import "../std/plugin.zc"

include <stdio.h>

fn bf_transpile(body: char*, api: ZApi*) {
    let out = api.out;
    
    fputs(f"""{{
    static unsigned char tape[30000] = {{0}};
    unsigned char *ptr = tape;
""", out);
    
    let idx = 0;
    while (body[idx] != 0) {
        let ch = body[idx];
        match ch {
            '>' => fputs("    ++ptr;\n", out),
            '<' => fputs("    --ptr;\n", out),
            '+' => fputs("    ++*ptr;\n", out),
            '-' => fputs("    --*ptr;\n", out),
            '.' => fputs("    putchar(*ptr);\n", out),
            ',' => fputs("    *ptr = getchar();\n", out),
            '[' => fputs(f"    while (*ptr) {{ \n", out),
            ']' => fputs(f"    }} \n", out),
            _ => (void)0
        }
        idx = idx + 1;
    }
    
    fputs(f"}} \n", out);
}

fn bf_hover(body: char*, line: int, col: int) -> char* {
    let p = body;
    let r = 0; let c = 0;
    // We don't skip newlines here to keep coordinate sync with ZLS
    while (p[0] != 0) {
        if (r == line && c == col) {
            match (int)p[0] {
                '>' => return "**:ptr++**: Increment the data pointer.",
                '<' => return "**:ptr--**: Decrement the data pointer.",
                '+' => return "**(*ptr)++**: Increment the byte at the data pointer.",
                '-' => return "**(*ptr)--**: Decrement the byte at the data pointer.",
                '.' => return "**:putchar**: Output the byte at the data pointer.",
                ',' => return "**:getchar**: Accept one byte of input, storing its value in the byte at the data pointer.",
                '[' => return "**:while(*ptr)**: If the byte at the data pointer is zero, jump forward to the command after the corresponding `]` command.",
                ']' => return "**:end-while**: If the byte at the data pointer is nonzero, jump back to the command after the corresponding `[` command.",
                _ => return NULL
            }
        }
        if (p[0] == 10) {
            r++; c = 0;
        } else {
            c++;
        }
        p = &p[1];
    }
    return NULL;
}

let bf_plugin = ZPlugin {
    name: "brainfuck",
    handler: bf_transpile,
    hover_handler: bf_hover
};

@export
fn z_plugin_init() -> ZPlugin* {
    return &bf_plugin;
}