/*
 * LLM Proxy Client - C Version (Windows using curl.exe)
 * Compile: gcc -std=c11 -O2 -Wall -Wextra -o llm_client_curl.exe client_curl.c
 * Usage: llm_client_curl.exe
 * Requires curl.exe, included with current Windows 10 and Windows 11.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>

#define MAX_PROMPT_SIZE 4096
#define MAX_RESPONSE_SIZE 65536

typedef struct {
    const char *name;
    const char *id;
} LLMModel;

static const LLMModel MODELS[] = {
    {"Laguna S 2.1 (Free)", "poolside/laguna-s-2.1:free"},
    {"Gemini 3.6 Flash (Paid)", "google/gemini-3.6-flash"},
    {"Claude Opus 5 (Paid)", "anthropic/claude-opus-5"},
    {"Claude Fable 5 (Paid)", "anthropic/claude-fable-5"},
    {"GPT-5.6 Sol (Paid)", "openai/gpt-5.6-sol"},
    {"GPT-5.6 Luna (Paid)", "openai/gpt-5.6-luna"},
    {"Nemotron 3 Ultra (Free)", "nvidia/nemotron-3-ultra-550b-a55b:free"}
};

static const int MODEL_COUNT = sizeof(MODELS) / sizeof(MODELS[0]);

static char *copy_string(const char *text) {
    size_t size = strlen(text) + 1;
    char *copy = (char *)malloc(size);
    if (copy != NULL) {
        memcpy(copy, text, size);
    }
    return copy;
}

static char *error_message(const char *message, DWORD code) {
    char buffer[256];
    snprintf(buffer, sizeof(buffer), "Error: %s (code: %lu)", message, (unsigned long)code);
    return copy_string(buffer);
}

static int create_temp_file(char *path) {
    char temp_dir[MAX_PATH];
    DWORD length = GetTempPathA(sizeof(temp_dir), temp_dir);
    if (length == 0 || length >= sizeof(temp_dir)) {
        return 0;
    }
    return GetTempFileNameA(temp_dir, "llm", 0, path) != 0;
}

static int write_binary_file(const char *path, const char *data, size_t size) {
    FILE *file = fopen(path, "wb");
    if (file == NULL) {
        return 0;
    }
    int success = fwrite(data, 1, size, file) == size;
    if (fclose(file) != 0) {
        success = 0;
    }
    return success;
}

static char *read_response_file(const char *path) {
    FILE *file = fopen(path, "rb");
    if (file == NULL) {
        return copy_string("Error: Failed to read curl response");
    }

    char *response = (char *)malloc(MAX_RESPONSE_SIZE);
    if (response == NULL) {
        fclose(file);
        return copy_string("Error: Memory allocation failed");
    }

    size_t total_size = fread(response, 1, MAX_RESPONSE_SIZE - 1, file);
    if (ferror(file)) {
        free(response);
        fclose(file);
        return copy_string("Error: Failed while reading curl response");
    }
    response[total_size] = '\0';
    fclose(file);
    return response;
}

char *ask_llm(const char *prompt, const LLMModel *model) {
    char request_path[MAX_PATH] = {0};
    char response_path[MAX_PATH] = {0};
    char command[2048];
    STARTUPINFOA startup_info;
    PROCESS_INFORMATION process_info;
    DWORD exit_code = 0;
    char *response = NULL;

    if (!create_temp_file(request_path) || !create_temp_file(response_path)) {
        response = error_message("Failed to create temporary files", GetLastError());
        goto cleanup;
    }

    if (!write_binary_file(request_path, prompt, strlen(prompt))) {
        response = copy_string("Error: Failed to write temporary request file");
        goto cleanup;
    }

    int command_length = snprintf(
        command,
        sizeof(command),
        "curl.exe --silent --show-error --fail-with-body --connect-timeout 30 "
        "--max-time 120 --request POST --header \"Content-Type: text/plain; charset=utf-8\" "
        "--header \"X-Model: %s\" --data-binary \"@%s\" --output \"%s\" "
        "https://ttl0110-llm-proxy.hf.space/ask",
        model->id,
        request_path,
        response_path);
    if (command_length < 0 || command_length >= (int)sizeof(command)) {
        response = copy_string("Error: curl command is too long");
        goto cleanup;
    }

