//#define PCILIB_FILE_IO
#define _XOPEN_SOURCE 700
#define _BSD_SOURCE
#define _DEFAULT_SOURCE
#define _POSIX_C_SOURCE 200809L

#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <stdint.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <errno.h>
#include <assert.h>

#include "pcilib.h"
#include "pci.h"
#include "tools.h"
#include "error.h"
#include "model.h"
#include "plugin.h"
#include "bar.h"
#include "xml.h"
#include "locking.h"

static int pcilib_detect_model(pcilib_t *ctx, const char *model) {
    int i, j;

    const pcilib_model_description_t *model_info = NULL;
    const pcilib_board_info_t *board_info = pcilib_get_board_info(ctx);

    model_info = pcilib_find_plugin_model(ctx, board_info->vendor_id, board_info->device_id, model);
    if (model_info) {
	memcpy(&ctx->model_info, model_info, sizeof(pcilib_model_description_t));
	memcpy(&ctx->dma, model_info->dma, sizeof(pcilib_dma_description_t));
	ctx->model = strdup(model_info->name);
    } else if (model) {
	    // If not found, check for DMA models
	for (i = 0; pcilib_dma[i].name; i++) {
	    if (!strcasecmp(model, pcilib_dma[i].name))
		break;
	}

	if (pcilib_dma[i].api) {
	    model_info = &ctx->model_info;
	    memcpy(&ctx->dma, &pcilib_dma[i], sizeof(pcilib_dma_description_t));
	    ctx->model_info.dma = &ctx->dma;
	}
    }

	    // Precedens of register configuration: DMA/Event Initialization (top), XML, Event Description, DMA Description (least)
    if (model_info) {
	const pcilib_dma_description_t *dma = model_info->dma;

	if (dma) {
	    if (dma->banks)
		pcilib_add_register_banks(ctx, PCILIB_MODEL_MODIFICATON_FLAGS_DEFAULT, 0, dma->banks, NULL);

	    if (dma->registers)
		pcilib_add_registers(ctx, PCILIB_MODEL_MODIFICATON_FLAGS_DEFAULT, 0, dma->registers, NULL);

	    if (dma->engines) {
		for (j = 0; dma->engines[j].addr_bits; j++);
		memcpy(ctx->engines, dma->engines, j * sizeof(pcilib_dma_engine_description_t));
		ctx->num_engines = j;
	    } else
		ctx->dma.engines = ctx->engines;
	}

	if (model_info->protocols)
	    pcilib_add_register_protocols(ctx, PCILIB_MODEL_MODIFICATON_FLAGS_DEFAULT, 0, model_info->protocols, NULL);
		
	if (model_info->banks)
	    pcilib_add_register_banks(ctx, PCILIB_MODEL_MODIFICATON_FLAGS_DEFAULT, 0, model_info->banks, NULL);

	if (model_info->registers)
	    pcilib_add_registers(ctx, PCILIB_MODEL_MODIFICATON_FLAGS_DEFAULT, 0, model_info->registers, NULL);
		
	if (model_info->ranges)
	    pcilib_add_register_ranges(ctx, PCILIB_MODEL_MODIFICATON_FLAGS_DEFAULT, 0, model_info->ranges);
    }

    // Load XML registers

    // Check for all installed models
    // memcpy(&ctx->model_info, model, sizeof(pcilib_model_description_t));
    // how we reconcile the banks from event model and dma description? The banks specified in the DMA description should override corresponding banks of events...


