package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"

	"git.tilde.town/tildetown/bbj2/server/cmd/api"
	"git.tilde.town/tildetown/bbj2/server/cmd/config"
	"git.tilde.town/tildetown/bbj2/server/cmd/db"
	_ "github.com/mattn/go-sqlite3"
)

// TODO tests

func main() {
	var configFlag = flag.String("config", "config.yml", "A path to a config file.")
	var resetFlag = flag.Bool("reset", false, "reset the database. WARNING this wipes everything.")
	flag.Parse()
	logger := log.New(os.Stdout, "", log.Ldate|log.Ltime|log.Lshortfile)
	opts := &config.Options{
		ConfigPath: *configFlag,
		Reset:      *resetFlag,
		Logger:     logger,
	}

	err := _main(opts)
	if err != nil {
		logger.Fatalln(err.Error())
	}
}

/*

TODO my next initiative is doing /something/ about the database layer.

The amount of boiler plate involved in:

- prepare a statement
- prepare a result struct
- execute statement
- scan into result

is wild; the error handling is really out of control. I need to think of abstractions for this. The "easiest" is just making blunt, non performant functions that return structs and a single error, but that could get out of control too. In general I think not having raw sql ever in application code is a good place to start.

*/

func _main(opts *config.Options) error {
	cfg, err := config.ParseConfig(opts.ConfigPath)
	if err != nil {
		return fmt.Errorf("could not read config file '%s'", opts.ConfigPath)
	}

	opts.Config = *cfg

	teardown, err := db.Setup(*opts)
	if err != nil {
		return fmt.Errorf("could not initialize DB: %w", err)
	}
	defer teardown()

	err = db.EnsureSchema(*opts)
	if err != nil {
		return err
	}

	setupAPI(*opts)

	// TODO TLS or SSL or something
	opts.Logger.Printf("starting server at %s:%d", cfg.Host, cfg.Port)
	if err := http.ListenAndServe(fmt.Sprintf("%s:%d", cfg.Host, cfg.Port), nil); err != nil {
		return fmt.Errorf("http server exited with error: %w", err)
	}

	return nil
}

func handler(opts config.Options, f http.HandlerFunc) http.HandlerFunc {
	// TODO make this more real
	return func(w http.ResponseWriter, req *http.Request) {
		opts.Logger.Printf("<- %s", req.URL.Path)
		// TODO add user info to opts
		f(w, req)
	}
}

func setupAPI(opts config.Options) {
	handleFailedAPICreate := func(w http.ResponseWriter, err error) {
		opts.Logger.Printf("failed to create API: %s", err.Error())
		w.WriteHeader(500)
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(api.BBJResponse{
			Error: true,
			Data:  "server error check logs",
		})
	}

	// TODO could probably generalize this even further but it's fine for now

	http.HandleFunc("/instance_info", handler(opts, func(w http.ResponseWriter, req *http.Request) {
		a, err := api.NewAPI(opts, req)
		if err != nil {
			handleFailedAPICreate(w, err)
			return
		}
		api.Invoke(w, a.InstanceInfo)
	}))

	http.HandleFunc("/user_register", handler(opts, func(w http.ResponseWriter, req *http.Request) {
		a, err := api.NewAPI(opts, req)
		if err != nil {
			handleFailedAPICreate(w, err)
			return
		}
		api.Invoke(w, a.UserRegister)
	}))

}

/*
	http.HandleFunc("/check_auth", handler(opts, func(w http.ResponseWriter, req *http.Request) {
		if req.Method != "POST" {
			badMethod(w)
			return
		}

		type AuthArgs struct {
			Username string `json:"target_user"`
			AuthHash string `json:"target_hash"`
		}

		var args AuthArgs
		if err := json.NewDecoder(req.Body).Decode(&args); err != nil {
			invalidArgs(w)
			return
		}

		opts.Logf("got %s %s", args.Username, args.AuthHash)

		db := opts.DB

		stmt, err := db.Prepare("select auth_hash from users where user_name = ?")
		if err != nil {
			serverErr(w, err)
			return
		}
		defer stmt.Close()

		var authHash string
		err = stmt.QueryRow(args.Username).Scan(&authHash)
		if err != nil {
			if strings.Contains(err.Error(), "no rows in result") {
				opts.Logf("user not found")
				writeErrorResponse(w, 404, BBJResponse{
					Error: true,
					Data:  "user not found",
				})
			} else {
				serverErr(w, err)
			}
			return
		}

