module doc

import strings
import v.ast
import v.token

// merge_comments merges all the comment contents into a single text.
pub fn merge_comments(comments []ast.Comment) string {
	mut res := []string{}
	for comment in comments {
		res << comment.text.trim_left('\x01')
	}
	return res.join('\n')
}

// ast_comment_to_doc_comment converts an `ast.Comment` node type to a `DocComment`
pub fn ast_comment_to_doc_comment(ast_node ast.Comment) DocComment {
	text := ast_node.text // TODO .trim_left('\x01') // BUG why are this byte here in the first place?
	return DocComment{
		text: text
		is_multi: ast_node.is_multi
		pos: token.Pos{
			line_nr: ast_node.pos.line_nr
			col: 0 // ast_node.pos.pos - ast_node.text.len
			len: text.len
		}
	}
}

// ast_comments_to_doc_comments converts an array of `ast.Comment` nodes to
// an array of `DocComment` nodes
pub fn ast_comments_to_doc_comments(ast_nodes []ast.Comment) []DocComment {
	mut doc_comments := []DocComment{len: ast_nodes.len}
	for ast_comment in ast_nodes {
		doc_comments << ast_comment_to_doc_comment(ast_comment)
	}
	return doc_comments
}

// merge_doc_comments merges all the comments starting from
// the last up to the first item of the array.
pub fn merge_doc_comments(comments []DocComment) string {
	if comments.len == 0 {
		return ''
	}
	mut commentlines := []string{}
	mut last_comment_line_nr := 0
	for i := comments.len - 1; i >= 0; i-- {
		cmt := comments[i]
		if (!cmt.is_multi && last_comment_line_nr != 0
			&& cmt.pos.line_nr + 1 < last_comment_line_nr - 1) || (cmt.is_multi
			&& cmt.pos.line_nr + cmt.text.count('\n') + 1 < last_comment_line_nr - 1) {
			// skip comments that are not part of a continuous block,
			// located right above the top level statement.
			break
		}
		mut cmt_content := cmt.text.trim_left('\x01')
		if cmt.is_multi {
			// /**/ comments are deliberately NOT supported as vdoc comments,
			// so just ignore them:
			continue
		} else {
			if cmt_content.starts_with(' ') {
				cmt_content = cmt_content[1..]
			}
			commentlines << cmt_content
		}
		last_comment_line_nr = cmt.pos.line_nr + 1
	}
	commentlines = commentlines.reverse()
	mut is_codeblock := false
	mut previously_newline := true
	mut comment := ''
	for line in commentlines {
		if line.starts_with('```') {
			is_codeblock = !is_codeblock
			comment = comment + '\n' + line
			continue
		} else if is_codeblock {
			comment = comment + '\n' + line
			continue
		}

		line_trimmed := line.trim(' ')

		mut is_horizontalrule := false
		line_no_spaces := line_trimmed.replace(' ', '')
		for ch in ['-', '=', '*', '_', '~'] {
			if line_no_spaces.starts_with(ch.repeat(3))
				&& line_no_spaces.count(ch) == line_no_spaces.len {
				is_horizontalrule = true
				break
			}
		}

		if line_trimmed == '' || is_horizontalrule
			|| (line.starts_with('#') && line.before(' ').count('#') == line.before(' ').len)
			|| (line_trimmed.starts_with('|') && line_trimmed.ends_with('|'))
			|| line_trimmed.starts_with('- ') {
			comment = comment + '\n' + line
			previously_newline = true
		} else if line.ends_with('.') {
			comment = comment + '\n' + line + '  '
			previously_newline = true
		} else {
			sep := if previously_newline { '\n' } else { ' ' }
			comment = comment + sep + line
			previously_newline = false
		}
	}
	return comment
}

// stmt_signature returns the signature of a given `ast.Stmt` node.
pub fn (mut d Doc) stmt_signature(stmt ast.Stmt) string {
	match stmt {
		ast.Module {
			return 'module $stmt.name'
		}
		ast.FnDecl {
			return stmt.stringify(d.table, d.fmt.cur_mod, d.fmt.mod2alias)
		}
		else {
			d.fmt.out = strings.new_builder(1000)
			d.fmt.stmt(stmt)
			return d.fmt.out.str().trim_space()
		}
	}
}

// stmt_name returns the name of a given `ast.Stmt` node.
pub fn (d Doc) stmt_name(stmt ast.Stmt) string {
	match stmt {
		ast.FnDecl, ast.StructDecl, ast.EnumDecl, ast.InterfaceDecl {
			return stmt.name
		}
		ast.TypeDecl {
			match stmt {
				ast.FnTypeDecl, ast.AliasTypeDecl, ast.SumTypeDecl { return stmt.name }
			}
		}
		ast.ConstDecl {
			return ''
		} // leave it blank
		else {
			return ''
		}
	}
}

// stmt_pub returns a boolean if a given `ast.Stmt` node
// is exposed to the public.
pub fn (d Doc) stmt_pub(stmt ast.Stmt) bool {
	match stmt {
		ast.FnDecl, ast.StructDecl, ast.EnumDecl, ast.InterfaceDecl, ast.ConstDecl {
			return stmt.is_pub
		}
		ast.TypeDecl {
			match stmt {
				ast.FnTypeDecl, ast.AliasTypeDecl, ast.SumTypeDecl { return stmt.is_pub }
			}
		}
		else {
			return false
		}
	}
}

// type_to_str is a wrapper function around `fmt.ast.type_to_str`.
pub fn (mut d Doc) type_to_str(typ ast.Type) string {
	// why is it the default behaviour of ast.type_to_str
	// to convert math.bits.Type to bits.Type?
	d.table.cmod_prefix = d.orig_mod_name + '.'
	return d.fmt.table.type_to_str(typ).all_after('&')
}

// expr_typ_to_string has the same function as `Doc.typ_to_str`
// but for `ast.Expr` nodes. The checker will check first the
// node and it executes the `type_to_str` method.
pub fn (mut d Doc) expr_typ_to_string(ex ast.Expr) string {
	expr_typ := d.checker.expr(ex)
	return d.type_to_str(expr_typ)
}