    if (!model_info) {
	if ((model)&&(strcasecmp(model, "pci"))/*&&(no xml)*/)
	    return PCILIB_ERROR_NOTFOUND;
	
	ctx->model = strdup("pci");
    }

    return 0;
}



pcilib_t *pcilib_open(const char *device, const char *model) {
    int err, xmlerr;
    size_t i;
    pcilib_t *ctx = malloc(sizeof(pcilib_t));
	
    if (!model)
	model = getenv("PCILIB_MODEL");

    if (ctx) {
	memset(ctx, 0, sizeof(pcilib_t));
	ctx->pci_cfg_space_fd = -1;
	
	ctx->handle = open(device, O_RDWR);
	if (ctx->handle < 0) {
	    pcilib_error("Error opening device (%s)", device);
	    free(ctx);
	    return NULL;
	}
	
	ctx->page_mask = (uintptr_t)-1;
	
	if ((model)&&(!strcasecmp(model, "maintenance"))) {
	    ctx->model = strdup("maintenance");
	    return ctx;
	}

	err = pcilib_init_locking(ctx);
	if (err) {
	    pcilib_error("Error (%i) initializing locking subsystem", err);
	    pcilib_close(ctx);
	    return NULL;
	}

	ctx->alloc_reg = PCILIB_DEFAULT_REGISTER_SPACE;
	ctx->alloc_views=PCILIB_DEFAULT_VIEW_SPACE;
	ctx->registers = (pcilib_register_description_t *)malloc(PCILIB_DEFAULT_REGISTER_SPACE * sizeof(pcilib_register_description_t));
	ctx->register_ctx = (pcilib_register_context_t *)malloc(PCILIB_DEFAULT_REGISTER_SPACE * sizeof(pcilib_register_context_t));
	ctx->views = (pcilib_view_t*)malloc(PCILIB_DEFAULT_VIEW_SPACE * sizeof(pcilib_view_t));
	ctx->alloc_units=PCILIB_DEFAULT_UNIT_SPACE;
	ctx->units=(pcilib_unit_t*)malloc(PCILIB_DEFAULT_UNIT_SPACE * sizeof(pcilib_unit_t));
	
	if ((!ctx->registers)||(!ctx->register_ctx)) {
	    pcilib_error("Error allocating memory for register model");
	    pcilib_close(ctx);
	    return NULL;
	}
	
	/* i think we need a better error handling here, because, it's not that a problem to not have views working, but how to block the use if the memory here was not good?, and we could have only one type of views that is working*/
	if((!ctx->units) || !(ctx->views)){
	  pcilib_warning("Error allocating memory for views");
	}

	
	
	memset(ctx->registers, 0, sizeof(pcilib_register_description_t));
	memset(ctx->banks, 0, sizeof(pcilib_register_bank_description_t));
	memset(ctx->ranges, 0, sizeof(pcilib_register_range_t));

	memset(ctx->register_ctx, 0, PCILIB_DEFAULT_REGISTER_SPACE * sizeof(pcilib_register_context_t));

	memset(ctx->units,0,sizeof(pcilib_unit_t));
	memset(ctx->views,0,sizeof(pcilib_view_t));
	
	for (i = 0; pcilib_protocols[i].api; i++);
	memcpy(ctx->protocols, pcilib_protocols, i * sizeof(pcilib_register_protocol_description_t));
	ctx->num_protocols = i;

	err = pcilib_detect_model(ctx, model);
	if ((err)&&(err != PCILIB_ERROR_NOTFOUND)) {
	    const pcilib_board_info_t *board_info = pcilib_get_board_info(ctx);
	    if (board_info)
	        pcilib_error("Error (%i) configuring model %s (%x:%x)", err, (model?model:""), board_info->vendor_id, board_info->device_id);
	    else
	        pcilib_error("Error (%i) configuring model %s", err, (model?model:""));
	    pcilib_close(ctx);
	    return NULL;
	}

	if (!ctx->model)
	    ctx->model = strdup(model?model:"pci");
	
	xmlerr = pcilib_init_xml(ctx, ctx->model);
	if ((xmlerr)&&(xmlerr != PCILIB_ERROR_NOTFOUND)) {
	    pcilib_error("Error (%i) initializing XML subsystem for model %s", xmlerr, ctx->model);
	    pcilib_close(ctx);
	    return NULL;
	}

