#ifndef HTTP_H
#define HTTP_H

struct packed_git;
struct packfile_list;

#include "git-zlib.h"

#include <curl/curl.h>
#include <curl/easy.h>

#include "gettext.h"
#include "strbuf.h"
#include "remote.h"

#define DEFAULT_MAX_REQUESTS 5

struct slot_results {
	CURLcode curl_result;
	long http_code;
	long auth_avail;
	long http_connectcode;
	long retry_after;
};

struct active_request_slot {
	CURL *curl;
	int in_use;
	CURLcode curl_result;
	long http_code;
	int *finished;
	struct slot_results *results;
	void *callback_data;
	void (*callback_func)(void *data);
	struct active_request_slot *next;
};

struct buffer {
	struct strbuf buf;
	size_t posn;
};

/* Curl request read/write callbacks */
size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
int seek_buffer(void *clientp, curl_off_t offset, int origin);

/* Slot lifecycle functions */
struct active_request_slot *get_active_slot(void);
int start_active_slot(struct active_request_slot *slot);
void run_active_slot(struct active_request_slot *slot);
void finish_all_active_slots(void);

/*
 * This will run one slot to completion in a blocking manner, similar to how
 * curl_easy_perform would work (but we don't want to use that, because
 * we do not want to intermingle calls to curl_multi and curl_easy).
 *
 */
int run_one_slot(struct active_request_slot *slot,
		 struct slot_results *results);

void fill_active_slots(void);
void add_fill_function(void *data, int (*fill)(void *));
void step_active_slots(void);

void http_init(struct remote *remote, const char *url,
	       int proactive_auth);
void http_cleanup(void);
struct curl_slist *http_copy_default_headers(void);

extern long int git_curl_ipresolve;
extern int active_requests;
extern int http_is_verbose;
extern ssize_t http_post_buffer;
extern struct credential http_auth;

extern char curl_errorstr[CURL_ERROR_SIZE];

enum http_follow_config {
	HTTP_FOLLOW_NONE,
	HTTP_FOLLOW_ALWAYS,
	HTTP_FOLLOW_INITIAL
};
extern enum http_follow_config http_follow_config;

static inline int missing__target(int code, int result)
{
	return	/* file:// URL -- do we ever use one??? */
		(result == CURLE_FILE_COULDNT_READ_FILE) ||
		/* http:// and https:// URL */
		(code == 404 && result == CURLE_HTTP_RETURNED_ERROR) ||
		/* ftp:// URL */
		(code == 550 && result == CURLE_FTP_COULDNT_RETR_FILE)
		;
}

#define missing_target(a) missing__target((a)->http_code, (a)->curl_result)

static inline curl_off_t cast_size_t_to_curl_off_t(size_t a)
{
	uintmax_t size = a;
	if (size > maximum_signed_value_of_type(curl_off_t))
		die(_("number too large to represent as curl_off_t "
		      "on this platform: %"PRIuMAX), (uintmax_t)a);
	return (curl_off_t)a;
}

/*
 * Normalize curl results to handle CURL_FAILONERROR (or lack thereof). Failing
 * http codes have their "result" converted to CURLE_HTTP_RETURNED_ERROR, and
 * an appropriate string placed in the errorstr buffer (pass curl_errorstr if
 * you don't have a custom buffer).
 */
void normalize_curl_result(CURLcode *result, long http_code, char *errorstr,
			   size_t errorlen);

/* Helpers for modifying and creating URLs */
void append_remote_object_url(struct strbuf *buf, const char *url,
			      const char *hex,
			      int only_two_digit_prefix);
char *get_remote_object_url(const char *url, const char *hex,
			    int only_two_digit_prefix);

/* Options for http_get_*() */
struct http_get_options {
	unsigned no_cache:1,
		 initial_request:1;

	/* If non-NULL, returns the content-type of the response. */
	struct strbuf *content_type;

	/*
	 * If non-NULL, and content_type above is non-NULL, returns
	 * the charset parameter from the content-type. If none is
	 * present, returns an empty string.
	 */
	struct strbuf *charset;

	/*
	 * If non-NULL, returns the URL we ended up at, including any
	 * redirects we followed.
	 */
	struct strbuf *effective_url;

