#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <alloca.h>

#include "pci.h"
#include "pcilib.h"
#include "view.h"
#include "error.h"
#include "value.h"
#include "property.h"

int pcilib_add_views_custom(pcilib_t *ctx, size_t n, const pcilib_view_description_t *desc, pcilib_view_context_t **refs) {
    int err;

    size_t i;
    void *ptr;

    if (!n) {
            // No padding between array elements
        ptr = (void*)desc;
        while (1) {
            const pcilib_view_description_t *v = (const pcilib_view_description_t*)ptr;
            if (v->name) n++;
            else break;
            ptr += v->api->description_size;
        }
    }

    if (!refs) {
        refs = (pcilib_view_context_t**)alloca(n * sizeof(pcilib_view_context_t*));
        if (!refs) return PCILIB_ERROR_MEMORY;
    }

    if ((ctx->num_views + n + 1) > ctx->alloc_views) {
        size_t size;
	pcilib_view_description_t **views;
        for (size = ctx->alloc_views; size < 2 * (n + ctx->num_views + 1); size<<=1);

        views = (pcilib_view_description_t**)realloc(ctx->views, size * sizeof(pcilib_view_description_t*));
        if (!views) return PCILIB_ERROR_MEMORY;

        ctx->views = views;
        ctx->alloc_views = size;

        ctx->model_info.views = (const pcilib_view_description_t**)views;
    }

        // No padding between array elements
    ptr = (void*)desc;
    for (i = 0; i < n; i++) {
        const pcilib_view_description_t *v = (const pcilib_view_description_t*)ptr;
        pcilib_view_description_t *cur;
        pcilib_view_context_t *view_ctx;

        pcilib_view_t view = pcilib_find_view_by_name(ctx, v->name);
        if (view != PCILIB_VIEW_INVALID) {
            ctx->views[ctx->num_views + i] = NULL;
            pcilib_clean_views(ctx, ctx->num_views);
            pcilib_error("View %s is already defined in the model", v->name);
            return PCILIB_ERROR_EXIST;
        }

        cur = (pcilib_view_description_t*)malloc(v->api->description_size);
        if (!cur) {
            ctx->views[ctx->num_views + i] = NULL;
            pcilib_clean_views(ctx, ctx->num_views);
            return PCILIB_ERROR_MEMORY;
        }

        memcpy(cur, v, v->api->description_size);
        ctx->views[ctx->num_views + i] = cur;

        if (v->api->init) 
            view_ctx = v->api->init(ctx, ctx->num_views + i);
        else {
            view_ctx = (pcilib_view_context_t*)malloc(sizeof(pcilib_view_context_t));
            if (view_ctx) memset(view_ctx, 0, sizeof(pcilib_view_context_t));
        }

        if (!view_ctx) {
            free(cur);
            ctx->views[ctx->num_views + i] = NULL;
            pcilib_clean_views(ctx, ctx->num_views);
            return PCILIB_ERROR_FAILED;
        }

	view_ctx->view = ctx->num_views + i;
        view_ctx->name = v->name;

        HASH_ADD_KEYPTR(hh, ctx->view_hash, view_ctx->name, strlen(view_ctx->name), view_ctx);

        if (refs) refs[i] = view_ctx;

        ptr += v->api->description_size;
    }

    ctx->views[ctx->num_views + n] = NULL;

    err = pcilib_add_registers_from_properties(ctx, n, refs, ctx->views + ctx->num_views);
    if (err) {
        pcilib_clean_views(ctx, ctx->num_views);
        return err;
    }

    ctx->num_views += n;

    return 0;
}

int pcilib_add_views(pcilib_t *ctx, size_t n, const pcilib_view_description_t *desc) {
    return pcilib_add_views_custom(ctx, n, desc, NULL);
}


void pcilib_clean_views(pcilib_t *ctx, pcilib_view_t start) {
    pcilib_view_t i;
    pcilib_view_context_t *view_ctx, *tmp;

    if (ctx->view_hash) {
        HASH_ITER(hh, ctx->view_hash, view_ctx, tmp) {
            const pcilib_view_description_t *v = ctx->views[view_ctx->view];

            if (view_ctx->view >= start) {
                HASH_DEL(ctx->view_hash, view_ctx);
                if (v->api->free) v->api->free(ctx, view_ctx);
                else free(view_ctx);
            }
        }
    }

    for (i = start; ctx->views[i]; i++) {
	if (ctx->views[i]->api->free_description) {
	    ctx->views[i]->api->free_description(ctx, ctx->views[i]);
	} else {
	    free(ctx->views[i]);
	}
    }

    ctx->views[start] = NULL;
    ctx->num_views = start;
}

pcilib_view_context_t *pcilib_find_view_context_by_name(pcilib_t *ctx, const char *name) {
    pcilib_view_context_t *view_ctx = NULL;

