// Dynamic test runner for every executable in the runner directory.

#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include <string.h>
#include <ntlite/syscall.h>
#include <ntlite/path.h>
#include <ntlite/process_loader.h>

#define ALL_TESTS_INITIAL_CAPACITY 32u

typedef struct TEST_ENTRY {
    char Name[SYS_DIR_NAME_MAX];
} TEST_ENTRY;

static void print(const char* s) {
    SYS_WRITE_CONSOLE_REQUEST req = { sizeof(SYS_WRITE_CONSOLE_REQUEST), SysSvFromCstr(s) };
    SysWriteConsole(&req);
}

static void print_u64(uint64_t v) {
    char buf[32];
    int i = 0;
    if (v == 0) {
        print("0");
        return;
    }
    while (v && i < (int)sizeof(buf)) {
        buf[i++] = (char)('0' + (v % 10));
        v /= 10;
    }
    while (i--) {
        char c[2] = { buf[i], 0 };
        print(c);
    }
}

static void print_i32(int32_t v) {
    if (v < 0) {
        print("-");
        print_u64((uint32_t)(-(v + 1)) + 1u);
        return;
    }
    print_u64((uint32_t)v);
}

static void print_hex32(uint32_t v) {
    static const char hex[] = "0123456789abcdef";
    for (int i = 7; i >= 0; i--) {
        char c[2] = { hex[(v >> (i * 4)) & 0xfu], 0 };
        print(c);
    }
}

// Exits the process without returning to the runtime.
static void exit_now(int code) {
    while (true) SysExitProcess(code);
}

// Converts ASCII to lowercase for stable case-insensitive comparisons.
static char ascii_lower(char c) {
    if (c >= 'A' && c <= 'Z') return (char)(c - 'A' + 'a');
    return c;
}

// Compares two names case-insensitively, with a case-sensitive tie-breaker.
static int compare_names(const char* a, const char* b) {
    size_t i = 0;
    while (true) {
        char ca = ascii_lower(a[i]);
        char cb = ascii_lower(b[i]);
        if (ca != cb) return (unsigned char)ca < (unsigned char)cb ? -1 : 1;
        if (ca == '\0') break;
        i++;
    }
    return strcmp(a, b);
}

// Returns whether one character is a path separator.
static bool is_separator(char c) {
    return c == '/' || c == '\\';
}

// Copies a SYS_STRING_VIEW into a NUL-terminated fixed buffer.
static bool copy_view(char* out, size_t outSize, SYS_STRING_VIEW view) {
    if (!out || outSize == 0 || !view.Data || view.Length + 1 > outSize) return false;
    memcpy(out, view.Data, view.Length);
    out[view.Length] = '\0';
    return true;
}

// Splits an executable path into its directory and basename components.
static bool split_self_path(const char* path, char* dir, size_t dirSize, char* name, size_t nameSize) {
    if (!path || !dir || !name || dirSize == 0 || nameSize == 0) return false;

    size_t len = strlen(path);
    size_t last = (size_t)-1;
    for (size_t i = 0; i < len; i++) {
        if (is_separator(path[i])) last = i;
    }

    const char* base = path;
    size_t dirLen = 1;
    if (last == (size_t)-1) {
        if (dirSize < 2) return false;
        dir[0] = '.';
        dir[1] = '\0';
    } else {
        dirLen = last;
        if (last == 0) dirLen = 1;
        if (last >= 2 && path[1] == ':' && is_separator(path[2])) dirLen = last + 1;
        if (dirLen + 1 > dirSize) return false;
        memcpy(dir, path, dirLen);
        dir[dirLen] = '\0';
        base = path + last + 1;
    }

    size_t baseLen = strlen(base);
    if (baseLen + 1 > nameSize) return false;
    memcpy(name, base, baseLen + 1);
    return true;
}

// Returns whether one filename ends in .exe, case-insensitively.
static bool has_exe_suffix(const char* name) {
    size_t len = strlen(name);
    if (len < 4) return false;
    const char* ext = name + len - 4;
    return ascii_lower(ext[0]) == '.' &&
           ascii_lower(ext[1]) == 'e' &&
           ascii_lower(ext[2]) == 'x' &&
           ascii_lower(ext[3]) == 'e';
}