	    // We have found neither standard model nor XML
	if ((err)&&(xmlerr)) {
	    pcilib_error("The specified model (%s) is not available", model);
	    pcilib_close(ctx);
	    return NULL;
	}
	
	ctx->model_info.registers = ctx->registers;
	ctx->model_info.banks = ctx->banks;
	ctx->model_info.protocols = ctx->protocols;
	ctx->model_info.ranges = ctx->ranges;

	err = pcilib_init_register_banks(ctx);
	if (err) {
	    pcilib_error("Error (%i) initializing regiser banks\n", err);
	    pcilib_close(ctx);
	    return NULL;
	}
	
	err = pcilib_init_event_engine(ctx);
	if (err) {
	    pcilib_error("Error (%i) initializing event engine\n", err);
	    pcilib_close(ctx);
	    return NULL;
	}
    }

    return ctx;
}


const pcilib_board_info_t *pcilib_get_board_info(pcilib_t *ctx) {
    int ret;
    
    if (ctx->page_mask ==  (uintptr_t)-1) {
	ret = ioctl( ctx->handle, PCIDRIVER_IOC_PCI_INFO, &ctx->board_info );
	if (ret) {
	    pcilib_error("PCIDRIVER_IOC_PCI_INFO ioctl have failed");
	    return NULL;
	}
	
	ctx->page_mask = pcilib_get_page_mask();
    }
    
    return &ctx->board_info;
}


pcilib_context_t *pcilib_get_implementation_context(pcilib_t *ctx) {
    return ctx->event_ctx;
}


int pcilib_map_data_space(pcilib_t *ctx, uintptr_t addr) {
    int err;
    pcilib_bar_t i;
    
    if (!ctx->data_bar_mapped) {
        const pcilib_board_info_t *board_info = pcilib_get_board_info(ctx);
	if (!board_info) return PCILIB_ERROR_FAILED;

	err = pcilib_map_register_space(ctx);
	if (err) {
	    pcilib_error("Error mapping register space");
	    return err;
	}
	
	int data_bar = -1;
	
	for (i = 0; i < PCILIB_MAX_BARS; i++) {
	    if ((ctx->bar_space[i])||(!board_info->bar_length[i])) continue;
	    
	    if (addr) {
	        if (board_info->bar_start[i] == addr) {
		    data_bar = i;
		    break;
		}
	    } else {
		if (data_bar >= 0) {
		    data_bar = -1;
		    break;
		}
		
		data_bar = i;
	    }
	}
	    

	if (data_bar < 0) {
	    if (addr) pcilib_error("Unable to find the specified data space (%lx)", addr);
	    else pcilib_error("Unable to find the data space");
	    return PCILIB_ERROR_NOTFOUND;
	}
	
	ctx->data_bar = data_bar;
	
	if (!ctx->bar_space[data_bar]) {
	    char *data_space = pcilib_map_bar(ctx, data_bar);
	    if (data_space) ctx->bar_space[data_bar] = data_space;
	    else {
	        pcilib_error("Unable to map the data space");
		return PCILIB_ERROR_FAILED;
	    }
	}
	
	ctx->data_bar_mapped = 0;
    }
    
    return 0;
}
	
char *pcilib_resolve_register_address(pcilib_t *ctx, pcilib_bar_t bar, uintptr_t addr) {
    if (bar == PCILIB_BAR_DETECT) {
	    // First checking the default register bar
	size_t offset = addr - ctx->board_info.bar_start[ctx->reg_bar];
	if ((addr > ctx->board_info.bar_start[ctx->reg_bar])&&(offset < ctx->board_info.bar_length[ctx->reg_bar])) {
	    if (!ctx->bar_space[ctx->reg_bar]) {
		pcilib_error("The register bar is not mapped");
		return NULL;
	    }

	    return ctx->bar_space[ctx->reg_bar] + offset + (ctx->board_info.bar_start[ctx->reg_bar] & ctx->page_mask);
	}
	    
