var fs = require('fs'),
    path = require('path'),
    glob = require('glob'),
    YAML = require('js-yaml'),
    _ = require('./js/lib/lodash'),
    jsonschema = require('jsonschema'),
    fieldSchema = require('./data/presets/schema/field.json'),
    presetSchema = require('./data/presets/schema/preset.json'),
    suggestions = require('./data/name-suggestions.json');

function readtxt(f) {
    return fs.readFileSync(f, 'utf8');
}

function read(f) {
    return JSON.parse(readtxt(f));
}

function r(f) {
    return read(__dirname + '/data/' + f);
}

function rp(f) {
    return r('presets/' + f);
}

function stringify(o) {
    return JSON.stringify(o, null, 4);
}

function validate(file, instance, schema) {
    var result = jsonschema.validate(instance, schema);
    if (result.length) {
        console.error(file + ": ");
        result.forEach(function(error) {
            if (error.property) {
                console.error(error.property + ' ' + error.message);
            } else {
                console.error(error);
            }
        });
        process.exit(1);
    }
}

var translations = {
    categories: {},
    fields: {},
    presets: {}
};

function generateCategories() {
    var categories = {};
    glob.sync(__dirname + '/data/presets/categories/*.json').forEach(function(file) {
        var field = read(file),
            id = 'category-' + path.basename(file, '.json');

        translations.categories[id] = {name: field.name};

        categories[id] = field;
    });
    return categories;
}

function generateFields() {
    var fields = {};
    glob.sync(__dirname + '/data/presets/fields/**/*.json').forEach(function(file) {
        var field = read(file),
            id = file.match(/presets\/fields\/([^.]*)\.json/)[1];

        validate(file, field, fieldSchema);

        var t = translations.fields[id] = {
            label: field.label
        };

        if (field.placeholder) {
            t.placeholder = field.placeholder;
        }

        if (field.strings) {
            for (var i in field.strings) {
                t[i] = field.strings[i];
            }
        }

        fields[id] = field;
    });
    return fields;
}

function suggestionsToPresets(presets) {
    var existing = {},
        countThreshold = 0;

    for (var preset in presets) {
        existing[presets[preset].name] = {
            category: preset,
            count: -1
        };
    }

    for (var key in suggestions) {
        for (var value in suggestions[key]) {
            for (var name in suggestions[key][value]) {
                var item = key + '/' + value + '/' + name,
                    tags = {},
                    count = suggestions[key][value][name].count;

                tags = _.extend({name: name}, suggestions[key][value][name].tags);

                if (!existing[name] && count > countThreshold) addPreset(item, tags, name, count);
            }
        }
    }

    function addPreset(category, tags, name, count) {
        var tag = category.split('/'),
            parent = presets[tag[0] + '/' + tag[1]];

        presets[category] = {
            tags: parent.tags ? _.merge(tags, parent.tags) : tags,
            name: name,
            icon: parent.icon,
            geometry: parent.geometry,
            fields: parent.fields,
            suggestion: true
        };

        existing[name] = {
            category: category,
            count: count
        };
    }

    return presets;
}

function generatePresets() {
    var presets = {};

    // A closed way is considered to be an area if it has a tag with one
    // of the following keys, and the value is _not_ one of the associated
    // values for the respective key.
    var areaKeys = {};

    glob.sync(__dirname + '/data/presets/presets/**/*.json').forEach(function(file) {
        var preset = read(file),
            id = file.match(/presets\/presets\/([^.]*)\.json/)[1];

        validate(file, preset, presetSchema);

        translations.presets[id] = {
            name: preset.name,
            terms: (preset.terms || []).join(',')
        };

        for (var key in preset.tags) break;
        var value = preset.tags[key];

        if (['highway', 'footway', 'railway', 'type'].indexOf(key) === -1) {
            if (preset.geometry.indexOf('area') >= 0) {
                areaKeys[key] = areaKeys[key] || {};
            } else if (key in areaKeys && value !== '*') {
                areaKeys[key][value] = true;
            }
        }

        presets[id] = preset;
    });

    presets = _.merge(presets, suggestionsToPresets(presets));

    var presetsYaml = _.cloneDeep(translations);
    _.forEach(presetsYaml.presets, function(preset) {
        preset.terms = "<translate with synonyms or related terms for '" + preset.name + "', separated by commas>"
    });

    return {
        presets: presets,
        areaKeys: areaKeys,
        presetsYaml: presetsYaml
    };
}

function validateCategoryPresets(categories, presets) {
    _.forEach(categories, function(category) {
        if (category.members) {
            category.members.forEach(function(preset) {
                if (presets[preset] === undefined) {
                    console.error('Unknown preset: ' + preset + ' in category ' + category.name);
                    process.exit(1);
                }
            });
        }
    });
}

function validatePresetFields(presets, fields) {
    var presets = rp('presets.json'),
        fields = rp('fields.json');
    _.forEach(presets, function(preset) {
        if (preset.fields) {
            preset.fields.forEach(function(field) {
                if (fields[field] === undefined) {
                    console.error('Unknown preset field: ' + field + ' in preset ' + preset.name);
                    process.exit(1);
                }
            });
        }
    });
}

var categories = generateCategories(),
    fields = generateFields(),
    presets = generatePresets();

// additional consistency checks
validateCategoryPresets(categories, presets.presets);
validatePresetFields(presets.presets, fields);

// Save individual data files
fs.writeFileSync('data/presets/categories.json', stringify(categories));
fs.writeFileSync('data/presets/fields.json', stringify(fields));
fs.writeFileSync('data/presets/presets.json', stringify(presets.presets));
fs.writeFileSync('js/id/core/area_keys.js', '/* jshint -W109 */\niD.areaKeys = ' + stringify(presets.areaKeys) + ';');
fs.writeFileSync('data/presets.yaml', YAML.dump({en: {presets: presets.presetsYaml}}));

// Push changes from data/core.yaml into en.json
var core = YAML.load(fs.readFileSync('data/core.yaml', 'utf8'));
var presets = {en: {presets: translations}};
var en = _.merge(core, presets);
fs.writeFileSync('dist/locales/en.json', stringify(en.en));

fs.writeFileSync('data/data.js', 'iD.data = ' + stringify({
    deprecated: r('deprecated.json'),
    discarded: r('discarded.json'),
    imagery: r('imagery.json'),
    wikipedia: r('wikipedia.json'),
    presets: {
        presets: rp('presets.json'),
        defaults: rp('defaults.json'),
        categories: rp('categories.json'),
        fields: rp('fields.json')
    },
    imperial: r('imperial.json'),
    featureIcons: r('feature-icons.json'),
    operations: r('operations-sprite.json'),
    locales: r('locales.json'),
    en: read('dist/locales/en.json'),
    suggestions: r('name-suggestions.json')
}) + ';');