    HASH_FIND_STR(ctx->view_hash, name, view_ctx);
    return view_ctx;
}

pcilib_view_t pcilib_find_view_by_name(pcilib_t *ctx, const char *name) {
    pcilib_view_context_t *view_ctx = pcilib_find_view_context_by_name(ctx, name);
    if (view_ctx) return view_ctx->view;
    return PCILIB_VIEW_INVALID;
}

pcilib_view_context_t *pcilib_find_register_view_context_by_name(pcilib_t *ctx, pcilib_register_t reg, const char *name) {
    pcilib_view_t i;
    pcilib_register_context_t *regctx = &ctx->register_ctx[reg];

    if (!regctx->views) return NULL;

    for (i = 0; regctx->views[i].name; i++) {
	if (!strcasecmp(name, regctx->views[i].name)) {
	    return pcilib_find_view_context_by_name(ctx, regctx->views[i].view);
	}
    }

    return NULL;
}

    // We expect symmetric units. Therefore, we don't distringuish if we read or write
static int pcilib_detect_register_view_and_unit(pcilib_t *ctx, pcilib_register_t reg, const char *name, int write_direction, pcilib_view_context_t **ret_view, pcilib_unit_transform_t **ret_trans) {
    pcilib_view_t i;
    pcilib_view_context_t *view_ctx;
    pcilib_view_description_t *view_desc;
    pcilib_register_context_t *regctx = &ctx->register_ctx[reg];

    if (!regctx->views) return PCILIB_ERROR_NOTFOUND;

	// Check if view is just a name of listed view
    view_ctx = pcilib_find_register_view_context_by_name(ctx, reg, name);
    if (view_ctx) {
        if (ret_view) *ret_view = view_ctx;
        if (ret_trans) *ret_trans = NULL;
        return 0;
    }

	// Check if view is a unit
    for (i = 0; regctx->views[i].name; i++) {
	pcilib_unit_transform_t *trans;

	view_ctx = pcilib_find_view_context_by_name(ctx, regctx->views[i].view);
	if (!view_ctx) continue;

        view_desc = ctx->views[view_ctx->view];
        if (view_desc->unit) {
            if (write_direction)
	        trans = pcilib_find_transform_by_unit_names(ctx, name, view_desc->unit);
            else
	        trans = pcilib_find_transform_by_unit_names(ctx, view_desc->unit, name);
	    if (trans) {
	        if (ret_trans) *ret_trans = trans;
	        if (ret_view) *ret_view = pcilib_find_view_context_by_name(ctx, view_desc->name);
	        return 0;
	    }
	}
    }

    return PCILIB_ERROR_NOTFOUND;
}

pcilib_view_context_t *pcilib_find_register_view_context(pcilib_t *ctx, pcilib_register_t reg, const char *name) {
    int err;
    pcilib_view_context_t *view;

    err = pcilib_detect_register_view_and_unit(ctx, reg, name, 0, &view, NULL);
    if (err) return NULL;

    return view;
}

typedef struct {
    pcilib_register_t reg;
    pcilib_view_context_t *view;
    pcilib_unit_transform_t *trans;
} pcilib_view_configuration_t;

static int pcilib_detect_view_configuration(pcilib_t *ctx, pcilib_register_t reg, const char *view_cname, const char *unit_cname, int write_direction, pcilib_view_configuration_t *cfg) {
    int err = 0;
    pcilib_view_t view;
    const char *regname;
    pcilib_view_context_t *view_ctx;
    pcilib_unit_transform_t *trans = NULL;

    char *view_name = alloca(strlen(view_cname) + 1);
    const char *unit_name;

    strcpy(view_name, view_cname);

    if (unit_cname) unit_name = unit_cname;
    else {
        unit_name = strchr(view_name, ':');
        if (unit_name) {
	    *(char*)unit_name = 0;
	    unit_name++;
        }
    }

    if (reg == PCILIB_REGISTER_INVALID) regname = NULL;
    else regname = ctx->registers[reg].name;

    if (regname) {
	if (unit_name) view_ctx = pcilib_find_register_view_context_by_name(ctx, reg, view_name);
	else err = pcilib_detect_register_view_and_unit(ctx, reg, view_name, write_direction, &view_ctx, &trans);

	if ((err)||(!view_ctx)) {
	    pcilib_error("Can't find the specified view %s for register %s", view_name, regname);
	    return PCILIB_ERROR_NOTFOUND;
	}
    } else {
        view_ctx = pcilib_find_view_context_by_name(ctx, view_name);
	if (!view_ctx) {
	    pcilib_error("Can't find the specified view %s", view_name);
	    return PCILIB_ERROR_NOTFOUND;
	}
    }
    view = view_ctx->view;

    if (unit_name) {
        if (write_direction) trans = pcilib_find_transform_by_unit_names(ctx, unit_name, ctx->views[view]->unit);
        else trans = pcilib_find_transform_by_unit_names(ctx, ctx->views[view]->unit, unit_name);

        if (!trans) {
            pcilib_error("Don't know how to get the requested unit %s for view %s", unit_name, ctx->views[view]->name);
            return PCILIB_ERROR_NOTFOUND;
        }
    }