	    // Otherwise trying to detect
	bar = pcilib_detect_bar(ctx, addr, 1);
	if (bar != PCILIB_BAR_INVALID) {
	    size_t offset = addr - ctx->board_info.bar_start[bar];
	    if ((offset < ctx->board_info.bar_length[bar])&&(ctx->bar_space[bar])) {
		if (!ctx->bar_space[bar]) {
		    pcilib_error("The requested bar (%i) is not mapped", bar);
		    return NULL;
		}
		return ctx->bar_space[bar] + offset + (ctx->board_info.bar_start[bar] & ctx->page_mask);
	    }
	}
    } else {
	if (!ctx->bar_space[bar]) {
	    pcilib_error("The requested bar (%i) is not mapped", bar);
	    return NULL;
	}
	
	if (addr < ctx->board_info.bar_length[bar]) {
	    return ctx->bar_space[bar] + addr + (ctx->board_info.bar_start[bar] & ctx->page_mask);
	}
	
	if ((addr >= ctx->board_info.bar_start[bar])&&(addr < (ctx->board_info.bar_start[bar] + ctx->board_info.bar_length[ctx->reg_bar]))) {
	    return ctx->bar_space[bar] + (addr - ctx->board_info.bar_start[bar]) + (ctx->board_info.bar_start[bar] & ctx->page_mask);
	}
    }

    return NULL;
}

char *pcilib_resolve_data_space(pcilib_t *ctx, uintptr_t addr, size_t *size) {
    int err;
    
    err = pcilib_map_data_space(ctx, addr);
    if (err) {
	pcilib_error("Failed to map the specified address space (%lx)", addr);
	return NULL;
    }
    
    if (size) *size = ctx->board_info.bar_length[ctx->data_bar];
    
    return ctx->bar_space[ctx->data_bar] + (ctx->board_info.bar_start[ctx->data_bar] & ctx->page_mask);
}


void pcilib_close(pcilib_t *ctx) {
    pcilib_bar_t i;

    if (ctx) {
	pcilib_dma_engine_t dma;
	const pcilib_model_description_t *model_info = pcilib_get_model_description(ctx);
	const pcilib_event_api_description_t *eapi = model_info->api;
	const pcilib_dma_api_description_t *dapi = ctx->dma.api;
	
        if ((eapi)&&(eapi->free)) eapi->free(ctx->event_ctx);
        if ((dapi)&&(dapi->free)) dapi->free(ctx->dma_ctx);

	for  (dma = 0; dma < PCILIB_MAX_DMA_ENGINES; dma++) {
	    if (ctx->dma_rlock[dma])
		pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, ctx->dma_rlock[dma]);
	    if (ctx->dma_wlock[dma])
		pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, ctx->dma_wlock[dma]);
	}

	pcilib_free_register_banks(ctx);

	pcilib_free_xml(ctx);
	
	if (ctx->register_ctx)
	    free(ctx->register_ctx);

	if (ctx->event_plugin)
	    pcilib_plugin_close(ctx->event_plugin);

	if (ctx->locks.kmem)
	    pcilib_free_locking(ctx);

	if (ctx->kmem_list) {
	    pcilib_warning("Not all kernel buffers are properly cleaned");
	
	    while (ctx->kmem_list) {
		pcilib_free_kernel_memory(ctx, ctx->kmem_list, 0);
	    }
	}
	
	for (i = 0; i < PCILIB_MAX_BARS; i++) {
	    if (ctx->bar_space[i]) {
		char *ptr = ctx->bar_space[i];
		ctx->bar_space[i] = NULL;
		pcilib_unmap_bar(ctx, i, ptr);
	    }
	}
	
	if (ctx->pci_cfg_space_fd >= 0)
	    close(ctx->pci_cfg_space_fd);

	if (ctx->registers)
	    free(ctx->registers);
	
	if (ctx->model)
	    free(ctx->model);

	if (ctx->handle >= 0)
	    close(ctx->handle);
	
