// test_routing_mesh.c - Test routing between 3 instances in mesh topology
// Based on test_etcp_two_instances.c approach - using config files

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "test_utils.h"
#include "../lib/platform_compat.h"
#include "../src/etcp.h"
#include "../src/etcp_connections.h"
#include "../src/config_parser.h"
#include "../src/utun_instance.h"
#include "../src/routing.h"
#include "../src/tun_if.h"
#include "../src/secure_channel.h"
#include "../lib/u_async.h"
#include "../lib/debug_config.h"

#define TEST_TIMEOUT_MS 10000   // 10 seconds timeout

// Keys from test_etcp_two_instances.c (known working keys)
// Instance A keys
#define KEY_A_PRIV "67b705a92b41bcaae105af2d6a17743faa7b26ccebba8b3b9b0af05e9cd1d5fb"
#define KEY_A_PUB  "1c55e4ccae7c4470707759086738b10681bf88b81f198cc2ab54a647d1556e17c65e6b1833e0c771e5a39382c03067c388915a4c732191bc130480f20f8e00b9"

// Instance B keys  
#define KEY_B_PRIV "4813d31d28b7e9829247f488c6be7672f2bdf61b2508333128e386d1759afed2"
#define KEY_B_PUB  "c594f33c91f3a2222795c2c110c527bf214ad1009197ce14556cb13df3c461b3c373bed8f205a8dd1fc0c364f90bf471d7c6f5db49564c33e4235d268569ac71"

// Instance C keys (need valid keys - generate them)
static char key_c_priv[65];
static char key_c_pub[129];

static struct UTUN_INSTANCE* inst_a = NULL;
static struct UTUN_INSTANCE* inst_b = NULL;
static struct UTUN_INSTANCE* inst_c = NULL;
static struct UASYNC* ua = NULL;
static int test_phase = 0;
static void* timeout_id = NULL;

static char temp_dir[] = "/tmp/utun_mesh_test_XXXXXX";
static char config_a[256], config_b[256], config_c[256];

// Config A: servers for B and C to connect to
static const char* config_a_content =
    "[global]\n"
    "my_node_id=0xAAAAAAAAAAAAAAAA\n"
    "my_private_key=" KEY_A_PRIV "\n"
    "my_public_key=" KEY_A_PUB "\n"
    "tun_ip=10.99.1.1/24\n"
    "tun_ifname=tun_a\n"
    "tun_test_mode=1\n"
    "\n"
    "[routing]\n"
    "my_subnet=192.168.10.0/24\n"
    "my_subnet=192.168.11.0/24\n"
    "\n"
    "[server: b]\n"
    "addr=127.0.0.1:9101\n"
    "type=public\n"
    "\n"
    "[server: c]\n"
    "addr=127.0.0.1:9102\n"
    "type=public\n";

// Config B: servers for A and C to connect to  
static const char* config_b_content =
    "[global]\n"
    "my_node_id=0xBBBBBBBBBBBBBBBB\n"
    "my_private_key=" KEY_B_PRIV "\n"
    "my_public_key=" KEY_B_PUB "\n"
    "tun_ip=10.99.2.1/24\n"
    "tun_ifname=tun_b\n"
    "tun_test_mode=1\n"
    "\n"
    "[routing]\n"
    "my_subnet=192.168.20.0/24\n"
    "my_subnet=192.168.21.0/24\n"
    "\n"
    "[server: a]\n"
    "addr=127.0.0.1:9201\n"
    "type=public\n"
    "\n"
    "[server: c]\n"
    "addr=127.0.0.1:9202\n"
    "type=public\n";

// Config C: servers for A and B to connect to
static const char* config_c_content_template =
    "[global]\n"
    "my_node_id=0xCCCCCCCCCCCCCCCC\n"
    "my_private_key=%s\n"
    "my_public_key=%s\n"
    "tun_ip=10.99.3.1/24\n"
    "tun_ifname=tun_c\n"
    "tun_test_mode=1\n"
    "\n"
    "[routing]\n"
    "my_subnet=192.168.30.0/24\n"
    "my_subnet=192.168.31.0/24\n"
    "\n"
    "[server: a]\n"
    "addr=127.0.0.1:9302\n"
    "type=public\n"
    "\n"
    "[server: b]\n"
    "addr=127.0.0.1:9303\n"
    "type=public\n";

// Client sections to add to configs for mesh topology
static const char* client_a_content =
    "\n[client: to_b]\n"
    "keepalive=1\n"
    "peer_public_key=" KEY_B_PUB "\n"
    "link=b:127.0.0.1:9201\n"
    "\n[client: to_c]\n"
    "keepalive=1\n"
    "peer_public_key=%s\n"  // Will be filled with C's key
    "link=c:127.0.0.1:9302\n";

static const char* client_b_content =
    "\n[client: to_a]\n"
    "keepalive=1\n"
    "peer_public_key=" KEY_A_PUB "\n"
    "link=a:127.0.0.1:9101\n"
    "\n[client: to_c]\n"
    "keepalive=1\n"
    "peer_public_key=%s\n"  // Will be filled with C's key
    "link=c:127.0.0.1:9303\n";

static const char* client_c_content_template =
    "\n[client: to_a]\n"
    "keepalive=1\n"
    "peer_public_key=" KEY_A_PUB "\n"
    "link=a:127.0.0.1:9102\n"
    "\n[client: to_b]\n"
    "keepalive=1\n"
    "peer_public_key=" KEY_B_PUB "\n"
    "link=b:127.0.0.1:9202\n";

static int create_temp_configs(void) {
    if (test_mkdtemp(temp_dir) != 0) {
        fprintf(stderr, "Failed to create temp directory\n");
        return -1;
    }
    
    snprintf(config_a, sizeof(config_a), "%s/a.conf", temp_dir);
    snprintf(config_b, sizeof(config_b), "%s/b.conf", temp_dir);
    snprintf(config_c, sizeof(config_c), "%s/c.conf", temp_dir);
    
