#include "printf.h"

#include <blue/core/bstr.h>
#include <blue/core/rope.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define CHECK_FLAG(str, f) ((((str)->bstr_flags) & (f)) == (f))
#define IS_DYNAMIC(p)      (CHECK_FLAG(p, B_BSTR_F_ALLOC))
/* number of bytes that bstr_buf is extended by when required */
#define CAPACITY_STEP      32

void b_bstr_begin(struct b_bstr *str, char *buf, size_t max)
{
	memset(str, 0x0, sizeof *str);

	str->bstr_magic = B_BSTR_MAGIC;
	str->bstr_buf = buf;
	str->bstr_capacity = max;
	str->bstr_len = 0;
	str->bstr_flags = B_BSTR_F_NONE;
}

void b_bstr_begin_dynamic(struct b_bstr *str)
{
	memset(str, 0x0, sizeof *str);

	str->bstr_magic = B_BSTR_MAGIC;
	str->bstr_buf = NULL;
	str->bstr_capacity = 0;
	str->bstr_len = 0;
	str->bstr_flags = B_BSTR_F_ALLOC;
}

static char *truncate_buffer(char *s, size_t len)
{
	if (!s || !len) {
		return NULL;
	}

	char *final = realloc(s, len + 1);
	if (!final) {
		return s;
	}

	final[len] = '\0';

	return final;
}

char *b_bstr_end(struct b_bstr *str)
{
	char *out = str->bstr_buf;
	size_t len = str->bstr_len;

	if (IS_DYNAMIC(str) && str->bstr_capacity - 1 > str->bstr_len) {
		/* bstr_buf is larger than required to contain the string.
		 * re-allocate it so it's only as large as necessary */
		out = truncate_buffer(out, len);
	}

	if (str->bstr_istack) {
		free(str->bstr_istack);
	}

	memset(str, 0x0, sizeof *str);

	return out;
}

enum b_status b_bstr_reserve(struct b_bstr *strv, size_t len)
{
	if (!IS_DYNAMIC(strv)) {
		return B_SUCCESS;
	}

	if (strv->bstr_capacity > 0 && strv->bstr_capacity - 1 >= len) {
		return B_SUCCESS;
	}

	char *new_buf = realloc(strv->bstr_buf, len + 1);
	if (!new_buf) {
		return B_ERR_NO_MEMORY;
	}

	strv->bstr_buf = new_buf;
	strv->bstr_capacity = len + 1;
	strv->bstr_buf[strv->bstr_len] = '\0';

	return B_SUCCESS;
}

static int current_indent(struct b_bstr *str)
{
	if (!str->bstr_istack || !str->bstr_istack_size) {
		return 0;
	}

	return str->bstr_istack[str->bstr_istack_ptr];
}

static void __formatter_putchar(struct b_bstr *str, char c)
{
	if (str->bstr_capacity > 0 && str->bstr_len < str->bstr_capacity - 1) {
		str->bstr_buf[str->bstr_len++] = c;
		str->bstr_buf[str->bstr_len] = '\0';
		return;
	}

	if (!CHECK_FLAG(str, B_BSTR_F_ALLOC)) {
		return;
	}

	size_t old_capacity = str->bstr_capacity;
	size_t new_capacity = old_capacity + CAPACITY_STEP;

	char *new_buf = realloc(str->bstr_buf, new_capacity);
	if (!new_buf) {
		return;
	}

	str->bstr_buf = new_buf;
	str->bstr_capacity = new_capacity;
	str->bstr_buf[str->bstr_len++] = c;
	str->bstr_buf[str->bstr_len] = '\0';
}

static void formatter_putchar(struct b_bstr *f, char c)
{
	if (f->bstr_add_indent && c != '\n') {
		int indent = current_indent(f);
		for (int i = 0; i < indent; i++) {
			__formatter_putchar(f, ' ');
			__formatter_putchar(f, ' ');
		}

		f->bstr_add_indent = 0;
	}

	__formatter_putchar(f, c);

	if (c == '\n') {
		f->bstr_add_indent = 1;
	}
}

static void bstr_fctprintf(char c, void *arg)
{
	struct b_bstr *str = arg;
	formatter_putchar(str, c);
}

static enum b_status bstr_putcs(
	struct b_bstr *str, const char *s, size_t len, size_t *nr_written)
{
	for (size_t i = 0; i < len; i++) {
		formatter_putchar(str, s[i]);
	}

	if (nr_written) {
		*nr_written = len;
	}

	return B_SUCCESS;
}

static enum b_status bstr_puts(struct b_bstr *str, const char *s, size_t *nr_written)
{
	size_t i;
	for (i = 0; s[i]; i++) {
		formatter_putchar(str, s[i]);
	}

	if (nr_written) {
		*nr_written = i;
	}

	return B_SUCCESS;
}

enum b_status b_bstr_push_indent(struct b_bstr *str, int indent)
{
	if (!str->bstr_istack) {
		str->bstr_istack = calloc(4, sizeof(int));
		str->bstr_istack_size = 4;
		str->bstr_istack_ptr = 0;
	}