// Allocates a test-entry array from user VM.
static uint32_t alloc_entries(uint32_t capacity, TEST_ENTRY** entriesOut) {
    void* base = 0;
    size_t bytes = (size_t)capacity * sizeof(TEST_ENTRY);
    size_t pages = (bytes + 4095u) / 4096u;
    if (pages == 0) pages = 1;

    SYS_ALLOC_VM_REQUEST req;
    memset(&req, 0, sizeof(req));
    req.Size = sizeof(req);
    req.Protect = SYS_VM_READWRITE;
    req.Flags = SYS_VM_FLAG_NONE;
    req.PageCount = pages;
    req.BaseOut = &base;

    KSTATUS status = SysAllocVm(&req);
    if (status != NTLSTATUS_SUCCESS || !base) {
        *entriesOut = 0;
        return status ? status : NTLSTATUS_NO_MEMORY;
    }

    *entriesOut = (TEST_ENTRY*)base;
    return NTLSTATUS_SUCCESS;
}

// Grows the test-entry array.
static uint32_t grow_entries(TEST_ENTRY** entries, uint32_t* capacity, uint32_t count) {
    uint32_t oldCapacity = *capacity;
    uint32_t newCapacity = oldCapacity ? oldCapacity * 2u : ALL_TESTS_INITIAL_CAPACITY;
    TEST_ENTRY* next = 0;
    KSTATUS status = alloc_entries(newCapacity, &next);
    if (status != NTLSTATUS_SUCCESS) return status;

    if (*entries && count) memcpy(next, *entries, (size_t)count * sizeof(TEST_ENTRY));
    if (*entries) SysFreeVm(*entries);
    *entries = next;
    *capacity = newCapacity;
    return NTLSTATUS_SUCCESS;
}

// Sorts test entries in deterministic execution order.
static void sort_entries(TEST_ENTRY* entries, uint32_t count) {
    for (uint32_t i = 1; i < count; i++) {
        TEST_ENTRY current = entries[i];
        uint32_t j = i;
        while (j > 0 && compare_names(current.Name, entries[j - 1].Name) < 0) {
            entries[j] = entries[j - 1];
            j--;
        }
        entries[j] = current;
    }
}

// Builds one child path from the runner directory and test filename.
static bool build_child_path(const char* dir, const char* name, char* out, size_t outSize) {
    if (!dir || !name || !out || outSize == 0) return false;
    size_t dirLen = strlen(dir);
    size_t nameLen = strlen(name);
    bool needSep = dirLen > 0 && !is_separator(dir[dirLen - 1]);
    size_t total = dirLen + (needSep ? 1u : 0u) + nameLen;
    if (total + 1 > outSize) return false;

    memcpy(out, dir, dirLen);
    size_t pos = dirLen;
    if (needSep) out[pos++] = '/';
    memcpy(out + pos, name, nameLen);
    out[total] = '\0';
    return true;
}

// Collects executable tests from the runner directory.
static uint32_t collect_tests(const char* dir, const char* selfName, TEST_ENTRY** entriesOut, uint32_t* countOut) {
    *entriesOut = 0;
    *countOut = 0;

    uint32_t hDir = 0;
    KSTATUS status = NtlOpenDir(SysSvFromCstr(dir),
                                 SYS_DIR_ACCESS_ENUMERATE | SYS_DIR_ACCESS_OPEN,
                                 SYS_DIR_FLAG_NONE,
                                 &hDir);
    if (status != NTLSTATUS_SUCCESS) return status;

    TEST_ENTRY* entries = 0;
    uint32_t count = 0;
    uint32_t capacity = 0;

    while (true) {
        SYS_DIR_ENTRY entry;
        status = SysReadDir(hDir, &entry);
        if (status != NTLSTATUS_SUCCESS) break;
        if (!entry.Name[0]) continue;
        if ((entry.Attr & 0x10u) != 0) continue;
        if (!has_exe_suffix(entry.Name)) continue;
        if (compare_names(entry.Name, selfName) == 0) continue;

        if (count == capacity) {
            status = grow_entries(&entries, &capacity, count);
            if (status != NTLSTATUS_SUCCESS) {
                SysCloseHandle(hDir);
                if (entries) SysFreeVm(entries);
                return status;
            }
        }

        strncpy(entries[count].Name, entry.Name, sizeof(entries[count].Name) - 1);
        entries[count].Name[sizeof(entries[count].Name) - 1] = '\0';
        count++;
    }

