#include "../../include/ground.h"

static inline void doLabels(GroundProgram* program, GroundState* state) {

    for (GroundSize i = 0; i < program->len; i++) {
        GroundInstruction* instruction = &program->at[i];
        if (instruction->type == GroundInstruction_CREATELABEL) {
            if (instruction->args.len > 0) {
                GroundArg* arg = &instruction->args.at[0];
                GroundLabel* label = NULL;
                HASH_FIND_STR(state->labels, arg->as.ref->string, label);

                if (label == NULL) {
                    label = malloc(sizeof(GroundLabel));
                    if (label == NULL) {
                        Ground.Log.Error("malloc failed in Ground.Internal.run()");
                        Ground.Flags.error = true;
                        return;
                    }
                    strncpy(label->name, arg->as.ref->string, 2047);
                    label->name[2047] = '\0';
                    label->lineNum = i;
                    HASH_ADD_STR(state->labels, name, label);
                } 
            }
        }
    }

    for (GroundSize i = 0; i < program->len; i++) {
        GroundInstruction* instruction = &program->at[i];
        if (instruction->type == GroundInstruction_JUMP) {
            GroundArg* arg = &instruction->args.at[0];
            GroundSize* line = Ground.State.findLabel(state, arg->as.ref->string);
            if (line == NULL) {
                char buf[2048];
                snprintf(buf, 2047, "couldn't find label '%s' (instruction JUMP at %zu) in Ground.Internal.Run()", arg->as.ref->string, i);
                Ground.Log.Error(buf);
                Ground.Flags.error = true;
                return;
            }

            arg->_offset = *line;

        } else if (instruction->type == GroundInstruction_IF) {
            GroundArg* arg = &instruction->args.at[1];
            GroundSize* line = Ground.State.findLabel(state, arg->as.ref->string);
            if (line == NULL) {
                char buf[2048];
                snprintf(buf, 2047, "couldn't find label '%s' (instruction IF at %zu) in Ground.Internal.Run()", arg->as.ref->string, i);
                Ground.Log.Error(buf);
                Ground.Flags.error = true;
                return;
            }

            arg->_offset = *line;
            
        } else if (instruction->type == GroundInstruction_CATCH) {
            GroundArg* arg = &instruction->args.at[1];
            GroundSize* line = Ground.State.findLabel(state, arg->as.ref->string);
            if (line == NULL) {
                char buf[2048];
                snprintf(buf, 2047, "couldn't find label '%s' (instruction CATCH at %zu) in Ground.Internal.Run()", arg->as.ref->string, i);
                Ground.Log.Error(buf);
                Ground.Flags.error = true;
                return;
            }

            arg->_offset = *line;

        }
    }

}

/*
 * Assigns an offset to each variable referenced.
 */
static inline GroundSize doOffsets(GroundProgram* gp, GroundState* state, GroundBytecodeProgram* gbp) {
    GroundSize size = 0;

    // Add size of state and assign offsets to pre-existing variables
    GroundVariable *s, *tmp;
    HASH_ITER(hh, state->variables, s, tmp) {
        s->_offset = size++;
    }

    for (GroundSize i = 0; i < gp->len; i++) {
        for (GroundSize j = 0; j < gp->at[i].args.len; j++) {
            GroundArg* arg = &gp->at[i].args.at[j];

            if (
                arg->type == GroundArg_Label ||
                arg->type == GroundArg_LineRef
               ) continue;

            if (arg->type == GroundArg_Value) {
                GroundVariable* item = malloc(sizeof(GroundVariable));
                if (item == NULL) {
                    Ground.Log.Error("malloc failed in Ground.Internal.run()");
                    Ground.Flags.error = true;
                    return 0;
                }
                item->value = Ground.Copy.Value(&arg->as.value);
                if (Ground.Flags.error) return 0;
                item->_offset = size++;
                snprintf(item->name, sizeof(item->name) - 1, "_._.ground_internal_constant_%zu", item->_offset);
                HASH_ADD_STR(state->variables, name, item);
                arg->_offset = item->_offset;
                continue;
            }

