#include <dirent.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "Compiler.h"
#include "Script.h"
#include "Tokenizer.h"

static int doneTests = 0;
static int allTests = 0;
static char path[PATH_MAX] = {'\0'};
static int pathIndex = 0;

#define TEST_BUFFER_LENGTH (1024 * 2)
static char testBuffer[TEST_BUFFER_LENGTH];
static int testBufferIndex = 0;

static void tsAddBufferIndex(int length) {
    testBufferIndex += length;
    if(testBufferIndex > TEST_BUFFER_LENGTH) {
        testBufferIndex = TEST_BUFFER_LENGTH;
    }
}

static bool tsPrinter(Object* o) {
    if(testBufferIndex >= TEST_BUFFER_LENGTH) {
        return true;
    }
    if(o->type == OT_INT) {
        int leftBytes = TEST_BUFFER_LENGTH - testBufferIndex;
        tsAddBufferIndex(snprintf(testBuffer + testBufferIndex, leftBytes, "%d\n", o->data.intValue));
        return false;
    }
    return true;
}

static void tsAppend(const char* s) {
    for(int i = 0; pathIndex < (PATH_MAX - 1) && s[i] != '\0'; i++) {
        path[pathIndex++] = s[i];
    }
    path[pathIndex] = '\0';
}

static int tsEnter(const char* s) {
    int marker = pathIndex;
    tsAppend("/");
    tsAppend(s);
    return marker;
}

static void tsReset(int marker) {
    path[marker] = '\0';
    pathIndex = marker;
}

static void tsCompareResults(FILE* file) {
    for(int i = 0; i < testBufferIndex; i++) {
        char a = fgetc(file);
        char b = testBuffer[i];
        if(a != b) {
            printf("error in '%s': expected %c, got:\n%s", path, a, testBuffer + i);
            return;
        }
    }
    if(fgetc(file) != EOF) {
        printf("error in '%s': no full read\n", path);
        return;
    }
    doneTests++;
}

static void tsCheckScript(Script* sc) {
    testBufferIndex = 0;
    sRun(sc);

    tsAppend(".out");
    FILE* file = fopen(path, "r");
    if(file == NULL) {
        printf("cannot open result file '%s'\n", path);
        return;
    }
    tsCompareResults(file);
    fclose(file);
}

static void tsCheckFile() {
    allTests++;
    if(tTokenize(path)) {
        puts(tGetError());
        return;
    }
    int codeLength;
    unsigned char* code = cCompile(&codeLength);
    if(code == NULL) {
        puts(cGetError());
        return;
    }
    Script* sc = sInit(code, codeLength);
    tsCheckScript(sc);
    sDelete(sc);
}

static void tsScanDirectory() {
    DIR* dir = opendir(path);
    if(dir == NULL) {
        printf("cannot open '%s': %s\n", path, strerror(errno));
        return;
    }
    while(true) {
        struct dirent* e = readdir(dir);
        if(e == NULL) {
            return;
        } else if(strcmp(e->d_name, ".") == 0 || strcmp(e->d_name, "..") == 0) {
            continue;
        } else if(e->d_type == DT_DIR) {
            int marker = tsEnter(e->d_name);
            tsScanDirectory();
            tsReset(marker);
        } else if(e->d_type == DT_REG && strchr(e->d_name, '.') == NULL) {
            int marker = tsEnter(e->d_name);
            tsCheckFile();
            tsReset(marker);
        }
    }
    if(closedir(dir)) {
        printf("cannot close '%s': %s\n", path, strerror(errno));
    }
}

/*static String readLine(std::ifstream& f) {
    String s;
    while(true) {
        char c = f.get();
        if(!f.good() || c == '\n') {
            break;
        }
        s += c;
    }
    return s;
}

static bool testTokenizer(const String& input, const String& output) {
    tests++;
    std::ifstream oStream;
    oStream.open(output);
    if(!oStream.good()) {
        std::cout << "cannot open file '" << output << "'\n";
        return true;
    }
    TokenStream tokenStream;
    if(Tokenizer::tokenize(tokenStream, input)) {
        return true;
    }
    while(true) {
        String expected = readLine(oStream);
        if(expected.getLength() == 0) {
            break;
        } else if(!tokenStream.hasToken()) {
            std::cout << "error in '" << input << "\n'out of tokens\n";
            return false;
        }
        String buffer = tokenStream.nextTokenString();
        if(strchr(buffer, '\n') != nullptr) {
            expected += '\n';
            expected += readLine(oStream);
        }
        if(strcmp(buffer, expected) != 0) {
            std::cout << "error in '" << input << "\n'" << buffer << "' should be '" << expected << "'\n";
            return false;
        }
    }
    done++;
    return false;
}*/

void tsStart(const char* path) {
    sSetPrinter(tsPrinter);
    doneTests = 0;
    allTests = 0;
    tsAppend(path);
    tsScanDirectory();
    printf("%d / %d tests succeeded\n", doneTests, allTests);
}