp)
    ResolveZoneMovement(comp.value());

    // assign region last, to allow components to
    // resolve their zones:
    if (zone && move)
    g->AssignRegion(*zone->GetRegions().at(0));
}