package promptkit

import (
	"context"
	"errors"
	"fmt"
	"strings"

	"gitea.maximumdirect.net/eric/promptkit/internal/domain"
	"gitea.maximumdirect.net/eric/promptkit/internal/jsonvalue"
	"gitea.maximumdirect.net/eric/promptkit/internal/profile"
)

// OpenAICompatibleProfile returns an ordinary in-memory Profile for an
// OpenAI-compatible chat-completions endpoint.
//
// It does not register global state, maintain a model catalog, or resolve
// credentials. If APIKeyRequired is true, callers satisfy it with
// RunRequest.APIKey or an explicit request ExecutionTargetOverride.APIKeyEnv.
// Raw API keys do not belong in profiles.
//
// The function copies the ExtraParams map itself but does not recursively copy
// nested values. Validation and a deep copy occur when NewEngine applies a
// WithProfiles option containing the returned Profile.
func OpenAICompatibleProfile(cfg OpenAICompatibleProfileConfig) Profile {
	return Profile{
		ID:              cfg.ID,
		BackendID:       cfg.BackendID,
		Endpoint:        cfg.Endpoint,
		Model:           cfg.Model,
		Temperature:     cfg.Temperature,
		MaxTokens:       cfg.MaxTokens,
		TopP:            cfg.TopP,
		TimeoutSeconds:  cfg.TimeoutSeconds,
		ServiceTier:     cfg.ServiceTier,
		ReasoningEffort: cfg.ReasoningEffort,
		APIKeyRequired:  cfg.APIKeyRequired,
		ExtraParams:     copyShallowAnyMap(cfg.ExtraParams),
	}
}

func copyShallowAnyMap(src map[string]any) map[string]any {
	if src == nil {
		return nil
	}
	out := make(map[string]any, len(src))
	for k, v := range src {
		out[k] = v
	}
	return out
}

type memoryProfileRepository struct {
	profiles map[string]domain.ExecutionProfile
}

func newMemoryProfileRepository(profiles []Profile) (*memoryProfileRepository, error) {
	repo := &memoryProfileRepository{profiles: make(map[string]domain.ExecutionProfile, len(profiles))}
	for _, publicProfile := range profiles {
		prof, err := toDomainProfile(publicProfile)
		if err != nil {
			return nil, err
		}
		if _, exists := repo.profiles[prof.ID]; exists {
			return nil, fmt.Errorf("duplicate profile id %q", prof.ID)
		}
		repo.profiles[prof.ID] = prof
	}
	return repo, nil
}

func (r *memoryProfileRepository) GetProfile(_ context.Context, id string) (*domain.ExecutionProfile, error) {
	if r == nil {
		return nil, profile.ErrProfileNotFound
	}
	prof, ok := r.profiles[id]
	if !ok {
		return nil, profile.ErrProfileNotFound
	}
	prof.ExtraParams = copyAnyMap(prof.ExtraParams)
	return &prof, nil
}

func toDomainProfile(publicProfile Profile) (domain.ExecutionProfile, error) {
	extraParams, err := jsonvalue.CopyMap(publicProfile.ExtraParams)
	if err != nil {
		return domain.ExecutionProfile{}, err
	}
	prof := domain.ExecutionProfile{
		ID:              strings.TrimSpace(publicProfile.ID),
		BackendID:       strings.TrimSpace(publicProfile.BackendID),
		Endpoint:        publicProfile.Endpoint,
		Model:           publicProfile.Model,
		Temperature:     publicProfile.Temperature,
		MaxTokens:       publicProfile.MaxTokens,
		TopP:            publicProfile.TopP,
		TimeoutSeconds:  publicProfile.TimeoutSeconds,
		ServiceTier:     publicProfile.ServiceTier,
		ReasoningEffort: publicProfile.ReasoningEffort,
		APIKeyRequired:  publicProfile.APIKeyRequired,
		ExtraParams:     extraParams,
	}
	if err := validatePublicProfile(prof); err != nil {
		return domain.ExecutionProfile{}, err
	}
	return prof, nil
}

func validatePublicProfile(prof domain.ExecutionProfile) error {
	if strings.TrimSpace(prof.ID) == "" {
		return errors.New("id is required")
	}
	if strings.TrimSpace(prof.BackendID) == "" && strings.TrimSpace(prof.Endpoint) == "" {
		return errors.New("backend or endpoint is required")
	}
	if strings.TrimSpace(prof.Model) == "" {
		return errors.New("model is required")
	}
	if prof.Temperature < 0 || prof.Temperature > 2 {
		return errors.New("temperature must be between 0 and 2")
	}
	if prof.MaxTokens < 0 {
		return errors.New("max_tokens must be greater than or equal to 0")
	}
	if prof.TopP < 0 || prof.TopP > 1 {
		return errors.New("top_p must be between 0 and 1")
	}
	if prof.TimeoutSeconds < 0 {
		return errors.New("timeout_seconds must be greater than or equal to 0")
	}
	return nil
}