    // Generate keys for C
    struct SC_MYKEYS keys_c;
    if (sc_generate_keypair(&keys_c) != SC_OK) {
        fprintf(stderr, "Failed to generate keys for C\n");
        return -1;
    }
    
    // Convert to hex
    const char* hex_chars = "0123456789abcdef";
    for (int i = 0; i < 32; i++) {
        key_c_priv[i*2] = hex_chars[(keys_c.private_key[i] >> 4) & 0xF];
        key_c_priv[i*2+1] = hex_chars[keys_c.private_key[i] & 0xF];
    }
    key_c_priv[64] = '\0';
    
    for (int i = 0; i < 64; i++) {
        key_c_pub[i*2] = hex_chars[(keys_c.public_key[i] >> 4) & 0xF];
        key_c_pub[i*2+1] = hex_chars[keys_c.public_key[i] & 0xF];
    }
    key_c_pub[128] = '\0';
    
    printf("Generated C keys:\n");
    printf("  priv: %.16s...\n", key_c_priv);
    printf("  pub:  %.16s...\n", key_c_pub);
    
    // Write config A with C's public key
    FILE* f = fopen(config_a, "w");
    if (!f) return -1;
    fprintf(f, "%s", config_a_content);
    fprintf(f, client_a_content, key_c_pub);
    fclose(f);
    
    // Write config B with C's public key
    f = fopen(config_b, "w");
    if (!f) return -1;
    fprintf(f, "%s", config_b_content);
    fprintf(f, client_b_content, key_c_pub);
    fclose(f);
    
    // Write config C with generated keys
    char c_config[4096];
    snprintf(c_config, sizeof(c_config), config_c_content_template, key_c_priv, key_c_pub);
    f = fopen(config_c, "w");
    if (!f) return -1;
    fprintf(f, "%s", c_config);
    fprintf(f, "%s", client_c_content_template);
    fclose(f);
    
    return 0;
}

static void cleanup_temp_configs(void) {
    if (config_a[0]) unlink(config_a);
    if (config_b[0]) unlink(config_b);
    if (config_c[0]) unlink(config_c);
    if (temp_dir[0]) rmdir(temp_dir);
}

static int count_initialized_links(struct UTUN_INSTANCE* inst) {
    int count = 0;
    struct ETCP_CONN* conn = inst->connections;
    while (conn) {
        struct ETCP_LINK* link = conn->links;
        while (link) {
            if (link->initialized) count++;
            link = link->next;
        }
        conn = conn->next;
    }
    return count;
}

static void check_connections(void* arg) {
    (void)arg;
    
    int a = count_initialized_links(inst_a);
    int b = count_initialized_links(inst_b);
    int c = count_initialized_links(inst_c);
    
    printf("[CONNECT] Links ready: A=%d, B=%d, C=%d (need 2 each)\n", a, b, c);
    
    if (a >= 2 && b >= 2 && c >= 2) {
        printf("\n[SUCCESS] All connections established!\n");
        test_phase = 1;
        return;
    }
    
    timeout_id = uasync_set_timeout(ua, 100, NULL, check_connections);
}

static void timeout_handler(void* arg) {
    (void)arg;
    printf("\n[TIMEOUT] Test failed\n");
    test_phase = -1;
}

int main(void) {
    printf("========================================\n");
    printf("  Routing Mesh Test (3 instances)\n");
    printf("========================================\n\n");
    
    if (create_temp_configs() != 0) {
        fprintf(stderr, "Failed to create configs\n");
        return 1;
    }
    
    debug_config_init();
    debug_set_level(DEBUG_LEVEL_WARN);
    
    ua = uasync_create();
    if (!ua) {
        fprintf(stderr, "Failed to create uasync\n");
        return 1;
    }
    
    printf("[INIT] Creating instances from config files...\n");
    
    inst_a = utun_instance_create(ua, config_a);
    inst_b = utun_instance_create(ua, config_b);
    inst_c = utun_instance_create(ua, config_c);
    
    if (!inst_a || !inst_b || !inst_c) {
        fprintf(stderr, "Failed to create instances\n");
        return 1;
    }
    
    printf("  Instance A: node_id=%016llX\n", (unsigned long long)inst_a->node_id);
    printf("  Instance B: node_id=%016llX\n", (unsigned long long)inst_b->node_id);
    printf("  Instance C: node_id=%016llX\n", (unsigned long long)inst_c->node_id);
    
    printf("\n[INIT] Initializing connections...\n");
    
    if (init_connections(inst_a) < 0 ||
        init_connections(inst_b) < 0 ||
        init_connections(inst_c) < 0) {
        fprintf(stderr, "Failed to initialize connections\n");
        return 1;
    }
    
    printf("  Connections initialized\n");
    
    printf("\n[PHASE] Waiting for connections to establish...\n");
    timeout_id = uasync_set_timeout(ua, TEST_TIMEOUT_MS, NULL, timeout_handler);
    check_connections(NULL);
    
    while (test_phase == 0) {
        uasync_poll(ua, 10);
    }
    
    // Cleanup
    if (inst_a) utun_instance_destroy(inst_a);
    if (inst_b) utun_instance_destroy(inst_b);
    if (inst_c) utun_instance_destroy(inst_c);
    if (ua) uasync_destroy(ua, 0);
    cleanup_temp_configs();
    
    if (test_phase == 1) {
        printf("\n✓ TEST PASSED\n");
        return 0;
    } else {
        printf("\n✗ TEST FAILED\n");
        return 1;
    }
}