		// TODO unique constraint on user_name

		if authHash != args.AuthHash {
			http.Error(w, "incorrect password", 403)
			writeErrorResponse(w, 403, BBJResponse{
				Error: true,
				Data:  "incorrect password",
			})
			return
		}

		// TODO include usermap?
		writeResponse(w, BBJResponse{
			Data: true,
		})
	}))

	http.HandleFunc("/thread_index", handler(opts, func(w http.ResponseWriter, req *http.Request) {
		db := opts.DB
		rows, err := db.Query("SELECT * FROM threads JOIN messages ON threads.thread_id = messages.thread_id")
		if err != nil {
			serverErr(w, err)
			return
		}
		defer rows.Close()
		for rows.Next() {
			var id string
			err = rows.Scan(&id)
			if err != nil {
				serverErr(w, err)
				return
			}
			opts.Log(id)
		}
		writeResponse(w, BBJResponse{Data: "TODO"})
		// TODO
	}))

	http.HandleFunc("/thread_create", handler(opts, func(w http.ResponseWriter, req *http.Request) {
		if req.Method != "POST" {
			badMethod(w)
			return
		}

		// TODO make this getUserInfoFromReq or similar so we can use the user ID later
		user, err := getUserFromReq(opts, req)
		if err != nil {
			writeErrorResponse(w, 403, BBJResponse{
				Error: true,
				Data:  err.Error(),
			})
			return
		}

		type threadCreateArgs struct {
			Title   string
			Body    string
			SendRaw bool `json:"send_raw"`
		}

		var args threadCreateArgs
		if err := json.NewDecoder(req.Body).Decode(&args); err != nil {
			invalidArgs(w)
			return
		}

		if args.Title == "" || args.Body == "" {
			invalidArgs(w)
			return
		}

		db := opts.DB
		tx, err := db.Begin()
		if err != nil {
			serverErr(w, err)
			return
		}

		stmt, err := tx.Prepare("insert into threads VALUES ( ?, ?, ?, ?, ?, 0, 0, ? )")
		if err != nil {
			serverErr(w, err)
			return
		}
		defer stmt.Close()

		threadID, err := uuid.NewRandom()
		if err != nil {
			serverErr(w, err)
			return
		}
		now := time.Now()
		if _, err = stmt.Exec(
			threadID,
			user.ID,
			args.Title,
			now,
			now,
			user.Username,
		); err != nil {
			serverErr(w, err)
			return
		}

		stmt, err = tx.Prepare("insert into messages values ( ?, 1, ?, ?, 0, ?, ? )")
		if err != nil {
			serverErr(w, err)
			return
		}
		defer stmt.Close()

		if _, err = stmt.Exec(
			threadID,
			user.ID,
			now,
			args.Body,
			args.SendRaw,
		); err != nil {
			serverErr(w, err)
			return
		}

		if err = tx.Commit(); err != nil {
			serverErr(w, err)
			return
		}

		stmt, err = db.Prepare("select * from threads where thread_id = ? limit 1")
		if err != nil {
			serverErr(w, err)
			return
		}
		defer stmt.Close()

		t := &Thread{}

		// TODO fill in rest of thread
		if err = stmt.QueryRow(threadID).Scan(
			t.ID,
			t.Author,
			t.Title,
			t.LastMod,
			t.Created,
			t.ReplyCount,
			t.Pinned,
			t.LastAuthor,
		); err != nil {
			serverErr(w, err)
			return
		}

		stmt, err = db.Prepare("select * from messages where thread_id = ?")
		if err != nil {
			serverErr(w, err)
			return
		}
		defer stmt.Close()
		rows, err := stmt.Query(threadID)
		if err != nil {
			serverErr(w, err)
			return
		}

		t.Messages = []Message{}

		for rows.Next() {
			m := &Message{}
			if err := rows.Scan(
				m.ThreadID,
				m.PostID,
				m.Author,
				m.Created,
				m.Edited,
				m.Body,
				m.SendRaw,
			); err != nil {
				serverErr(w, err)
				return
			}
			t.Messages = append(t.Messages, *m)
		}

		writeResponse(w, BBJResponse{Data: t})

	}))
*/