        // No transform is required
    if ((trans)&&(!trans->transform)) trans = NULL;

    cfg->reg = reg;
    cfg->view = view_ctx;
    cfg->trans = trans;

    return 0;
}

int pcilib_read_register_view_by_id(pcilib_t *ctx, pcilib_register_t reg, const char *view, pcilib_value_t *val) {
    int err;

    const char *regname;

    pcilib_view_description_t *v;
    pcilib_view_configuration_t cfg;
    pcilib_register_value_t regvalue = 0;

    if (reg == PCILIB_REGISTER_INVALID) regname = NULL;
    else regname = ctx->registers[reg].name;

    err = pcilib_detect_view_configuration(ctx, reg, view, NULL, 0, &cfg);
    if (err) return err;

    v = ctx->views[cfg.view->view];

    if (!v->api->read_from_reg) {
        pcilib_error("The view (%s) does not support reading from the register", view);
        return PCILIB_ERROR_NOTSUPPORTED;
    }

    if ((v->mode & PCILIB_REGISTER_R) == 0) {
        pcilib_error("The view (%s) does not allow reading from the register", view);
        return PCILIB_ERROR_NOTPERMITED;
    }

    if (regname) {
        err = pcilib_read_register_by_id(ctx, cfg.reg, &regvalue);
        if (err) {
            pcilib_error("Error (%i) reading register %s", err, regname);
            return err;
        }
    }

    pcilib_clean_value(ctx, val);

    err = v->api->read_from_reg(ctx, cfg.view, regvalue, val);
    if (err) {
        if (regname) 
            pcilib_error("Error (%i) computing view (%s) of register %s", err, view, regname);
        else
            pcilib_error("Error (%i) computing view %s", err, view);
        return err;
    }

    if (v->unit) {
        val->unit = v->unit;
    }

    if (cfg.trans) {
        err = pcilib_transform_unit(ctx, cfg.trans, val);
        if (err) return err;
    }

    return 0;
}

int pcilib_read_register_view(pcilib_t *ctx, const char *bank, const char *regname, const char *view, pcilib_value_t *val) {
    pcilib_register_t reg;

    if (regname) {
	reg = pcilib_find_register(ctx, bank, regname);
	if (reg == PCILIB_REGISTER_INVALID) {
	    pcilib_error("Register (%s) is not found", regname);
	    return PCILIB_ERROR_NOTFOUND;
	}
    } else {
        reg = PCILIB_REGISTER_INVALID;
    }

    return pcilib_read_register_view_by_id(ctx, reg, view, val);
}


int pcilib_write_register_view_by_id(pcilib_t *ctx, pcilib_register_t reg, const char *view, const pcilib_value_t *valarg) {
    int err;
    pcilib_value_t val = {0};

    const char *regname;

    pcilib_view_description_t *v;
    pcilib_view_configuration_t cfg;
    pcilib_register_value_t regvalue = 0;

    if (reg == PCILIB_REGISTER_INVALID) regname = NULL;
    else regname = ctx->registers[reg].name;

    err = pcilib_detect_view_configuration(ctx, reg, view, valarg->unit, 1, &cfg);
    if (err) return err;

    v = ctx->views[cfg.view->view];

    if (!v->api->write_to_reg) {
        pcilib_error("The view (%s) does not support writting to the register", view);
        return PCILIB_ERROR_NOTSUPPORTED;
    }

    if ((v->mode & PCILIB_REGISTER_W) == 0) {
        pcilib_error("The view (%s) does not allow writting to the register", view);
        return PCILIB_ERROR_NOTPERMITED;
    }

    err = pcilib_copy_value(ctx, &val, valarg);
    if (err) return err;

    err = pcilib_convert_value_type(ctx, &val, v->type);
    if (err) {
        pcilib_error("Error (%i) converting the value of type (%s) to type (%s) used by view (%s)", pcilib_get_type_name(val.type), pcilib_get_type_name(v->type), view);
        return err;
    }

    if (cfg.trans) {
        err = pcilib_transform_unit(ctx, cfg.trans, &val);
        if (err) return err;
    }

    err = v->api->write_to_reg(ctx, cfg.view, &regvalue, &val);
    if (err) {
        if (regname) 
            pcilib_error("Error (%i) computing view (%s) of register %s", err, view, regname);
        else
            pcilib_error("Error (%i) computing view %s", err, view);
        return err;
    }

    if (regname) {
        err = pcilib_write_register_by_id(ctx, cfg.reg, regvalue);
        if (err) {
            pcilib_error("Error (%i) reading register %s", err, regname);
            return err;
        }
    }

    return 0;
}

int pcilib_write_register_view(pcilib_t *ctx, const char *bank, const char *regname, const char *view, const pcilib_value_t *val) {
    pcilib_register_t reg;

    if (regname) {
	reg = pcilib_find_register(ctx, bank, regname);
	if (reg == PCILIB_REGISTER_INVALID) {
	    pcilib_error("Register (%s) is not found", regname);
	    return PCILIB_ERROR_NOTFOUND;
	}
    } else {
        reg = PCILIB_REGISTER_INVALID;
    }

    return pcilib_write_register_view_by_id(ctx, reg, view, val);
}