#ifndef SASHIDOWN_H
#define SASHIDOWN_H

#include <stddef.h>

#define SASHIDOWN_OUTPUT_DEFAULT 65536

typedef struct {
    const char *input;
    size_t       input_len;
    char        *output;
    size_t       output_cap;
    size_t       output_len;
    char        *write_ptr;
    char        *write_end;
    void        *line_ix;
    int          overflow; /* set when output buffer is exhausted */
} sashidown_ctx_t;

/* Parse markdown to HTML. Returns 0 on success, -1 on error
 * (null args, or output buffer too small — never silently truncates). */
int sashidown_parse(const char *input, size_t len,
                 char *output, size_t cap, size_t *out_len);

typedef enum {
    SASHIDOWN_FMT_HTML = 0,
    SASHIDOWN_FMT_ANSI = 1,       /* built-in colorful terminal theme */
    SASHIDOWN_FMT_JSON = 2,
    SASHIDOWN_FMT_ANSI_PLAIN = 3, /* monochrome / SGR attributes only */
} sashidown_format_t;

/* Single-pass convert. SASHIDOWN_FMT_HTML delegates to sashidown_parse.
 * Returns 0 on success, -1 on error (null args, bad format, or buffer too small). */
int sashidown_convert(const char *input, size_t len,
                   char *output, size_t cap, size_t *out_len,
                   sashidown_format_t format);

/* Allocating wrapper (thread-safe). Caller must free via sashidown_free. */
char *cmark_markdown_to_html(const char *text, int len);
void  sashidown_free(void *ptr);

/* --- Streaming API (AI conversation / incremental input) --- */

typedef struct sashidown_stream sashidown_stream_t;

/* Called for each HTML chunk; return non-zero to abort feeding. */
typedef int (*sashidown_stream_cb)(const char *html, size_t len, void *user);

typedef struct {
    sashidown_stream_cb on_html;
    void            *user;
    size_t           output_buf_size; /* default 8192 if 0; grows on overflow */
} sashidown_stream_opts_t;

sashidown_stream_t *sashidown_stream_create(const sashidown_stream_opts_t *opts);
int sashidown_stream_feed(sashidown_stream_t *s, const char *chunk, size_t len);
int sashidown_stream_finish(sashidown_stream_t *s);
void sashidown_stream_destroy(sashidown_stream_t *s);

/* Bytes held past the confirmation frontier (input_len - render_pos).
 * Unconfirmed suffix under uncertain future input; O(1) query. */
size_t sashidown_stream_pending(const sashidown_stream_t *s);

#endif /* SASHIDOWN_H */