parser.js

var h = require("./helpers");

var parser = {};

var regex = {
    title_page: /(title|credit|author[s]?|source|notes|draft date|date|contact|copyright)\:.*/i,

    section: /^(#+)(?: *)(.*)/,
    synopsis: /^(?:\=(?!\=+) *)(.*)/,

    scene_heading: /^((?:\*{0,3}_?)?(?:(?:int|ext|est|int\/ext|i\.?\/e\.?)[. ]).+)|^(?:\.(?!\.+))(.+)/i,
    scene_number: /#(.+)#/,

    transition: /^((?:FADE (?:TO BLACK|OUT)|CUT TO BLACK)\.|.+ TO\:|^TO\:$)|^(?:> *)(.+)/,

    dialogue: /^([A-Z*_]+[0-9A-Z (._\-')]*)(\^?)?(?:\n(?!\n+))([\s\S]+)/,
    character: /^([A-Z*_]+[0-9A-Z (._\-')]*)\^?$|^@.*$/,
    parenthetical: /^(\(.+\))$/,

    action: /^(.+)/g,
    centered: /^(?:> *)(.+)(?: *<)(\n.+)*/g,

    page_break: /^\={3,}$/,
    line_break: /^ {2}$/
};

parser.parse = function(original_script, cfg) {

    var script = original_script,
        result = {
            title_page: [],
            tokens: []
        };
    if (!script) {
        return result;
    }

    var new_line_length = script.match(/\r\n/) ? 2 : 1;

    if (!cfg.print_notes) {
        script = script.replace(/ {0,1}\[\[/g, " /*").replace(/\]\] {0,1}/g, "*/");
    }

    var lines = script.split(/\r\n|\r|\n/);

    var create_token = function(text, cursor, line) {
        return h.create_token({
            text: text,
            start: cursor,
            end: cursor + text.length - 1 + new_line_length,
            line: line
        });
    };

    var lines_length = lines.length,
        current = 0,
        scene_number = 1,
        match, text, last_title_page_token,
        token, last_was_separator = false,
        top_or_separated = false,
        token_category = "none",
        last_character_index,
        dual_right,
        state = "normal",
        cache_state_for_comment,
        nested_comments = 0,
        title_page_started = false;


    var reduce_comment = function(prev, current) {
        if (current === "/*") {
            nested_comments++;
        } else if (current === "*/") {
            nested_comments--;
        } else if (!nested_comments) {
            prev = prev + current;
        }
        return prev;
    };

    var if_not_empty = function(a) {
        return a;
    };

    for (var i = 0; i < lines_length; i++) {
        text = lines[i];

        // replace inline comments
        text = text.split(/(\/\*){1}|(\*\/){1}|([^\/\*]+)/g).filter(if_not_empty).reduce(reduce_comment, "");

        if (nested_comments && state !== "ignore") {
            cache_state_for_comment = state;
            state = "ignore";
        } else if (state === "ignore") {
            state = cache_state_for_comment;
        }

        if (nested_comments === 0 && state === "ignore") {
            state = cache_state_for_comment;
        }


        token = create_token(text, current, i);
        current = token.end + 1;

 
        if (text.trim().length === 0 && text !== "  ") {
            var skip_separator = cfg.merge_multiple_empty_lines && last_was_separator;

            state = "normal";

            if (skip_separator || state === "title_page") {
                continue;
            }

            dual_right = false;
            token.type = "separator";
            last_was_separator = true;
            result.tokens.push(token);
            continue;
        }

        top_or_separated = last_was_separator || i === 0;
        token_category = "script";

        if (!title_page_started && regex.title_page.test(token.text)) {
            state = "title_page";
        }

        if (state === "title_page") {
            if (regex.title_page.test(token.text)) {
                var index = token.text.indexOf(":");
                token.type = token.text.substr(0, index).toLowerCase();
                token.text = token.text.substr(index + 1).trim();
                last_title_page_token = token;
                result.title_page.push(token);
                title_page_started = true;
                continue;
            } else if (title_page_started) {
                last_title_page_token.text += (last_title_page_token.text ? "\n" : "") + token.text.trim();
                continue;
            }
        }

