#ifndef MD_LINE_INDEX_H
#define MD_LINE_INDEX_H

#include <stddef.h>
#include <stdint.h>

#define SASHIDOWN_MAX_LINE_INDEX 16384

typedef struct {
    uint32_t *off;   /* line-start offsets; off[n] is end sentinel */
    uint32_t  n;     /* number of line starts (off[0]..off[n-1]) */
    uint32_t  cur;   /* sequential cursor: line index for last lookup */
    uint32_t  cap;   /* slots in off[] (must be >= n+1 when valid) */
    int       valid; /* 0 if doc exceeded index capacity / OOM */
    int       owned; /* 1 if off was malloc'd (stream path) */
} line_index_t;

/* Stack-backed index for zero-malloc parse/convert hot path. */
#define LINE_INDEX_STACK(name)                                                 \
    uint32_t name##_off_[SASHIDOWN_MAX_LINE_INDEX + 1];                           \
    line_index_t name = {                                                      \
        .off = name##_off_, .n = 0, .cur = 0,                                  \
        .cap = SASHIDOWN_MAX_LINE_INDEX + 1, .valid = 1, .owned = 0               \
    }

int  line_index_init_dynamic(line_index_t *ix, uint32_t initial_cap);
void line_index_free(line_index_t *ix);

void line_index_build(const char *input, size_t len, line_index_t *ix);

/* Extend for input[old_len..new_len). Returns absolute offset after the last
 * newline in that range, or 0 if none. */
size_t line_index_extend(line_index_t *ix, const char *input,
                         size_t old_len, size_t new_len);

void line_index_seek(line_index_t *ix, size_t pos);
size_t line_end_ix(line_index_t *ix, const char *input, size_t len, size_t pos);
size_t skip_line_ix(line_index_t *ix, const char *input, size_t len, size_t pos);

#endif /* MD_LINE_INDEX_H */