package com.restapi.controllers

import com.restapi.domain.*
import com.restapi.domain.Session.currentUser
import com.restapi.domain.Session.database
import com.restapi.domain.Session.findDataModelByEntityAndUniqId
import com.restapi.integ.Scripting
import io.ebean.CallableSql
import io.ebean.RawSqlBuilder
import io.javalin.http.BadRequestResponse
import io.javalin.http.Context
import io.javalin.http.NotFoundResponse
import io.javalin.http.bodyAsClass
import org.slf4j.LoggerFactory
import java.sql.Types
import java.time.LocalDate
import java.time.LocalDateTime
import java.time.LocalTime
import java.time.format.DateTimeFormatter

enum class QueryParamType {
    STRING, NUMBER, DATETIME, DATE
}

data class QueryParam(val type: QueryParamType, val value: String) {
    fun getValue(): Any {
        return when (type) {
            QueryParamType.STRING -> value
            QueryParamType.NUMBER -> if (value.matches(Regex("\\d+"))) value.toLong() else value.toDouble()
            QueryParamType.DATETIME -> LocalDateTime.parse(value, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"))
            QueryParamType.DATE -> LocalDate.parse(value, DateTimeFormatter.ofPattern("yyyy-MM-dd"))
        }
    }
}

data class RawQuery(
    val sql: String,
    val params: Map<String, QueryParam>
)
data class QueryById(
    val params: List<QueryParam>
)

enum class ResultType {
    INTEGER, DECIMAL, STRING, DATETIME, ARRAY, OBJECT
}

data class RejectAction(val reason: String)
data class StoredProcedure(val input: Map<String, Any>, val output: Map<String, ResultType> = hashMapOf())

object Entities {
    private val logger = LoggerFactory.getLogger("Entities")
    fun delete(ctx: Context) {
        val e = database.findDataModelByEntityAndUniqId(ctx.pathParam("entity"), ctx.pathParam("id"))
        e.deletedBy = Session.currentUser()
        e.deletedOn = LocalDateTime.now()
        e.update()
        e.delete()
    }

    fun patch(ctx: Context) {
        val e = database.findDataModelByEntityAndUniqId(ctx.pathParam("entity"), ctx.pathParam("id"))
        val pv = ctx.bodyAsClass<Map<String, Any>>()
        pv.forEach { (key, value) ->
            e.data[key] = value;
        }

        e.update()
    }

    fun update(ctx: Context) {
        val purgeExisting = ctx.queryParam("purge")?.toBooleanStrictOrNull() == true
        val e = database.findDataModelByEntityAndUniqId(ctx.pathParam("entity"), ctx.pathParam("id"))

        val newData = ctx.bodyAsClass<Map<String, Any>>()
        if (purgeExisting) {
            e.data.clear();
        }
        e.data.putAll(newData)

        e.update()
    }

    fun action(ctx: Context) {}
    fun approve(ctx: Context) {
        approveOrReject(ctx, ApprovalStatus.APPROVED)
    }

    fun reject(ctx: Context) {
        approveOrReject(ctx, ApprovalStatus.REJECTED)
    }

    private fun approveOrReject(ctx: Context, rejected: ApprovalStatus) {
        val e = database.findDataModelByEntityAndUniqId(ctx.pathParam("entity"), ctx.pathParam("id"))
        val reject = ctx.bodyAsClass<RejectAction>()
        e.approvalStatus = rejected
        e.comments.add(Comments(text = reject.reason, by = currentUser()))
        e.save()
    }

    fun executeScript(ctx: Context) {
        val name = ctx.pathParam("name")
        val file = ctx.pathParam("file")
        val params = ctx.bodyAsClass<Map<String, Any>>()
        ctx.json(
            Scripting.execute(file, name, params)
        )
    }

    fun executeStoredProcedure(ctx: Context) {
        val name = ctx.pathParam("name")
        val sp = ctx.bodyAsClass<StoredProcedure>()

        val inputParams = sp.input.entries.toList()
        val outputParams = sp.output.entries.toList()

        val placeholders = (0..inputParams.size + 1).joinToString(",") { "?" }

        val sql = "{call $name($placeholders)}"
        val cs: CallableSql = database.createCallableSql(sql)

        inputParams.forEachIndexed { index, entry ->
            cs.setParameter(index + 1, entry.value)
        }
        cs.setParameter(inputParams.size + 1, Session.currentTenant())

        outputParams.forEachIndexed { idx, entry ->
            when (entry.value) {
                ResultType.INTEGER -> cs.registerOut(idx + 1, Types.INTEGER)
                ResultType.DECIMAL -> cs.registerOut(idx + 1, Types.DOUBLE)
                ResultType.STRING -> cs.registerOut(idx + 1, Types.VARCHAR)
                ResultType.DATETIME -> cs.registerOut(idx + 1, Types.DATE)
                ResultType.ARRAY -> cs.registerOut(idx + 1, Types.ARRAY)
                ResultType.OBJECT -> cs.registerOut(idx + 1, Types.JAVA_OBJECT)
            }

        }
        val done = database.execute(cs)
        val output = outputParams.mapIndexed { index, entry ->
            Pair(entry.key, cs.getObject(index + 1))
        }.toMap()

        ctx.json(
            mapOf(
                "done" to done,
                "output" to output
            )
        )
    }

    fun sqlQueryRaw(ctx: Context) {
        val sql = ctx.bodyAsClass<RawQuery>()
        logger.warn("running sql ${sql.sql}, with params ${sql.params}")
        ctx.json(
            database.find(DataModel::class.java)
                .setRawSql(
                    RawSqlBuilder.parse(sql.sql).create()
                ).apply {
                    sql.params.forEach { (t, u) ->
                        setParameter(t, u.getValue())
                    }
                }
                .findList()
        )