    ZeroMemory(&startup_info, sizeof(startup_info));
    ZeroMemory(&process_info, sizeof(process_info));
    startup_info.cb = sizeof(startup_info);

    if (!CreateProcessA(
            NULL,
            command,
            NULL,
            NULL,
            FALSE,
            CREATE_NO_WINDOW,
            NULL,
            NULL,
            &startup_info,
            &process_info)) {
        response = error_message("Failed to start curl.exe", GetLastError());
        goto cleanup;
    }

    WaitForSingleObject(process_info.hProcess, INFINITE);
    if (!GetExitCodeProcess(process_info.hProcess, &exit_code)) {
        response = error_message("Failed to read curl exit code", GetLastError());
    }
    CloseHandle(process_info.hThread);
    CloseHandle(process_info.hProcess);

    if (response == NULL) {
        response = read_response_file(response_path);
    }
    if (exit_code != 0 && response != NULL && response[0] == '\0') {
        free(response);
        response = error_message("curl.exe request failed", exit_code);
    }

cleanup:
    if (request_path[0] != '\0') {
        DeleteFileA(request_path);
    }
    if (response_path[0] != '\0') {
        DeleteFileA(response_path);
    }
    return response != NULL ? response : copy_string("Error: Unknown request failure");
}

void clear_input_buffer(void) {
    int c;
    while ((c = getchar()) != '\n' && c != EOF);
}

int main(void) {
    char prompt[MAX_PROMPT_SIZE];
    char prompt_prefix[MAX_PROMPT_SIZE] = {0};
    int choice = 0;

    SetConsoleOutputCP(CP_UTF8);
    SetConsoleCP(CP_UTF8);

    printf("=== C LLM Assistant (curl.exe) ===\n\n");
    printf("Chon Model LLM:\n");
    for (int i = 0; i < MODEL_COUNT; i++) {
        printf("%d. %s\n", i + 1, MODELS[i].name);
    }

    while (choice < 1 || choice > MODEL_COUNT) {
        printf("Nhap lua chon (1-%d): ", MODEL_COUNT);
        if (scanf("%d", &choice) != 1) {
            clear_input_buffer();
            choice = 0;
        }
    }
    clear_input_buffer();

    const LLMModel *selected_model = &MODELS[choice - 1];
    printf("Ban da chon: %s\n\n", selected_model->name);

    printf("Nhap prompt prefix (bo trong neu khong dung): ");
    if (fgets(prompt_prefix, sizeof(prompt_prefix), stdin) != NULL) {
        prompt_prefix[strcspn(prompt_prefix, "\r\n")] = '\0';
    }

    printf("Huong dan: Nhap prompt cua ban. Nhap dong trong de gui.\n");
    printf("Nhap 'EXIT' de thoat.\n");

    while (1) {
        char full_prompt[MAX_PROMPT_SIZE] = {0};
        size_t total_len = 0;

        printf("\nBan [%s]:\n", selected_model->name);
        while (1) {
            if (fgets(prompt, sizeof(prompt), stdin) == NULL) {
                printf("Tam biet!\n");
                return 0;
            }
            if (_strnicmp(prompt, "EXIT", 4) == 0 &&
                (prompt[4] == '\n' || prompt[4] == '\r' || prompt[4] == '\0')) {
                printf("Tam biet!\n");
                return 0;
            }
            if (prompt[0] == '\n' || (prompt[0] == '\r' && prompt[1] == '\n')) {
                break;
            }

            size_t line_len = strlen(prompt);
            if (total_len + line_len < MAX_PROMPT_SIZE - 1) {
                strcat(full_prompt, prompt);
                total_len += line_len;
            }
        }

        if (total_len == 0) {
            printf("Prompt trong, vui long nhap lai.\n");
            continue;
        }
        while (total_len > 0 &&
               (full_prompt[total_len - 1] == '\n' || full_prompt[total_len - 1] == '\r')) {
            full_prompt[--total_len] = '\0';
        }

        char request_prompt[MAX_PROMPT_SIZE] = {0};
        if (prompt_prefix[0] != '\0') {
            int written = snprintf(request_prompt, sizeof(request_prompt), "%s\n\n%s",
                                   prompt_prefix, full_prompt);
            if (written < 0 || written >= (int)sizeof(request_prompt)) {
                printf("Prompt va prefix qua dai, vui long nhap lai.\n");
                continue;
            }
        } else {
            strcpy(request_prompt, full_prompt);
        }

        printf("Thinking...\n");
        char *response = ask_llm(request_prompt, selected_model);
        printf("\n[LLM]: %s\n", response);
        printf("-------------------------------------------\n");
        free(response);
    }
}