	if (str->bstr_istack_ptr + 1 > str->bstr_istack_size) {
		int *buf = realloc(
			str->bstr_istack,
			(str->bstr_istack_size + 4) * sizeof(int));
		if (!buf) {
			return B_ERR_NO_MEMORY;
		}

		str->bstr_istack = buf;
		str->bstr_istack_size += 4;
	}

	int cur_indent = str->bstr_istack[str->bstr_istack_ptr];
	str->bstr_istack[++str->bstr_istack_ptr] = cur_indent + indent;

	return B_SUCCESS;
}

enum b_status b_bstr_pop_indent(struct b_bstr *strv)
{
	if (strv->bstr_istack_ptr > 0) {
		strv->bstr_istack_ptr--;
	}

	return B_SUCCESS;
}

enum b_status b_bstr_write_char(struct b_bstr *str, char c)
{
	formatter_putchar(str, c);
	return B_SUCCESS;
}

enum b_status b_bstr_write_chars(
	struct b_bstr *str, const char *s, size_t len, size_t *nr_written)
{
	return bstr_putcs(str, s, len, nr_written);
}

enum b_status b_bstr_write_cstr(struct b_bstr *str, const char *s, size_t *nr_written)
{
	return bstr_puts(str, s, nr_written);
}

enum b_status b_bstr_write_cstr_list(
	struct b_bstr *str, const char **strs, size_t *nr_written)
{
	size_t w = 0;
	enum b_status status = B_SUCCESS;

	for (size_t i = 0; strs[i]; i++) {
		size_t tmp = 0;
		status = bstr_puts(str, strs[i], &tmp);
		w += tmp;

		if (B_ERR(status)) {
			break;
		}
	}

	if (nr_written) {
		*nr_written = w;
	}

	return status;
}

enum b_status b_bstr_write_cstr_array(
	struct b_bstr *str, const char **strs, size_t count, size_t *nr_written)
{
	enum b_status status = B_SUCCESS;
	size_t w = 0;

	for (size_t i = 0; i < count; i++) {
		if (!strs[i]) {
			continue;
		}

		size_t tmp = 0;
		status = bstr_puts(str, strs[i], &tmp);
		w += tmp;

		if (B_ERR(status)) {
			break;
		}
	}

	if (nr_written) {
		*nr_written = w;
	}

	return status;
}

enum b_status b_bstr_add_many(struct b_bstr *str, size_t *nr_written, ...)
{
	va_list arg;
	va_start(arg, nr_written);
	const char *s = NULL;
	size_t w = 0;
	enum b_status status = B_SUCCESS;

	while ((s = va_arg(arg, const char *))) {
		size_t tmp = 0;
		status = bstr_puts(str, s, &tmp);
		w += tmp;

		if (B_ERR(status)) {
			break;
		}
	}

	if (nr_written) {
		*nr_written = w;
	}

	return status;
}

enum b_status b_bstr_write_rope(
	b_bstr *strv, const struct b_rope *rope, size_t *nr_written)
{
	size_t start = strv->bstr_len;
	enum b_status status = b_rope_to_bstr(rope, strv);
	size_t end = strv->bstr_len;

	if (nr_written) {
		*nr_written = end - start;
	}

	return status;
}

enum b_status b_bstr_write_fmt(
	struct b_bstr *str, size_t *nr_written, const char *format, ...)
{
	va_list arg;
	va_start(arg, format);
	enum b_status result = b_bstr_write_vfmt(str, nr_written, format, arg);
	va_end(arg);

	return result;
}

enum b_status b_bstr_write_vfmt(
	struct b_bstr *str, size_t *nr_written, const char *format, va_list arg)
{
	size_t start = str->bstr_len;
	z__b_fctprintf(bstr_fctprintf, str, format, arg);
	size_t end = str->bstr_len;

	if (nr_written) {
		*nr_written = end - start;
	}

	/* TODO update z__b_fctprintf to support propagating error codes */
	return B_SUCCESS;
}

char *b_bstr_rope(const struct b_rope *rope, size_t *nr_written)
{
	struct b_bstr str;
	b_bstr_begin_dynamic(&str);
	b_bstr_write_rope(&str, rope, nr_written);

	return b_bstr_end(&str);
}

char *b_bstr_fmt(size_t *nr_written, const char *format, ...)
{
	va_list arg;
	va_start(arg, format);
	char *s = b_bstr_vfmt(nr_written, format, arg);
	va_end(arg);
	return s;
}

char *b_bstr_vfmt(size_t *nr_written, const char *format, va_list arg)
{
	struct b_bstr str;
	b_bstr_begin_dynamic(&str);
	b_bstr_write_vfmt(&str, nr_written, format, arg);

	return b_bstr_end(&str);
}