    SysCloseHandle(hDir);
    sort_entries(entries, count);
    *entriesOut = entries;
    *countOut = count;
    return NTLSTATUS_SUCCESS;
}

// Runs one test process and returns the child's exit code through exitCodeOut.
static uint32_t run_test(const char* path, int32_t* exitCodeOut) {
    uint32_t imageFile = SYS_HANDLE_INVALID;
    KSTATUS status = NtlOpenFile(SysSvFromCstr(path),
                                     SYS_FILE_ACCESS_READ | SYS_FILE_ACCESS_QUERY,
                                     SYS_FILE_OPEN_EXISTING,
                                     SYS_FILE_FLAG_NONE,
                                     &imageFile);
    if (status != NTLSTATUS_SUCCESS) return status;

    uint32_t process = 0;
    NTL_CREATE_SYSTEM_PROCESS_REQUEST req;
    memset(&req, 0, sizeof(req));
    req.Size = sizeof(req);
    req.Flags = NTL_PROCESS_LOAD_FLAG_NONE;
    req.ImageFile = imageFile;
    req.Path = SysSvFromCstr(path);
    req.CommandLine = SysSvFromCstr(path);
    req.SecurityContext = SYS_SECURITY_CONTEXT_CURRENT;
    req.ResolveModuleName = NtlResolveSystemModuleName;
    req.ProcessHandleOut = &process;

    status = NtlCreateSystemProcess(&req);
    (void)SysCloseHandle(imageFile);
    if (status != NTLSTATUS_SUCCESS) return status;

    status = SysWait(process, SYS_WAIT_FLAG_NONE);
    if (status != NTLSTATUS_SUCCESS) {
        SysCloseHandle(process);
        return status;
    }

    int32_t exitCode = 1;
    status = SysGetProcessExitCode(process, &exitCode);
    SysCloseHandle(process);
    if (status != NTLSTATUS_SUCCESS) return status;

    *exitCodeOut = exitCode;
    return NTLSTATUS_SUCCESS;
}

int main(void) {
    print("all_tests: start\n");

    char selfPath[SYS_PATH_MAX];
    char selfDir[SYS_PATH_MAX];
    char selfName[SYS_DIR_NAME_MAX];
    SYS_PEB* peb = SysGetPeb();
    if (!peb || peb->Magic != SYS_PEB_MAGIC || peb->Version != SYS_ENV_VERSION ||
        !copy_view(selfPath, sizeof(selfPath), peb->ImagePath) ||
        !split_self_path(selfPath, selfDir, sizeof(selfDir), selfName, sizeof(selfName))) {
        print("all_tests: failed to resolve runner path\n");
        exit_now(1);
    }

    TEST_ENTRY* entries = 0;
    uint32_t count = 0;
    KSTATUS status = collect_tests(selfDir, selfName, &entries, &count);
    if (status != NTLSTATUS_SUCCESS) {
        print("all_tests: failed to enumerate tests status=0x");
        print_hex32(status);
        print("\n");
        exit_now(1);
    }

    if (count == 0) {
        print("all_tests: no test executables found\n");
        if (entries) SysFreeVm(entries);
        exit_now(1);
    }

    for (uint32_t i = 0; i < count; i++) {
        char childPath[SYS_PATH_MAX];
        if (!build_child_path(selfDir, entries[i].Name, childPath, sizeof(childPath))) {
            print("all_tests: child path too long: ");
            print(entries[i].Name);
            print("\n");
            SysFreeVm(entries);
            exit_now(1);
        }

        print("all_tests: RUN ");
        print(childPath);
        print("\n");

        int32_t exitCode = 1;
        status = run_test(childPath, &exitCode);
        if (status != NTLSTATUS_SUCCESS) {
            print("all_tests: FAIL ");
            print(childPath);
            print(" launch/wait status=0x");
            print_hex32(status);
            print("\n");
            SysFreeVm(entries);
            exit_now(1);
        }

        if (exitCode != 0) {
            print("all_tests: FAIL ");
            print(childPath);
            print(" exit=");
            print_i32(exitCode);
            print("\n");
            SysFreeVm(entries);
            exit_now(exitCode ? exitCode : 1);
        }

        print("all_tests: PASS ");
        print(childPath);
        print("\n");
    }

    print("all_tests: PASS count=");
    print_u64(count);
    print("\n");
    SysFreeVm(entries);
    exit_now(0);
    return 0;
}