/**************************************************************/
/*  treebnf: a tree oriented bnf library                      */
/*  Copyright (C) 2024  SysDeer Technologies, LLC             */
/*  Released under GPLv2 and GPLv3; see COPYING.TREEBNF.      */
/**************************************************************/

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <treebnf/treebnf.h>

#include "treebnf_driver_impl.h"
#include "treebnf_dprintf_impl.h"

static const char aclr_reset[]   = "\x1b[0m";
static const char aclr_bold[]    = "\x1b[1m";

static const char aclr_green[]   = "\x1b[32m";
static const char aclr_blue[]    = "\x1b[34m";
static const char aclr_magenta[] = "\x1b[35m";

static const char * tbnf_output_error_header(const struct tbnf_error_info * erri)
{
	if (erri->eflags & TBNF_ERROR_CHILD)
		return "exec error upon";

	else if (erri->eflags & TBNF_ERROR_TOP_LEVEL)
		return "error logged in";

	else if (erri->eflags & TBNF_ERROR_NESTED)
		return "< returned to >";

	else
		return "distorted state";
}

static const char * tbnf_output_strerror(
	const struct tbnf_error_info * erri,
	char (*errbuf)[256])
{
	if (erri->eflags & TBNF_ERROR_CUSTOM)
		return "flow error: unexpected condition or other";

	else if (erri->eflags & TBNF_ERROR_NESTED)
		return "";

	else if (erri->eflags & TBNF_ERROR_CHILD)
		return "(see child process error messages)";

	else if (erri->esyscode == ENOBUFS)
		return "input error: string length exceeds buffer size";

	else if ((erri->esyscode == ENOENT) && erri->eany)
		return "path not found: ";

	else
		return strerror_r(erri->esyscode,*errbuf,sizeof(*errbuf))
			? "internal error: strerror_r(3) call failed"
			: *errbuf;
}

static int tbnf_output_error_record_plain(
	const struct tbnf_driver_ctx *	dctx,
	const struct tbnf_error_info *	erri)
{
	char         errbuf[256];

	int          fderr   = tbnf_driver_fderr(dctx);
	const char * errdesc = tbnf_output_strerror(erri,&errbuf);
	const char * path;

	path = ((erri->esyscode == ENOENT) && erri->eany)
		? erri->eany : "";

	if (tbnf_dprintf(
			fderr,
			"%s: %s %s(), line %d%s%s%s.\n",
			dctx->program,
			tbnf_output_error_header(erri),
			erri->efunction,
			erri->eline,
			strlen(errdesc) ? ": " : "",
			errdesc,path) < 0)
		return -1;

	return 0;
}

static int tbnf_output_error_record_annotated(
	const struct tbnf_driver_ctx *	dctx,
	const struct tbnf_error_info *	erri)
{
	char         errbuf[256];

	int          fderr   = tbnf_driver_fderr(dctx);
	const char * errdesc = tbnf_output_strerror(erri,&errbuf);
	const char * path;

	path = ((erri->esyscode == ENOENT) && erri->eany)
		? erri->eany : "";

	if (tbnf_dprintf(
			fderr,
			"%s%s%s:%s %s%s%s %s%s%s()%s, %s%sline %d%s%s%s%s%s%s%s%s%s.\n",

			aclr_bold,aclr_magenta,
			dctx->program,
			aclr_reset,

			aclr_bold,
			tbnf_output_error_header(erri),
			aclr_reset,

			aclr_bold,aclr_blue,
			erri->efunction,
			aclr_reset,

			aclr_bold,aclr_green,
			erri->eline,
			aclr_reset,
			strlen(errdesc) ? ": " : "",

			aclr_bold,
			errdesc,
			aclr_reset,

			aclr_bold,aclr_blue,
			path,
			aclr_reset) < 0)
		return -1;

	return 0;
}

int tbnf_output_error_record(
	const struct tbnf_driver_ctx *	dctx,
	const struct tbnf_error_info *	erri)
{
	int fderr = tbnf_driver_fderr(dctx);

	if (dctx->cctx->drvflags & TBNF_DRIVER_ANNOTATE_NEVER)
		return tbnf_output_error_record_plain(dctx,erri);

	else if (dctx->cctx->drvflags & TBNF_DRIVER_ANNOTATE_ALWAYS)
		return tbnf_output_error_record_annotated(dctx,erri);

	else if (isatty(fderr))
		return tbnf_output_error_record_annotated(dctx,erri);

	else
		return tbnf_output_error_record_plain(dctx,erri);
}

static int tbnf_output_error_vector_plain(const struct tbnf_driver_ctx * dctx)
{
	struct tbnf_error_info ** perr;

	for (perr=dctx->errv; *perr; perr++)
		if (tbnf_output_error_record_plain(dctx,*perr))
			return -1;

	return 0;
}

static int tbnf_output_error_vector_annotated(const struct tbnf_driver_ctx * dctx)
{
	struct tbnf_error_info ** perr;

	for (perr=dctx->errv; *perr; perr++)
		if (tbnf_output_error_record_annotated(dctx,*perr))
			return -1;

	return 0;
}

int tbnf_output_error_vector(const struct tbnf_driver_ctx * dctx)
{
	int fderr = tbnf_driver_fderr(dctx);

	if (dctx->cctx->drvflags & TBNF_DRIVER_ANNOTATE_NEVER)
		return tbnf_output_error_vector_plain(dctx);

	else if (dctx->cctx->drvflags & TBNF_DRIVER_ANNOTATE_ALWAYS)
		return tbnf_output_error_vector_annotated(dctx);

	else if (isatty(fderr))
		return tbnf_output_error_vector_annotated(dctx);

	else
		return tbnf_output_error_vector_plain(dctx);
}