            GroundVariable* item = NULL;
            HASH_FIND_STR(state->variables, arg->as.ref->string, item);

            if (item == NULL) {
                item = malloc(sizeof(GroundVariable));
                if (item == NULL) {
                    Ground.Log.Error("malloc failed in Ground.Internal.run()");
                    Ground.Flags.error = true;
                    return 0;
                }
                item->value = Ground.New.Value.Int(0);
                strncpy(item->name, arg->as.ref->string, 2047);
                item->_offset = size++;
                HASH_ADD_STR(state->variables, name, item);
            }

            arg->_offset = item->_offset;
        }

        // Convert to GroundBytecodeInstruction
        GroundBytecodeInstruction inst = {
            .type = gp->at[i].type,
            .args.at = malloc(sizeof(GroundSize) * gp->at[i].args.len),
            .args.len = gp->at[i].args.len,
            .args.capacity = gp->at[i].args.len
        };

        if (inst.args.at == NULL) {
            Ground.Log.Error("malloc failed in Ground.Internal.run()");
            Ground.Flags.error = true;
            return 0;
        }

        for (GroundSize j = 0; j < gp->at[i].args.len; j++) {
            inst.args.at[j] = gp->at[i].args.at[j]._offset;
        }

        gbp->at[i] = inst;
        gbp->len++;

    }
    return size;
}


GroundBytecode _GroundNewBytecode(GroundProgram* program, GroundState* state) {

    GroundBytecode bytecode = {
        .program = {
            .at = malloc(sizeof(GroundBytecodeInstruction) * program->len),
            .capacity = program->len,
            .len = 0,
        },
        .heap = {
            .heap = NULL,
            .capacity = 0,
            .len = 0
        }
    };

    if (bytecode.program.at == NULL) {
        Ground.Log.Error("malloc failed in Ground.New.Bytecode");
        Ground.Flags.error = true;
        return bytecode;
    }

    // Add core types to state 
    for (unsigned int i = 0; i < (unsigned int)GroundType_Object; i++) {
        GroundVariable* var = malloc(sizeof(GroundVariable));
        if (var == NULL) {
            Ground.Log.Error("malloc failed in Ground.New.Bytecode");
            Ground.Flags.error = true;
            return bytecode;
        }
        var->value = (GroundValue) {
            .type = {GroundType_CoreType},
            .as.CoreType = (enum GroundTypeType) i
        };

        switch ((enum GroundTypeType) i) {
            case GroundType_Int: {
                sprintf(var->name, "int");
                break;
            }
            case GroundType_Double: {
                sprintf(var->name, "double");
                break;
            }
            case GroundType_Char: {
                sprintf(var->name, "char");
                break;
            }
            case GroundType_Bool: {
                sprintf(var->name, "bool");
                break;
            }
            case GroundType_String: {
                sprintf(var->name, "string");
                break;
            }
            case GroundType_List: {
                sprintf(var->name, "list");
                break;
            }
            case GroundType_Function: {
                sprintf(var->name, "function");
                break;
            }
            case GroundType_Struct: {
                sprintf(var->name, "struct");
                break;
            }
            default: break; // unreachable (in theory)
        }

        HASH_ADD_STR(state->variables, name, var);

    }

    state->_size += (unsigned int)GroundType_Object + 1;

    // Precompute some really cool stuff
    doLabels(program, state);
    if (Ground.Flags.error) return bytecode;

    GroundSize size = doOffsets(program, state, &bytecode.program);
    if (Ground.Flags.error) return bytecode;

    // Allocate heap
    bytecode.heap.heap = malloc(sizeof(GroundBytecodeValue) * size);
    if (bytecode.heap.heap == NULL) {
        Ground.Log.Error("malloc failed in Ground.New.Bytecode");
        Ground.Flags.error = true;
        return bytecode;
    }
    bytecode.heap.capacity = size;
    bytecode.heap.len = size;

    GroundVariable *s, *tmp;

    // Copy constants into heap at their assigned offsets
    HASH_ITER(hh, state->variables, s, tmp) {
        bytecode.heap.heap[s->_offset] = Ground.New.BytecodeValue(Ground.Copy.Value(&s->value));
        if (Ground.Flags.error) return bytecode;
    }


    return bytecode;
    
}