	/*
	 * If both base_url and effective_url are non-NULL, the base URL will
	 * be munged to reflect any redirections going from the requested url
	 * to effective_url. See the definition of update_url_from_redirect
	 * for details.
	 */
	struct strbuf *base_url;

	/*
	 * If not NULL, contains additional HTTP headers to be sent with the
	 * request. The strings in the list must not be freed until after the
	 * request has completed.
	 */
	struct string_list *extra_headers;

	/*
	 * After a request completes, contains the Retry-After delay in seconds
	 * if the server returned HTTP 429 with a Retry-After header (requires
	 * libcurl 7.66.0 or later), or -1 if no such header was present.
	 */
	long retry_after;
};

/* Return values for http_get_*() */
#define HTTP_OK			0
#define HTTP_MISSING_TARGET	1
#define HTTP_ERROR		2
#define HTTP_START_FAILED	3
#define HTTP_REAUTH	4
#define HTTP_NOAUTH	5
#define HTTP_NOMATCHPUBLICKEY	6
#define HTTP_RATE_LIMITED	7

/*
 * Requests a URL and stores the result in a strbuf.
 *
 * If the result pointer is NULL, a HTTP HEAD request is made instead of GET.
 */
int http_get_strbuf(const char *url, struct strbuf *result, struct http_get_options *options);

/*
 * Downloads a URL and stores the result in the given file.
 *
 * If a previous interrupted download is detected (i.e. a previous temporary
 * file is still around) the download is resumed.
 */
int http_get_file(const char *url, const char *filename,
		  struct http_get_options *options);

int http_fetch_ref(const char *base, struct ref *ref);

struct curl_slist *http_append_auth_header(const struct credential *c,
					   struct curl_slist *headers);

/* Helpers for fetching packs */
int http_get_info_packs(const char *base_url,
			struct packfile_list *packs);

/* Helper for getting Accept-Language header */
const char *http_get_accept_language_header(void);

struct http_pack_request {
	char *url;

	/*
	 * index-pack command to run. Must be terminated by NULL.
	 *
	 * If NULL, defaults to	{"index-pack", "--stdin", NULL}.
	 */
	const char **index_pack_args;
	unsigned preserve_index_pack_stdout : 1;

	FILE *packfile;
	struct strbuf tmpfile;
	struct active_request_slot *slot;
	struct curl_slist *headers;
};

struct http_pack_request *new_http_pack_request(
	const unsigned char *packed_git_hash, const char *base_url);
struct http_pack_request *new_direct_http_pack_request(
	const unsigned char *packed_git_hash, char *url);
int finish_http_pack_request(struct http_pack_request *preq);
void release_http_pack_request(struct http_pack_request *preq);

/*
 * Remove p from the given list, and invoke packfile_store_add_pack() on it.
 *
 * This is a convenience function for users that have obtained a list of packs
 * from http_get_info_packs() and have chosen a specific pack to fetch.
 */
void http_install_packfile(struct packed_git *p,
			   struct packfile_list *list_to_remove_from);

/* Helpers for fetching object */
struct http_object_request {
	char *url;
	struct strbuf tmpfile;
	int localfile;
	CURLcode curl_result;
	char errorstr[CURL_ERROR_SIZE];
	long http_code;
	struct object_id oid;
	struct object_id real_oid;
	struct git_hash_ctx c;
	git_zstream stream;
	int zret;
	int rename;
	struct active_request_slot *slot;
	struct curl_slist *headers;
};

struct http_object_request *new_http_object_request(
	const char *base_url, const struct object_id *oid);
void process_http_object_request(struct http_object_request *freq);
int finish_http_object_request(struct http_object_request *freq);
void abort_http_object_request(struct http_object_request **freq);
void release_http_object_request(struct http_object_request **freq);

/*
 * Instead of using environment variables to determine if curl tracing happens,
 * behave as if GIT_TRACE_CURL=1 and GIT_TRACE_CURL_NO_DATA=1 is set. Call this
 * before calling setup_curl_trace().
 */
void http_trace_curl_no_data(void);

/* setup routine for curl_easy_setopt CURLOPT_DEBUGFUNCTION */
void setup_curl_trace(CURL *handle);
#endif /* HTTP_H */