package control_case

import (
	"errors"
	"fmt"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"control/series"

	"github.com/che4web/go4rest"
	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

type ControlCaseController struct {
	*go4rest.ViewSet[ControlCase]
	db *gorm.DB
}

func NewControlCaseController(db *gorm.DB) *ControlCaseController {
	viewSet := go4rest.NewViewSet[ControlCase](db)
	viewSet.PreloadField = []string{"Params", "Params.InitialCondition"}

	return &ControlCaseController{
		ViewSet: viewSet,
		db:      db,
	}
}

type ParamsController struct {
	*go4rest.ViewSet[Params]
	db *gorm.DB
}

type InitialConditionController struct {
	*go4rest.ViewSet[InitialCondition]
	db *gorm.DB
}

func NewParamsController(db *gorm.DB) *ParamsController {
	viewSet := go4rest.NewViewSet[Params](db)
	viewSet.PreloadField = []string{"InitialCondition"}

	return &ParamsController{
		ViewSet: viewSet,
		db:      db,
	}
}

func NewInitialConditionController(db *gorm.DB) *InitialConditionController {
	return &InitialConditionController{
		ViewSet: go4rest.NewViewSet[InitialCondition](db),
		db:      db,
	}
}

type LaunchControlCaseRequest struct {
	ParamsID uint   `json:"params_id" binding:"required"`
	Name     string `json:"name"`
}

func (c *ControlCaseController) Launch(ctx *gin.Context) {
	var req LaunchControlCaseRequest
	if err := ctx.ShouldBindJSON(&req); err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var params Params
	if err := c.db.First(&params, req.ParamsID).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "params not found"})
		return
	}

	name := req.Name
	if strings.TrimSpace(name) == "" {
		name = fmt.Sprintf("case-%d", params.ID)
	}

	controlCase := ControlCase{
		Name:     name,
		ParamsID: params.ID,
		Status:   "N",
	}
	if err := c.db.Create(&controlCase).Error; err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	if err := c.db.Preload("Params").Preload("Params.InitialCondition").First(&controlCase, controlCase.ID).Error; err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	ctx.JSON(http.StatusCreated, controlCase)
}

type CSVSeriesResponse struct {
	Columns []string        `json:"columns"`
	Rows    [][]interface{} `json:"rows"`
}

type FFTPoint = series.SpectrumPoint

type PSISpectrumResponse struct {
	TimeStep float64               `json:"time_step"`
	Points   map[string][]FFTPoint `json:"points"`
}

type InitialConditionResponse struct {
	InitialCondition InitialCondition `json:"initial_condition"`
}

func (c *ControlCaseController) ChartData(ctx *gin.Context) {
	id, err := strconv.ParseUint(ctx.Param("id"), 10, 32)
	if err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid ID"})
		return
	}

	var controlCase ControlCase
	if err := c.db.Preload("Params").First(&controlCase, id).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "record not found"})
		return
	}

	csvPath := controlCase.FooCSVPath()
	data, ok := readCSVResponse(ctx, csvPath)
	if !ok {
		return
	}
	if len(data.Columns) == 0 {
		ctx.JSON(http.StatusOK, CSVSeriesResponse{Columns: []string{}, Rows: [][]interface{}{}})
		return
	}

	rows := make([][]interface{}, 0, len(data.Rows))
	for _, record := range data.Rows {
		row := make([]interface{}, 0, len(record))
		for _, value := range record {
			trimmed := strings.TrimSpace(value)
			if f, err := strconv.ParseFloat(trimmed, 64); err == nil {
				row = append(row, f)
			} else {
				row = append(row, trimmed)
			}
		}
		rows = append(rows, row)
	}

	ctx.JSON(http.StatusOK, CSVSeriesResponse{Columns: data.Columns, Rows: rows})
}

func (c *ControlCaseController) PSISpectrum(ctx *gin.Context) {
	id, err := strconv.ParseUint(ctx.Param("id"), 10, 32)
	if err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid ID"})
		return
	}

	var controlCase ControlCase
	if err := c.db.Preload("Params").First(&controlCase, id).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "record not found"})
		return
	}

	csvPath := controlCase.FooCSVPath()
	data, ok := readCSVResponse(ctx, csvPath)
	if !ok {
		return
	}
	if len(data.Rows) == 0 {
		ctx.JSON(http.StatusOK, PSISpectrumResponse{Points: map[string][]FFTPoint{}})
		return
	}

	columns, err := data.NumericColumns("t", "psi_m", "psi_l")
	if err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	times, psiM, psiL := columns[0], columns[1], columns[2]

	timeStep := series.AverageDelta(times)
	if timeStep <= 0 {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid time step"})
		return
	}

	ctx.JSON(http.StatusOK, PSISpectrumResponse{
		TimeStep: timeStep,
		Points: map[string][]FFTPoint{
			"psi_m": series.SpectrumPoints(psiM, timeStep),
			"psi_l": series.SpectrumPoints(psiL, timeStep),
		},
	})
}

func readCSVResponse(ctx *gin.Context, csvPath string) (*series.CSVData, bool) {
	data, err := series.ReadCSV(csvPath)
	if err == nil {
		return data, true
	}
	if errors.Is(err, os.ErrNotExist) {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "csv file not found"})
	} else {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
	}
	return nil, false
}

func (c *ControlCaseController) FieldMap(ctx *gin.Context) {
	id, err := strconv.ParseUint(ctx.Param("id"), 10, 32)
	if err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid ID"})
		return
	}

	timeValue, err := strconv.ParseFloat(ctx.Query("time"), 64)
	if err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid time"})
		return
	}

	var controlCase ControlCase
	if err := c.db.First(&controlCase, id).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "record not found"})
		return
	}

	result, err := ReadNearestFieldMap(controlCase.StorageH5Path(), timeValue)
	if err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	ctx.JSON(http.StatusOK, result)
}

func (c *ControlCaseController) CreateInitialCondition(ctx *gin.Context) {
	id, err := strconv.ParseUint(ctx.Param("id"), 10, 32)
	if err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid ID"})
		return
	}

	var controlCase ControlCase
	if err := c.db.First(&controlCase, id).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "record not found"})
		return
	}

	outputPath := filepath.Join(BASE_DIR, "initial_conditions", fmt.Sprintf("control_case_%d", controlCase.ID), "storage.h5")
	if err := controlCase.CreateStorageH5FromLastState(outputPath); err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	initialCondition := InitialCondition{
		Name:     fmt.Sprintf("control-case-%d", controlCase.ID),
		FilePath: outputPath,
	}
	if err := c.db.Where("file_path = ?", outputPath).Assign(initialCondition).FirstOrCreate(&initialCondition).Error; err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	ctx.JSON(http.StatusOK, InitialConditionResponse{InitialCondition: initialCondition})
}