/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.protolog.tool

import com.android.json.stream.JsonWriter
import com.github.javaparser.ast.CompilationUnit
import com.android.protolog.tool.Constants.VERSION
import com.github.javaparser.ast.expr.MethodCallExpr
import java.io.StringWriter

class ViewerConfigBuilder(
    private val processor: ProtoLogCallProcessor
) {
    private fun addLogCall(logCall: LogCall, context: ParsingContext) {
        val group = logCall.logGroup
        val messageString = logCall.messageString
        if (group.enabled) {
            val key = logCall.key()
            if (statements.containsKey(key)) {
                if (statements[key] != logCall) {
                    throw HashCollisionException(
                            "Please modify the log message \"$messageString\" " +
                                    "or \"${statements[key]}\" - their hashes are equal.", context)
                }
            } else {
                groups.add(group)
                statements[key] = logCall
            }
        }
    }

    private val statements: MutableMap<Int, LogCall> = mutableMapOf()
    private val groups: MutableSet<LogGroup> = mutableSetOf()

    fun findLogCalls(
        unit: CompilationUnit,
        path: String,
        packagePath: String
    ): List<Pair<LogCall, ParsingContext>> {
        val calls = mutableListOf<Pair<LogCall, ParsingContext>>()
        val visitor = object : ProtoLogCallVisitor {
            override fun processCall(
                call: MethodCallExpr,
                messageString: String,
                level: LogLevel,
                group: LogGroup
            ) {
                val logCall = LogCall(messageString, level, group, packagePath)
                val context = ParsingContext(path, call)
                calls.add(logCall to context)
            }
        }
        processor.process(unit, visitor, path)

        return calls
    }

    fun addLogCalls(calls: List<Pair<LogCall, ParsingContext>>) {
        calls.forEach { (logCall, context) ->
            addLogCall(logCall, context)
        }
    }

    fun build(): String {
        val stringWriter = StringWriter()
        val writer = JsonWriter(stringWriter)
        writer.setIndent("  ")
        writer.beginObject()
        writer.name("version")
        writer.value(VERSION)
        writer.name("messages")
        writer.beginObject()
        statements.toSortedMap().forEach { (key, value) ->
            writer.name(key.toString())
            writer.beginObject()
            writer.name("message")
            writer.value(value.messageString)
            writer.name("level")
            writer.value(value.logLevel.name)
            writer.name("group")
            writer.value(value.logGroup.name)
            writer.name("at")
            writer.value(value.position)
            writer.endObject()
        }
        writer.endObject()
        writer.name("groups")
        writer.beginObject()
        groups.toSortedSet(Comparator { o1, o2 -> o1.name.compareTo(o2.name) }).forEach { group ->
            writer.name(group.name)
            writer.beginObject()
            writer.name("tag")
            writer.value(group.tag)
            writer.endObject()
        }
        writer.endObject()
        writer.endObject()
        stringWriter.buffer.append('\n')
        return stringWriter.toString()
    }

    data class LogCall(
        val messageString: String,
        val logLevel: LogLevel,
        val logGroup: LogGroup,
        val position: String
    ) {
        fun key() = CodeUtils.hash(position, messageString, logLevel, logGroup)
    }
}