	free(ctx);
    }
}

static int pcilib_update_pci_configuration_space(pcilib_t *ctx) {
    int err;
    int size;

    if (ctx->pci_cfg_space_fd < 0) {
	char fname[128];

	const pcilib_board_info_t *board_info = pcilib_get_board_info(ctx);
	if (!board_info) {
	    pcilib_error("Failed to acquire board info");
	    return PCILIB_ERROR_FAILED;
	}

	sprintf(fname, "/sys/bus/pci/devices/0000:%02x:%02x.%1x/config", board_info->bus, board_info->slot, board_info->func);

	ctx->pci_cfg_space_fd = open(fname, O_RDONLY);
	if (ctx->pci_cfg_space_fd < 0) {
	    pcilib_error("Failed to open configuration space in %s", fname);
	    return PCILIB_ERROR_FAILED;
	}
    } else {
	err = lseek(ctx->pci_cfg_space_fd, SEEK_SET, 0);
	if (err) {
	    close(ctx->pci_cfg_space_fd);
	    ctx->pci_cfg_space_fd = -1;
	    return pcilib_update_pci_configuration_space(ctx);
	}
    }

    size = read(ctx->pci_cfg_space_fd, ctx->pci_cfg_space_cache, 256);
    if (size < 64) {
	if (size <= 0)
	    pcilib_error("Failed to read PCI configuration from sysfs, errno: %i", errno);
	else
	    pcilib_error("Failed to read PCI configuration from sysfs, only %zu bytes read (expected at least 64)", size);
	return PCILIB_ERROR_FAILED;
    }

    ctx->pci_cfg_space_size = size;

    return 0;
}


static uint32_t *pcilib_get_pci_capabilities(pcilib_t *ctx, int cap_id) {
    int err;

    uint32_t cap;
    uint8_t cap_offset;		/**< Offset of capability in the configuration space */

    if (!ctx->pci_cfg_space_fd) {
	err = pcilib_update_pci_configuration_space(ctx);
	if (err) {
	    pcilib_error("Error (%i) reading PCI configuration space", err);
	    return NULL;
	}
    }

	// This is just a pointer to the first cap
    cap = ctx->pci_cfg_space_cache[(0x34>>2)];
    cap_offset = cap&0xFC;

    while ((cap_offset)&&(cap_offset < ctx->pci_cfg_space_size)) {
	cap = ctx->pci_cfg_space_cache[cap_offset>>2];
	if ((cap&0xFF) == cap_id)
	    return &ctx->pci_cfg_space_cache[cap_offset>>2];
	cap_offset = (cap>>8)&0xFC;
    }

    return NULL;
};


static const uint32_t *pcilib_get_pcie_capabilities(pcilib_t *ctx) {
    if (ctx->pcie_capabilities)
	return ctx->pcie_capabilities;

    ctx->pcie_capabilities = pcilib_get_pci_capabilities(ctx, 0x10);
    return ctx->pcie_capabilities;
}


const pcilib_pcie_link_info_t *pcilib_get_pcie_link_info(pcilib_t *ctx) {
    int err;
    const uint32_t *cap;

    err = pcilib_update_pci_configuration_space(ctx);
    if (err) {
	pcilib_error("Error (%i) updating PCI configuration space", err);
	return NULL;
    }

    cap = pcilib_get_pcie_capabilities(ctx);
    if (!cap) return NULL;

	// Generally speaking this can be updated during the application life time
    
    ctx->link_info.max_payload = (cap[1] & 0x07) + 7;
    ctx->link_info.payload = ((cap[2] >> 5) & 0x07) + 7;
    ctx->link_info.link_speed = (cap[3]&0xF);
    ctx->link_info.link_width = (cap[3]&0x3F0) >> 4;
    ctx->link_info.max_link_speed = (cap[4]&0xF0000) >> 16;
    ctx->link_info.max_link_width = (cap[4]&0x3F00000) >> 20;

    return &ctx->link_info;
}