    }

    fun sqlQueryById(ctx: Context) {
        val sql = ctx.bodyAsClass<QueryById>()
        val sqlId = ctx.pathParam("id")
        logger.warn("running sqlId $sqlId, with params ${sql.params}")

        val entity = ctx.pathParam("entity")
        val query = database.find(SqlModel::class.java)
            .where()
            .eq("entityName", entity)
            .eq("sqlId", sqlId)
            .findOne() ?: throw NotFoundResponse("sql not found for $entity, $sqlId")

        ctx.json(
            database.find(DataModel::class.java)
                .setRawSql(RawSqlBuilder.parse(query.sql).create())
                .apply {
                    sql.params.forEachIndexed { index, entry ->
                        setParameter(index+1, entry.getValue())
                    }
                }
                .findList()
        )

    }

    fun view(it: Context) {
        it.json(
            database.findDataModelByEntityAndUniqId(it.pathParam("entity"), it.pathParam("id"))
        )
    }

    fun create(ctx: Context) {

        val entity = ctx.pathParam("entity")


        //may be approval flow is configured?
        val setupEntity = database.find(EntityModel::class.java)
            .where()
            .eq("name", entity)
            .findOne()

        Session.creatSeq(entity)
        val dataModel = ctx.bodyAsClass<DataModel>().apply {
            this.entityName = entity
            if (this.uniqueIdentifier.isEmpty()) {
                this.uniqueIdentifier = Session.nextUniqId(entity)
            }
            this.approvalStatus = ApprovalStatus.APPROVED
        }

        database.save(
            dataModel.apply {
                if (setupEntity != null) {

                    val allowedFields = setupEntity.allowedFields.map { it.lowercase() }
                    if (allowedFields.isNotEmpty()) {

                        val moreFields =
                            dataModel.data.keys.map { it.lowercase() }.filter { !allowedFields.contains(it) }

                        if (moreFields.isNotEmpty()) {
                            logger.warn("Data Keys = ${dataModel.data.keys} is more than $allowedFields, extra fields = $moreFields")
                            throw BadRequestResponse("data contains more fields than allowed")
                        }

                        setupEntity.allowedFieldTypes.forEach { (key, expectedType) ->

                            val valueFromUser = dataModel.data[key] ?: return@forEach
                            val isDate = expectedType.equals("date", ignoreCase = true)
                            val isDateTime = expectedType.equals("datetime", ignoreCase = true)
                            val isTime = expectedType.equals("time", ignoreCase = true)
                            if (isDate || isDateTime || isTime) {
                                //this should be a string of a particular format
                                if (valueFromUser !is String) {
                                    throw BadRequestResponse("field $key, is of type ${valueFromUser.javaClass.simpleName} expected $expectedType")
                                } else {
                                    val dtPattern = Regex("^\\d{4}-\\d{2}-\\d{2}$")
                                    val dtmPattern = Regex("^\\d{4}-\\d{2}-\\d{2}\\s\\d{2}:\\d{2}$")
                                    val timePattern = Regex("^\\d{2}:\\d{2}$")


                                    if (isDate
                                        && !dtPattern.matches(valueFromUser)
                                        && !isValidDate(valueFromUser)
                                    ) {
                                        throw BadRequestResponse("field $key, is of type ${valueFromUser.javaClass.simpleName} expected $expectedType")
                                    }


                                    if (isDateTime
                                        && !dtmPattern.matches(valueFromUser)
                                        && !isValidDateTime(valueFromUser)
                                    ) {
                                        throw BadRequestResponse("field $key, is of type ${valueFromUser.javaClass.simpleName} expected $expectedType")
                                    }

                                    if (isTime
                                        && !timePattern.matches(valueFromUser)
                                        && !isValidTime(valueFromUser)
                                    ) {
                                        throw BadRequestResponse("field $key, is of type ${valueFromUser.javaClass.simpleName} expected $expectedType")
                                    }
                                }
                            }
                            if (valueFromUser.javaClass.simpleName != expectedType) {
                                throw BadRequestResponse("field $key, is of type ${valueFromUser.javaClass.simpleName} expected $expectedType")
                            }
                        }
                    }
                    if (!setupEntity.preSaveScript.isNullOrEmpty()) {
                        val ok = Scripting.execute(setupEntity.preSaveScript!!, "preSave", this) as Boolean
                        if (!ok) {
                            throw BadRequestResponse("PreSave Failed")
                        }
                    }

                    if (setupEntity.approvalLevels > 0) {

                        this.approvalStatus = ApprovalStatus.PENDING
                        this.requiredApprovalLevels = setupEntity.approvalLevels
                    }

                }
            }
        )

        if (setupEntity != null && !setupEntity.postSaveScript.isNullOrEmpty()) {
            Scripting.execute(setupEntity.postSaveScript!!, "postSave", dataModel)
        }
    }

    private fun isValidDate(f: String) = try {
        LocalDate.parse(f, DateTimeFormatter.ofPattern("yyyy-MM-dd"))
        true
    } catch (e: Exception) {
        false
    }

    private fun isValidDateTime(f: String) = try {
        LocalDateTime.parse(f, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"))
        true
    } catch (e: Exception) {
        false
    }

    private fun isValidTime(f: String) = try {
        LocalTime.parse(f, DateTimeFormatter.ofPattern("HH:mm"))
        true
    } catch (e: Exception) {
        false
    }
}