package main

import (
	"fmt"
	"log/slog"
	"regexp"
	"strings"

	"focs.ji.sjtu.edu.cn/git/FOCS-dev/JOJ3/internal/stage"
	"github.com/go-git/go-git/v5"
	"github.com/koding/multiconfig"
)

type Conf struct {
	SandboxExecServer string `default:"localhost:5051"`
	SandboxToken      string `default:""`
	LogLevel          int    `default:"0"`
	OutputPath        string `default:"joj3_result.json"`
	Stages            []struct {
		Name     string
		Executor struct {
			Name string
			With struct {
				Default stage.Cmd
				Cases   []OptionalCmd
			}
		}
		Parser struct {
			Name string
			With interface{}
		}
	}
}

type OptionalCmd struct {
	Args   *[]string
	Env    *[]string
	Stdin  *stage.CmdFile
	Stdout *stage.CmdFile
	Stderr *stage.CmdFile

	CPULimit     *uint64
	RealCPULimit *uint64
	ClockLimit   *uint64
	MemoryLimit  *uint64
	StackLimit   *uint64
	ProcLimit    *uint64
	CPURateLimit *uint64
	CPUSetLimit  *string

	CopyIn       *map[string]stage.CmdFile
	CopyInCached *map[string]string
	CopyInCwd    *bool

	CopyOut       *[]string
	CopyOutCached *[]string
	CopyOutMax    *uint64
	CopyOutDir    *string

	TTY               *bool
	StrictMemoryLimit *bool
	DataSegmentLimit  *bool
	AddressSpaceLimit *bool
}

func parseConfFile(path string) (conf Conf, err error) {
	d := &multiconfig.DefaultLoader{}
	d.Loader = multiconfig.MultiLoader(
		&multiconfig.TagLoader{},
		&multiconfig.JSONLoader{Path: path},
	)
	d.Validator = multiconfig.MultiValidator(&multiconfig.RequiredValidator{})
	if err = d.Load(&conf); err != nil {
		slog.Error("parse stages conf", "error", err)
		return
	}
	if err = d.Validate(&conf); err != nil {
		slog.Error("validate stages conf", "error", err)
		return
	}
	return
}

func validateHw(hw string) error {
	matched, err := regexp.MatchString(`^hw[0-9]+$`, hw)
	if err != nil {
		return fmt.Errorf("error compiling regex: %w", err)
	}
	if !matched {
		return fmt.Errorf("error: hw does not match the required pattern")
	}
	return nil
}

func commitMsgToConf() (conf Conf, err error) {
	r, err := git.PlainOpen(".")
	if err != nil {
		return
	}

	ref, err := r.Head()
	if err != nil {
		return
	}

	commit, err := r.CommitObject(ref.Hash())
	if err != nil {
		return
	}

	file := "conf.json"

	msg := commit.Message
	slog.Debug("commit msg to conf", "msg", msg)
	if msg == "" {
		conf, err = parseConfFile(file)
		return
	}

	line := strings.Split(msg, "\n")[0]

	words := strings.Fields(line)

	head := words[0]
	var hw string

	if strings.HasSuffix(head, ":") || strings.HasSuffix(head, ".") {
		head = head[:len(head)-1]
	}

	switch head {
	case "feat", "fix", "refactor", "perf", "test", "build", "revert":
		// TODO: Decide strategy to give students error
		// if len(words) < 2 {
		// 	return Conf{}, fmt.Errorf("error: hw not assigned")
		// }
		if len(words) >= 2 {
			hw = words[1]
			if err = validateHw(hw); err == nil {
				file = strings.Replace(file, "conf", "conf-"+hw+"-cq", 1)
			}
		}
	case "joj", "grading":
		// TODO: Decide strategy to give students error
		// if len(words) < 2 {
		// 	return Conf{}, fmt.Errorf("error: hw not assigned")
		// }
		if len(words) >= 2 {
			hw = words[1]
			if err = validateHw(hw); err == nil {
				file = strings.Replace(file, "conf", "conf-"+hw+"-oj", 1)
			}
		}
	}

	conf, err = parseConfFile(file)
	return
}