package main

// TODO: read a file line by line

import (
	"fmt"
	"log"
	"os"
	"strings"
)

type heading struct {
	text  string
	level int
	line  int
}

func is_heading(line string) bool {
	if strings.HasPrefix(line, "#") {
		return true
	} else {
		return false
	}
}

func get_heading_level(heading_text string) int {
	level := 0
	for i := 0; heading_text[i] == '#'; i++ {
		level += 1
	}
	return level
}

func count_levels(headings []heading) map[int]int {
	level_count := make(map[int]int)

	for index, _ := range headings {
		switch headings[index].level {
		case 1:
			level_count[1]++
		case 2:
			level_count[2]++
		case 3:
			level_count[3]++
		case 4:
			level_count[4]++
		case 5:
			level_count[5]++
		case 6:
			level_count[6]++
		}
	}

	return level_count
}

func main() {
	file_content_raw, err := os.ReadFile(os.Args[1])

	var headings []heading = nil

	if err != nil {
		log.Fatal(err)
	}

	var file_content string = string(file_content_raw)

	file_lines := strings.Split(file_content, "\n")

	for index, value := range file_lines {
		if is_heading(value) {
			headings = append(
				headings, heading{value, get_heading_level(value), (index + 1)})
		}
	}

	fmt.Printf("%v\n", headings)

	header_level_count := count_levels(headings)

	for i := 0; i <= 6; i++ {
		if header_level_count[i] != 0 {
			fmt.Printf("Header %d occurs %d times.\n", i, header_level_count[i])
		}
	}
}