got a exporter for forecasting

internal/handler/forecast.go

@@ -0,0 +1,149 @@
+package handler
+
+import (
+	"Engine/internal/database"
+	"Engine/internal/model"
+	"encoding/json"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+type ForecastHandler struct {
+	budgets *database.BudgetRepo
+	actuals *database.ActualsRepo
+}
+
+func NewForecastHandler(budgets *database.BudgetRepo, actuals *database.ActualsRepo) *ForecastHandler {
+	return &ForecastHandler{budgets: budgets, actuals: actuals}
+}
+
+// GET /api/v1/forecast/export?dept=ENG&year=2024&version=original
+func (h *ForecastHandler) Export(w http.ResponseWriter, r *http.Request) {
+	dept := r.URL.Query().Get("dept")
+	yearStr := r.URL.Query().Get("year")
+	version := model.BudgetVersion(r.URL.Query().Get("version"))
+
+	if dept == "" {
+		writeError(w, http.StatusBadRequest, "dept is required")
+		return
+	}
+	year, err := strconv.Atoi(yearStr)
+	if err != nil || year < 1 {
+		writeError(w, http.StatusBadRequest, "year must be a valid integer")
+		return
+	}
+	if version == "" {
+		version = model.VersionOriginal
+	}
+
+	// collect actuals for all 12 periods
+	var periodActuals []model.ForecastPeriodRow
+	for period := 1; period <= 12; period++ {
+		byGL, err := h.actuals.ListByPeriod(r.Context(), year, period, dept)
+		if err != nil {
+			writeError(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+		for glCode, amount := range byGL {
+			periodActuals = append(periodActuals, model.ForecastPeriodRow{
+				FiscalPeriod: period,
+				GLCode:       glCode,
+				Amount:       amount,
+			})
+		}
+	}
+
+	// collect budget for all 12 periods
+	var periodBudget []model.ForecastPeriodRow
+	for period := 1; period <= 12; period++ {
+		rows, err := h.budgets.List(r.Context(), year, period, dept, version)
+		if err != nil {
+			writeError(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+		for _, b := range rows {
+			periodBudget = append(periodBudget, model.ForecastPeriodRow{
+				FiscalPeriod: period,
+				GLCode:       b.GLCode,
+				GLType:       b.GLType,
+				Amount:       b.Amount,
+				Currency:     b.Currency,
+			})
+		}
+	}
+
+	// remaining periods = periods with no actuals yet
+	actualPeriods := map[int]bool{}
+	for _, a := range periodActuals {
+		actualPeriods[a.FiscalPeriod] = true
+	}
+	var remaining []int
+	for p := 1; p <= 12; p++ {
+		if !actualPeriods[p] {
+			remaining = append(remaining, p)
+		}
+	}
+
+	writeJSON(w, http.StatusOK, model.ForecastExport{
+		Department:       dept,
+		FiscalYear:       year,
+		Version:          version,
+		PeriodsActual:    periodActuals,
+		PeriodsBudget:    periodBudget,
+		RemainingPeriods: remaining,
+	})
+}
+
+// POST /api/v1/forecast/ingest
+func (h *ForecastHandler) Ingest(w http.ResponseWriter, r *http.Request) {
+	var req model.ForecastIngestRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if errs := req.Valid(); len(errs) > 0 {
+		writeError(w, http.StatusBadRequest, strings.Join(errs, "; "))
+		return
+	}
+
+	// resolve dept ID once — all lines share the same department
+	var deptID int
+	if err := h.budgets.DB().QueryRowContext(r.Context(),
+		`SELECT id FROM departments WHERE code = ?`, req.Department,
+	).Scan(&deptID); err != nil {
+		writeError(w, http.StatusBadRequest, "department not found: "+req.Department)
+		return
+	}
+
+	var created []*model.Budget
+	for _, line := range req.Lines {
+		// resolve GL account ID per line
+		var glID int
+		if err := h.budgets.DB().QueryRowContext(r.Context(),
+			`SELECT id FROM gl_accounts WHERE code = ?`, line.GLCode,
+		).Scan(&glID); err != nil {
+			writeError(w, http.StatusBadRequest, "gl_account not found: "+line.GLCode)
+			return
+		}
+
+		b, err := h.budgets.Create(r.Context(), model.CreateBudgetRequest{
+			FiscalYear:   req.FiscalYear,
+			FiscalPeriod: line.FiscalPeriod,
+			Version:      req.Version,
+			DepartmentID: deptID,
+			GLAccountID:  glID,
+			Amount:       line.Amount,
+			Currency:     line.Currency,
+			CreatedBy:    req.CreatedBy,
+		})
+		if err != nil {
+			writeError(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+		created = append(created, b)
+	}
+
+	writeJSON(w, http.StatusCreated, created)
+}