package server

import (
	"bytes"
	"context"
	"fmt"
	"log/slog"
	"net/http"

	"git.lastassault.de/speatzle/morffix/constants"
	"github.com/jackc/pgx/v5"
)

type TaskData struct {
	Libraries []Library
	Tasks     []Task
}

func handleTask(w http.ResponseWriter, r *http.Request) {
	if r.Method == "POST" {
		err := createTask(r.Context(), r)
		if err != nil {
			slog.ErrorContext(r.Context(), "Create Task", "err", err)
			http.Error(w, "Error Create Library: "+err.Error(), http.StatusInternalServerError)
			return
		}
	}

	data := TaskData{}

	rows, err := db.Query(r.Context(), "SELECT id, name, path, enable FROM libraries WHERE enable = $1", true)
	if err != nil {
		slog.ErrorContext(r.Context(), "Query Libraries", "err", err)
		http.Error(w, "Error Query Libraries: "+err.Error(), http.StatusInternalServerError)
		return
	}
	libraries, err := pgx.CollectRows[Library](rows, pgx.RowToStructByName[Library])
	if err != nil {
		slog.ErrorContext(r.Context(), "Collect Rows", "err", err)
		http.Error(w, "Error Query Libraries: "+err.Error(), http.StatusInternalServerError)
		return
	}
	data.Libraries = libraries

	rows, err = db.Query(r.Context(), "SELECT t.id AS id, l.id AS library, t.worker_id AS worker, t.type AS type, t.status AS status, f.path AS file FROM tasks t INNER JOIN files f ON f.id = t.file_id INNER JOIN libraries l ON l.id = f.library_id")
	if err != nil {
		slog.ErrorContext(r.Context(), "Query Tasks", "err", err)
		http.Error(w, "Error Query Tasks: "+err.Error(), http.StatusInternalServerError)
		return
	}
	tasks, err := pgx.CollectRows[Task](rows, pgx.RowToStructByName[Task])
	if err != nil {
		slog.ErrorContext(r.Context(), "Collect Tasks", "err", err)
		http.Error(w, "Error Query Tasks: "+err.Error(), http.StatusInternalServerError)
		return
	}
	data.Tasks = tasks

	buf := bytes.Buffer{}
	err = templates.ExecuteTemplate(&buf, constants.TASK_TEMPLATE_NAME, data)
	if err != nil {
		slog.ErrorContext(r.Context(), "Executing Task Template", "err", err)
		http.Error(w, "Error Executing Template: "+err.Error(), http.StatusInternalServerError)
		return
	}

	_, err = w.Write(buf.Bytes())
	if err != nil {
		slog.ErrorContext(r.Context(), "Writing http Response", "err", err)
	}
}

func createTask(ctx context.Context, r *http.Request) error {
	err := r.ParseForm()
	if err != nil {
		return fmt.Errorf("Parseing Form: %w", err)
	}
	library := r.FormValue("library")
	typ := r.FormValue("type")
	slog.Info("Got Task Create", "library", library, "type", typ)

	rows, err := db.Query(r.Context(), "SELECT id, path, size, missing FROM files where library_id = $1 AND missing = $2", library, false)
	if err != nil {
		return fmt.Errorf("Query Files: %w", err)
	}
	files, err := pgx.CollectRows[File](rows, pgx.RowToStructByName[File])
	if err != nil {
		return fmt.Errorf("Collect Files: %w", err)
	}

	tx, err := db.Begin(ctx)
	if err != nil {
		return fmt.Errorf("Begin Transaction: %w", err)
	}
	defer tx.Rollback(ctx)

	for _, file := range files {
		_, err = db.Exec(r.Context(), "INSERT INTO tasks (file_id, type, status) VALUES ($1,$2,$3)", file.ID, typ, 0)
		if err != nil {
			return fmt.Errorf("Inserting Task: %w", err)
		}
	}

	err = tx.Commit(ctx)
	if err != nil {
		return fmt.Errorf("Committing Transcation: %w", err)
	}

	return nil
}