import * as g from './generator';
import * as tsa from './tsAnalyzer';
import * as tsch from './tsCompilerHost';
import * as log from './logger';
import * as nameUnifier from './nameUnifier';
import * as ts from 'typescript';
import * as fs from 'fs';
import * as pathPlatformDependent from 'path';

const path = pathPlatformDependent.posix; // This works everythere, just use forward slashes

var defaultLibFilename = path.join(path.dirname(require.resolve("typescript").replace(/\\/g, '/')), "lib.es6.d.ts");

export default (project: g.IGenerationProject, tsAnalyzer: tsa.ITsAnalyzer, logger: log.ILogger, rootStateKey: string = null): g.IGenerationProcess => {
    return {
        run: () => runBase(false, project, tsAnalyzer, logger, rootStateKey),
        runRecurse: () => runBase(true, project, tsAnalyzer, logger, rootStateKey)
    }
}

function runBase(applyRecurse: boolean, project: g.IGenerationProject, tsAnalyzer: tsa.ITsAnalyzer, logger: log.ILogger, rootStateKey: string): Promise<any> {
    const writeCallback = (fn, c) => { project.writeFileCallback(fn, new Buffer(c, 'utf-8')); }
    function writeCursors(params: g.ILoadedParams, currentStateName: string, rootStateKey: string) {
        let stateFilePath = params.stateFilePath;
        let mainState = g.resolveState(params.data.states, currentStateName);
        if (!mainState)
            return;
        const stateAlias = g.createUnusedAlias(g.stateImportKey, params.data.imports);
        const bobfluxPrefix = g.resolveBobfluxPrefix(mainState);
        logger.info('Generating has been started for: ', stateFilePath);
        writeCallback(
            createCursorsFilePath(stateFilePath),
            g.createAutogeneratedHeader(project.version)
            + g.createFullImports(stateAlias, `./${params.data.fileName}`, params.data.imports)
            + createCursorsForStateFields(params, rootStateKey, params.data, `${stateAlias}.${mainState.typeName}`, mainState, bobfluxPrefix, stateAlias)
        );
        logger.info('Generating ended for: ', stateFilePath);
    }
    function createCursorsForStateFields(params: g.ILoadedParams, parentStateKey: string, data: tsa.IStateSourceData, mainStateTypeName: string, state: tsa.IStateData, bobfluxPrefix: string, stateAlias: string, prefix: string = null): string {
        let nexts: INextIteration[] = [];
        let inner = state.fields.map(f => {
            let key = parentStateKey === null ? g.composeCursorKey(parentStateKey, prefix, f.name) : g.composeCursorKey(prefix, f.name);
            if (applyRecurse && f.type.length == 1 && !f.type[0].isArray && g.isExternalState(f.type[0].name, data)) {
                let alias = g.getExternalAlias(f.type[0].name, data);
                let innerFilePath = path.join(path.dirname(data.filePath), alias.relativePath + '.ts');
                let innerSourceFile = g.resolveSourceFile(params.sourceFiles, innerFilePath);
                if (innerSourceFile) {
                    let innerData = tsAnalyzer.getSourceData(innerSourceFile, params.typeChecker);
                    let innerResolvedState = g.resolveState(innerData.states, alias.sourceType);
                    if (innerResolvedState)
                        writeCursors({
                            stateFilePath: innerSourceFile.path,
                            data: tsAnalyzer.getSourceData(innerSourceFile, params.typeChecker),
                            sourceFiles: params.sourceFiles,
                            typeChecker: params.typeChecker
                        }, alias.sourceType, g.composeCursorKey(parentStateKey, key));
                }
            }
            let fieldType = g.getFullType(f.type, data, stateAlias);
            let indexedCursor = '';
            f.type.forEach(t => {
                let states = data.states.filter(s => s.typeName === t.name);
                if (f.type.length == 1 && t.isArray) {
                    indexedCursor = createIndexedFieldCursor(prefix, key, bobfluxPrefix, states.length > 0 ? `${stateAlias}.${t.name}` : t.name, mainStateTypeName);
                    return;
                }
                if (states.length > 0)
                    nexts.push({ state: states[0], data: data, externalFileAlias: stateAlias, prefix: key });
                if (states.length > 1)
                    throw 'Two states with same name could not be parsed. It\'s compilation error.';
            });
            return createFieldCursor(prefix, key, bobfluxPrefix, fieldType, mainStateTypeName) + indexedCursor;
        }).join('\n');
        return inner + (nexts.length > 0 ? '\n' : '') + nexts.map(n => createCursorsForStateFields(params, parentStateKey, n.data, mainStateTypeName, n.state, bobfluxPrefix, n.externalFileAlias, n.prefix)).join('\n');
    }
    return new Promise((f, r) => {
        g.loadSourceFiles(project, tsAnalyzer, logger)
            .then(p => {
                try {
                    writeCursors(p, project.appStateName, rootStateKey);
                } catch (e) {
                    logger.error('Error on cursors writing.', e);
                }
                f();
            })
            .catch(e => r(e));
    })
}

function createFieldCursor(prefix: string, key: string, bobfluxPrefix: string, typeName: string, baseStateTypeName: string): string {
    return `export function ${prefix === null ? key : nameUnifier.getStatePrefixFromKeyPrefix(prefix, nameUnifier.getStatePrefixFromKeyPrefix(key, ""))}(cursor: ${bobfluxPrefix}.ICursor<${baseStateTypeName}>): ${bobfluxPrefix}.ICursor<${typeName}> {
    return { key: cursor.key + '.${key}' };
}
`;
}

function createIndexedFieldCursor(prefix: string, key: string, bobfluxPrefix: string, typeName: string, baseStateTypeName: string): string {
    return `export function ${prefix === null ? key : nameUnifier.getStatePrefixFromKeyPrefix(prefix, nameUnifier.getStatePrefixFromKeyPrefix(key, ""))}Item(cursor: ${bobfluxPrefix}.ICursor<${baseStateTypeName}>, index: number): ${bobfluxPrefix}.ICursor<${typeName}> {
    return { key: cursor.key + '.${key}.' + index };
}
`;
}

export function createCursorsFilePath(stateFilePath: string): string {
    return `${path.join(path.dirname(stateFilePath), path.basename(stateFilePath).replace(path.extname(stateFilePath), ''))}.f.cursors.ts`;
}

interface INextIteration {
    externalFileAlias: string
    state: tsa.IStateData
    data: tsa.IStateSourceData
    prefix: string
}

interface IExternalChildState {
    state: string
    import: tsa.IImportData
    prefix: string
    parentFullPath: string
}