        if (state === "normal") {
            if (token.text.match(regex.line_break)) {
                token_category = "none";
            } else if (token.text.match(regex.scene_heading)) {
                token.text = token.text.replace(/^\./, "");
                if (cfg.each_scene_on_new_page && scene_number !== 1) {
                    var page_break = h.create_token({
                        type: "page_break",
                        start: token.start,
                        end: token.end
                    });
                    result.tokens.push(page_break);
                }

                token.type = "scene_heading";
                token.number = scene_number;
                if (match = token.text.match(regex.scene_number)) {
                    token.text = token.text.replace(regex.scene_number, "");
                    token.number = match[1];
                }
                scene_number++;
            } else if (token.text.match(regex.centered)) {
                token.type = "centered";
                token.text = token.text.replace(/>|</g, "").trim();
            } else if (token.text.match(regex.transition)) {
                token.text = token.text.replace(/> ?/, "");
                token.type = "transition";
            } else if (match = token.text.match(regex.synopsis)) {
                token.text = match[1];
                token.type = token.text ? "synopsis" : "separator";
            } else if (match = token.text.match(regex.section)) {
                token.level = match[1].length;
                token.text = match[2];
                token.type = "section";
            } else if (token.text.match(regex.page_break)) {
                token.text = "";
                token.type = "page_break";
            } else if (token.text.length && token.text[0] === "!") {
                token.type = "action";
                token.text = token.text.substr(1);
            } else if ((token.text.length > 0 && token.text[0] === "@") || (token.text === token.text.toUpperCase() && top_or_separated)) {
                if (i === lines_length || i === lines_length - 1 || lines[i + 1].trim().length === 0) {
                    token.type = "shot";
                } else {
                    state = "dialogue";
                    token.type = "character";
                    token.text = token.text.replace(/^@/, "");
                    if (token.text[token.text.length - 1] === "^") {
                        if (cfg.use_dual_dialogue) {
                            // update last dialogue to be dual:left
                            var dialogue_tokens = ["dialogue", "character", "parenthetical"];
                            while (dialogue_tokens.indexOf(result.tokens[last_character_index].type) !== -1) {
                                result.tokens[last_character_index].dual = "left";
                                last_character_index++;
                            }
                            token.dual = "right";
                            dual_right = true;
                        }
                        token.text = token.text.replace("^", "");
                    } else if (last_character_index !== undefined && result.tokens[last_character_index].text === token.text && cfg.dialogue_contd) {
                        token.text = token.text.trim() + ' ' + cfg.dialogue_contd;
                    }
                    last_character_index = result.tokens.length;
                }
            }
            else {
                token.type = "action";
            }
        } else {
            if (token.text.match(regex.parenthetical)) {
                token.type = "parenthetical";
            } else {
                token.type = "dialogue";
            }
            if (dual_right) {
                token.dual = "right";
            }
        }

        last_was_separator = false;

        if (token_category === "script" && state !== "ignore") {
            if (token.is("scene_heading", "transition")) {
                token.text = token.text.toUpperCase();
                title_page_started = true; // ignore title tags after first heading
            }
            if (token.text && token.text[0] === "~") {
                token.text = "*" + token.text.substr(1) + "*";
            }
            token.text = token.is("action") ? token.text : token.text.trim();
            result.tokens.push(token);
        }

    }

    var current_index = 0, previous_type = null;
    // tidy up separators
    while (current_index < result.tokens.length) {
        var current_token = result.tokens[current_index];

        if (
            (!cfg.print_actions && current_token.is("action", "transition", "centered", "shot")) ||
            (!cfg.print_notes && current_token.type === "note") ||
            (!cfg.print_headers && current_token.type === "scene_heading") ||
            (!cfg.print_sections && current_token.type === "section") ||
            (!cfg.print_synopsis && current_token.type === "synopsis") ||
            (!cfg.print_dialogues && current_token.is_dialogue()) ||
            (cfg.merge_multiple_empty_lines && current_token.is("separator") && previous_type === "separator")) {

            result.tokens.splice(current_index, 1);
            continue;
        }

        if (cfg.double_space_between_scenes && current_token.is("scene_heading") && current_token.number !== 1) {
            var additional_separator = h.create_separator(token.start, token.end);
            result.tokens.splice(current_index, 0, additional_separator);
            current_index++;
        }
        previous_type = current_token.type;
        current_index++;
    }

    // clean separators at the end
    while (result.tokens.length > 0 && result.tokens[result.tokens.length - 1].type === "separator") {
        result.tokens.pop();
    }

    return result;
};

module.exports = parser;