#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>

#include <context.h>
#include <log.h>
#include <preprocess.h>
#include <tokenize.h>
#include <treeify.h>

struct ctx *context_create(const char *path)
{
	struct ctx *ctx = calloc(1, sizeof(*ctx));
	ctx->tokens = calloc(TOKENS_MAX, sizeof(*ctx->tokens));
	ctx->location.path = path; // TODO: strdup?

	FILE *file = fopen(path, "r");
	assert(file);

	// Find size of file
	fseek(file, 0, SEEK_END);
	ctx->location.size = ftell(file);
	rewind(file);
	assert(ctx->location.size);

	ctx->location.data = malloc(ctx->location.size + 1);
	assert(ctx->location.data);
	fread(ctx->location.data, 1, ctx->location.size, file);
	fclose(file);

	ctx->location.data[ctx->location.size] = 0;

	ctx->tree.head = tree_create();
	ctx->tree.current = NULL;

	return ctx;
}

void context_destroy(struct ctx *ctx)
{
	if (!ctx)
		return;

	if (ctx->location.data)
		free(ctx->location.data);

	if (ctx->data && ctx->data != ctx->location.data)
		free(ctx->data);

	if (ctx->tokens)
		free(ctx->tokens);

	if (ctx->tree.head)
		tree_destroy(ctx->tree.head);

	free(ctx);
}

char context_getch(struct ctx *ctx, size_t i)
{
	if (i >= ctx->size || !ctx->data[i])
		errln(&ctx->location, "Unexpected end of buffer");
	return ctx->data[i];
}

#define CONTEXT_COUNT 3
void context_print(FILE *fd, struct ctx_location *location)
{
	size_t start_line = fmax((int)location->line - CONTEXT_COUNT, 0);
	size_t end_line = location->line + CONTEXT_COUNT + 1;

	for (size_t line = 0, index = 0; line < end_line;) {
		if (line < start_line) {
			if (location->data[index] == '\n' || location->data[index] == MACRO_NEWLINE)
				line++;
			index++;
			continue;
		}

		const char *end = strchr(location->data + index, '\n') + 1;
		assert(end > location->data);
		size_t length = end - (location->data + index) - 1;

		if (location->line == line) {
			int pointer_length = location->column + 9;
			char *pointer = malloc(pointer_length); // Literally a pointer
			fprintf(fd,
				"\x1B[1;32m%6lu | %.*s\x1B[1;31m%c\x1B[1;32m%.*s\n\x1B[1;31m%.*s%s\x1B[0m\n",
				line + 1, (int)location->column, location->data + index,
				*(location->data + index + location->column),
				(int)(length - location->column - 1),
				location->data + index + location->column + 1, pointer_length,
				(char *)memset(pointer, '~', pointer_length), "^ (around here)");
			free(pointer);
		} else {
			fprintf(fd, "%6lu | %.*s\n", line + 1, (int)length, location->data + index);
		}

		index = end - location->data;
		line++;
		if (index >= location->size)
			return;
	}
}

void context_rewind(struct ctx *ctx)
{
	ctx->location.line = 0;
	ctx->location.column = 0;
}